JPH05319145A - Engine transmission control system - Google Patents

Abstract

PURPOSE:To give larger flexibility to the motion of a large off-road car by harmonizing an engine and the motion of a power transmission. CONSTITUTION:This system is furnished with a first electronic controller 90 to supply a transmission control signal to command a power shift transmission 64 to work with one of a plural number of advance gears by way of shifting the power shift transmission 64 and a second electronic controller 96 to supply an engine control signal to monitor actual engine speed by way of commanding an engine 52 to work with one of a large number of different desired engine speed. When desired ground speed is assigned by an operator, a transmission gear and engine speed required to perform desired speed is automatically selected, and automatic shift-up or shift-down is carried out. Additionally, this system has a comfort mode, a fuel a saving mode, a maximum horse power mode and an pseudo gear mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to electronic transmission control systems for self-propelled off-road vehicles having an engine and a multi-stage transmission, and more particularly to operating an engine / transmission combination efficiently. The present invention relates to a control system having a novel electronic controller and a novel method.

[0002]

BACKGROUND OF THE INVENTION Transmissions engage in a number of different patterns to power at different input / output drive ratios known as transmission gear ratios (or simply "gears"). It has a large number of gears, shafts, and clutch devices that can be used. In such a transmission, any gear can be selected by transmitting an electric signal of an appropriate pattern to the selection solenoid actuator of the hydraulic valve. The electrically controlled transmission can solve the problems that occur when mechanically connecting operator-initiated control to a large multi-stage transmission, which is the type of transmission required for many types of heavy duty off-road vehicles. Microprocessor-based electronic controllers for transmissions have been used by companies for many years. An example of such an electronic controller is disclosed in U.S. Pat. No. 4,425,620, "Electronic Control for Transmissions," which is hereby incorporated by reference. The patent discloses a microprocessor-based electronic control system having a mode selection lever and an up / down shift mechanism pulsar lever for supporting the orientation and gears of the vehicle in which the operator intends to operate the transmission.

When the operator momentarily disengages the transmission clutch under load and then reengages the clutch, a shock is produced in a conventional transmission when the speed of the transmission output shaft is not aligned with ground speed. . The electronic control described in the above patent substantially eliminates that impact by automatically selecting the transmission gear that perfectly matches the transmission output to the ground speed of the off-road vehicle. The patent also discloses the special use of a ground speed matching algorithm designed to help eliminate impact. However, in the disclosed control system, rather than gradually engaging the transmission clutch electronically during a shift,
Simply turn the solenoid on and off. In conventional transmissions, clutch engagement speed relies on hydromechanical controls such as orifices and accumulators (one or more). By itself, such mechanical control cannot effectively provide smooth or shock-free shifting under all conditions.

In the field of agricultural and construction machinery it is known to use proportional actuator devices such as hydraulic valves operated by torque motors, which allow a relatively soft engagement and thus It can be avoided while shifting. Such proportional actuator devices are often operated with pulse width modulated (PWM) signals. The duty cycle of the PWM signal in this case varies proportionally to the DC value or desired average value that it is desired to generate by the actuator. An electronic control system using the above PWM signal to operate the transmission with impactless soft engagement is disclosed in US Pat. No. 4,855,913 "Electronic Control System for Power Shift Transmissions", which is also incorporated herein by reference. It is incorporated into the calligraphy.

While the aforementioned electronic transmission controls have proved useful, they control only half of the total engine / transmission combination. That is, it is only the transmission, not the engine. When considering the combination of engine and transmission, another issue is raised, as will be shown in the following discussion.

In older diesel power plants used in heavy duty off-road vehicles, the horsepower-engine speed curve peaked in a relatively narrow range of engine speeds.
This is illustrated by the torque curve 36 and horsepower curve 38 of FIG. 1, where the range in which almost only the engine is being driven is shown as the power range 40 of the curve 36 beyond the horizontal line 42. This relatively narrow power band 40 is in the engine speed range of about 1860 RPM to about 2000 RPM, where the vehicle is most efficiently operated and the maximum amount of available traction is withdrawn from the engine. Because of this type of torque-engine speed characteristic, represented by curve 36, an operator who needs to drive a vehicle near its maximum rated horsepower must obtain sufficient torque from the engine to perform its job. You have to move the transmission in the very correct gear.

Since such older engines operate efficiently only in a fairly narrow range of speeds, the problem of how to draw near maximum horsepower from the vehicle is a problem with many gears of 12, 16, 24 and even 36 gears. It was solved by the development of a transmission that has. Secondly, the addition of such gears greatly increases the cost of the transmission.
However, the maximum horsepower can be extracted from the engine over a wide range of speeds, running at a certain speed,
And the merit of being able to get almost full power from the engine has been worth justifying the increase in transmission costs.

Transmissions with a large number of gears have been very popular. In some applications, especially for some agricultural tractors, it is often desirable to move the vehicle at a relatively constant speed without adjusting the throttle or gear for variations in the load on the power plant. Uses of this type include those where the uniformity of seed sowing, fertilization, uptake or other results achieved is highly dependent on maintaining a relatively constant vehicle ground speed. In other uses, particularly in agriculture, operator attention is taken to steer or monitor tools on off-road vehicles. In addition, in some uses, operators desire the vehicle to run at a constant speed in a single gear to minimize wear on the power plant. In yet another use, some gearshifts can be effectively performed by simply stopping the current operation. For example, when cultivating a field deeply, the tractor immediately stops moving due to a braking action caused by a plow that is buried in the ground, so the gears of the tractor cannot be easily switched. For this reason, many farm owners are accustomed to setting the tractor to run with a single gear, single speed adjustment for certain uses. This approach creates the problem of excessive fuel consumption.

Recently, manufacturers of large diesel engines, such as the Cummins Engine Company (Columbus, Indiana, USA), have created engines with wide and relatively flat torque-engine speed curves. Is now possible. These advances are possible in part due to advances in electronic control of the engine. Cummins Engine Company has a subsidiary that designs and manufactures electronic engine control systems for large diesel engines, Cummins Elctronics (Columbus, IN, USA). The torque curve 44 and horsepower curve 46 of FIG. 1 illustrate the wide range of performance ranges available with this new engine. Conspicuously, the torque curve 44 has a large, relatively flat or constant torque portion 48, which is about 170.
It is above the horizon 42 from 0 RPM to about 2100 RPM.

When the engine as described above is started to be built for an off-road vehicle, the drive system performance is optimized and the number of modes for driving an off-road vehicle with a truss mission is increased to solve the above problems. Can be considered.

It is a primary object of the present invention to integrate transmission operation and an electronically controlled engine with an electronic transmission control system to provide greater flexibility in driving large off-road vehicles. An important related object of the present invention is to provide multiple modes of off-road vehicle operation, including maximum horsepower mode and fuel economy mode, by using the transmission control system as a master controller.

Another object of the present invention is to employ a wide range of torque-engine speed characteristics in new diesel engines, with fewer gears than were required in conventional engine / transmission combinations, especially tractors and others. Is to enable almost stepless speed selection and gear adjustment in large off-road vehicles such as agricultural equipment.

Yet another object of the present invention is to provide a pseudo gear mode for the engine / transmission combination to make the operator think that the off-road vehicle has more gears than are actually present. ..

[0014]

According to the present invention devised to achieve the above object, there is provided an electronic control system for a self-propelled off-road vehicle having a power shift transmission having an engine and a large number of gears. An electronic control system for controlling the power shift transmission and for supplying the engine with one or more control signals for designating a rotational speed at which the engine should operate. , A specific one of the forward gears in which the power shift transmission is to operate
A first electronic controller means operable under stored program control to provide a transmission control signal specifying one of the plurality of different engine speeds within a predetermined range. Second electronic controller means operable under stored program control for providing one or more engine control signals necessary to command the engine to operate, The first controller means is between a first electrical output means for instructing the transmission to operate in a particular gear specified by the current transmission control signal and the second electronic controller means. Communication means for transmitting and receiving digital signals by means of the engine control signal. Second electrical output means for instructing the engine to operate at a specified specific engine speed, and communication means for transmitting and receiving digital signals to and from the first electronic controller means. An electronic control system comprising:

[0015]

SUMMARY OF THE INVENTION The electronic control system of the present invention controls a transmission and produces at least one control signal to the engine to specify engine speed. The electronic control system operates the engine at a first electronic controller means for generating a shift control signal that specifies to which forward gear the transmission should be shifted, and at one of a number of different engine speeds within a predetermined range. And second electronic controller means for generating at least one engine control signal required to command the

The first controller means includes first electrical output means for instructing the transmission to operate in a particular gear specified by the latest transmission control signal. The second controller means includes second electrical output means for instructing the engine to operate at a specific engine speed indicated by the engine control signal. Both controller means
It has a communication means for transmitting / receiving a digital signal to / from the counterpart electronic controller means.

The electronic control system also includes display means, preferably connected to at least one of the controller means and responsive to and responsive to the control means. This display means is for indicating to the operator the current (operating) transmission gear and the current engine speed. The display means also displays other information (including information received from other controller means).

The electronic control system also preferably includes automated means for controlling the shifting to higher or lower gears. Automation means may also be provided as a means for generating a series of successive upshift or downshift instructions. Further, the system may include automatic or automatic ground speed adaptation means for determining which gear to shift next based at least in part on ground speed.

According to a second aspect of the invention, a second electronic control system is provided for the same basic application as described above. The control system provides a means for accepting the desired vehicle speed selected by the operator and the transmission control signals required to instruct the transmission to operate no matter which forward gear is commanded, as well as the range of possible engine speeds. Electronic controller means for providing at least one engine control signal required to command the engine to operate at any rotational speed. In the present system, the controller means includes first and second electrical output means for operating the engine at the engine rotation speed instructed by the engine control signal.

The controller means also includes first automatic means for responding to the operator's selection of transmission gears to the means for subsequently accepting the desired engine speed required to achieve the desired vehicle speed. As in the previous case, the controller means preferably includes a second automatic means for generating a series of gearshift commands. This shift command is preferably generated at a predetermined minimum time interval after the completion of the previous shift command, if any.

The second control system may further include operator input means for accepting from the operator one mode selection among a large number of modes in which the engine can be operated. Possible operating modes to select include fuel saving mode and maximum power mode.

In maximum power mode, the electronic control means selects the engine speed that produces substantially maximum power from the transmission gear and engine / transmission combination. In the fuel economy mode, the controller means selects from the transmission gear and engine / transmission combination an engine speed that achieves substantially optimal fuel economy.

According to the third aspect (method) of the present invention, a special operator interface can be provided to the self-propelled off-road vehicle. The method provides an indicator or other means to instruct the operator that the transmission has more forward gear than it actually does. This method was devised to take advantage of a new generation diesel drive with an electronic controller that operates at fairly high torque over a fairly wide range of engine speeds. For each actual gear, the engine is preferably operated at two different speeds and whether the vehicle has one narrow torque-engine speed curve and two separate gears for each actual transmission gear. Cause the operator to create such an illusion. Thus, for example, a transmission with 12 forward gears can appear to have 24 forward gears. In this way, even an operator with the habit of choosing a fixed transmission gear to get a certain vehicle speed, in a very familiar way, actually drives an off-road vehicle with much less gears. be able to.

The above, and other aspects, objects, features and advantages of the present invention will be fully understood from the following detailed description, which should be read with reference to the drawings, and from the claims.

[0025]

The following description of the present invention is merely an example in essence, and does not limit the invention described in the scope of the patent claims or its application and usage. In particular, those skilled in the art should understand that the disclosed contents (including hardware and software) can be modified and changed with ordinary knowledge in the art.

FIG. 2 shows an off-road vehicle drive system 50 utilizing the transmission control system 60 of the present invention.
Indicates. The vehicle drive system 50 includes an engine 52 with an electronic engine controller 54 that provides output to an engine output drive shaft 56 via a drive train that includes a coupling means 58 and an input drive shaft 62 of a transmission 64.
Is included. In the preferred embodiment of the invention, the transmission 64 is of the type having multiple gear ratios,
The gear ratio is selected by the operation of the hydraulic valve 66. The hydraulic valve is selected when the solenoid 68 is excited. Normally, each hydraulic valve shifts when the solenoid is energized, and when the solenoid is demagnetized, it is generally returned by the internal spring of the valve.

The transmission 64 also has a drive output shaft 68 and an output branch (PTO) shaft 70. Depending on how many gears the trans mission has, generally the trans mission has an additional intermediate shaft (not shown).
Is provided.

As indicated by the clutch devices 72, 74, 76, one or more clutch devices include shafts 62, 68, 70.
Is related to each axis, and its state is related gear (gear 8
(2, 84, etc.) are connected to their respective shafts or are freewheeling.

In a prototype vehicle using the system of the present invention, a model No. 1 of Fuji Steel Co., Ltd. manufactured by Fuji Steel Co., Ltd. (Kosai City, Shizuoka Prefecture) with 12 forward gears, 2 reverse gears and 8 clutches was used. EW16 transmission 6
Adopted as Cummins diesel engine model No. The NTA855 is adopted as the engine 52, and the Cummins Electronics off-highway engine controller is used as the engine transmission 54.
Adopted as.

The control system 60 also includes a controller system 90, a dashboard 92, a transmission control switch / lever set 94, an engine function / accessory control switch 96, a vehicle ignition switch 98, an engine throttle unit 100, and a controlled electric output unit 102. Have. Reprogramming panel 104
Can optionally be used to reprogram control system 90.

The transmission 64 has a conventional clutch pedal assembly 110 having a pedal 112 mounted on a spring-loaded pivoted lever 114, the transmission's master clutch (not shown), as indicated by the dotted line 116 indicating the mechanical coupling. It can be used to manually disengage

The control system 60 also includes one or more velocity sensor systems (of any known type). The engine speed sensor may be a variable reluctance sensor 118 that detects the teeth of the flywheel gear 120 that is connected to the engine output shaft 56 (detects the teeth that pass in front of the sensor 118). The transmission output speed is sensed by another sensor system that includes a variable magnetic reluctance sensor 122 that senses the passing teeth of a rotary gear 124 coupled to the output transmission drive shaft 68. The output shaft 68 is connected to the driven wheels 128 of the vehicle so that the sensor 122 indicates an apparent ground speed. As is well known, particularly in heavy farming work such as deep cultivating the ground, the driven wheels are likely to slip.

In order to obtain the true ground speed instruction, it is sufficient to read the true ground speed extremely accurately by using the ordinary radar horn unit 132 that bounces the microwave signal 134 from the ground surface 136. Alternatively, if the vehicle has a freewheeling tire, such as the tire 138 shown at the bottom right of FIG. 2, the passing teeth of the gear 144 carried by the axle 146 carrying the wheel and rim assembly of the tire 138 may be passed. By monitoring the, another variable reluctance sensor 142 can be used to obtain a true ground speed signal.

The electronic control system 90 includes ports 150 ...
With a suitable number of digital and analog input and output ports, such as 158, thick and thin lines 160-
Send and receive electrical signals as indicated at 180. Each wire represents one or more electrical circuits, and each wire may be a cable, wire, or wire harness (a fiber optic signal path may be used at one or more locations in the electrical circuit, if desired).

The controlled output unit 102 includes a power source section 18
2 and a power source switching relay unit 184 are provided. The control system 90 is provided with a monitoring timer circuit 186 that is electrically coupled to the relay of the power supply and that activates the relay.
If for some reason the watchdog timer is not periodically reset as determined by the microprocessor in control system 90, then limp home mode (limp
-Instruct the power switching unit to enter (home mode). Details of the internal hardware of electronic control system 90 and unit 102 are shown in detail in FIG. The details of the configuration of the controlled power supply unit 102 (including its parts 182 to 186 and the interface with the electronic control system 90) have been described in detail in the above-mentioned US patent application Ser. No. 07 / 700,629, and are omitted here. ..

The dashboard display unit 92 can be as simple or as complex as desired. A display unit 92 for a complex case is shown in FIG. 2 and is provided with a dedicated microprocessor 190. This microprocessor 1
The 90 can communicate with the electronic control system 90 via the line 160 by the serial port interface 192. The display unit 92 has a buffer / driver / latch (BDL) section 194, and signals for operating each individual display 196 to 208 are supplied through an electric wiring circuit represented by a line extending from the BDL section such as the line 210. Provided. The displays 196-208 may take any of the usual formats (e.g., shown as individual displays in this embodiment, but if desired, may be a two-dimensional flat panel display or cathode ray tube to show the same information). Can be used instead). The display unit 196 is a tachometer that indicates the actual engine speed, and may be either a digital type or an analog type display device. Display 1
98-204 preferably comprises a 7 segment light emitting diode (LED) display or liquid crystal display (LCD) with as many digits and decimal points as necessary to display the required value. The displays 198 and 200 preferably display the actual gear and the desired gear in two digits respectively. The displays 202 and 204 are preferably three-digit displays with a single decimal point between the second and third digits to display the actual ground speed and the desired ground speed, respectively. Display unit 2
06 is preferably a 20-40 character dot matrix display for indicating one or more alphanumeric messages or instructions, warning or error codes (or messages) indicating, for example, the current operating mode of the control system 90. is there. Longer full-text messages can also be represented by conventional panning techniques or successive partial representations of the message.

Display 208 is an optional backlit LCD bargraph display having approximately 28 separate bar segments, where every fifth segment is larger than the adjacent bar segment. This bar graph display is available from Phoenix International Corporation (Fargo, North Dakota, United States of America) as the assignee of the present application as part of a dashboard front panel for off-road vehicles. In the present invention, the display unit 208 is used for another new purpose. That is, it is used to relatively display where the current desired engine speed or the current actual ground speed is as viewed from the up-shift and down-shift points for the current gear. For example, terminal bar segment 21
2, 214 is illuminated to display the shift-down and shift-up points, while another segment, such as the segment 216 between the two terminal segments, is illuminated and illuminated to display the current engine speed. It will be possible. When the engine speed (or ground speed) changes, the segment 206 is turned off and the adjacent segment is turned on so that the position of the intermediate light emitting segment can be freely moved left and right on the display unit 208. . Thus, by the relative position of the illumination emission middle segment,
It shows how the desired engine speed (or actual ground speed) is changing with respect to the shift point. Alternatively, all bar segments to the left of segment 216 may be illuminated. Either way, the operator is graphically displayed with information about where the vehicle is operating in the current gear for the upshift and downshift points. Given the foregoing description, the construction and operation of dashboard display assembly 92 (including the internal controller and internal displays 196-208 represented by blocks 190-194) are within the skill of those in the art, and no further discussion is provided. Omit it.

The reprogramming (RP) panel 104 may be of any suitable or conventional type. For example, in a factory, the RP panel 104 may be a portable personal computer.
On the remote site from the factory, the RP panel 104 takes the form of a portable handheld calculator with a suitable multi-push button operator interface pad and a predetermined symbol display such as a dual row LCD display. Can also

As shown in FIG. 2, the operator switch
The set of levers 94 and 96 may take any conventional or suitable form for the off-road vehicle operator to communicate to the control system 90 the required operating instructions and modes.
Thus, the individual switches and levers shown and described below are only a few of the many possible sets of operator input devices that can be used for such operator interfaces. For example, a multi-push button keypad or a coded thumbwheel switch can be used to enter a desired value or desired mode command or digital display, and use individual switches and potentiometers for this purpose. You can also

The switch lever set 94 is used for selecting and assigning transmission commands. The set 94 includes switches 224, 226 and pivot lever assemblies 228, 230. Switch 224 is used to select the output mode of transmission operation and is in three positions: off (center position), maximum horsepower (left position for "maximum horsepower"), and fuel savings (right position for "fuel savings"). Position) is included. The switch 226 is used to select the operating mode of the transmission, the 2 position,
That is, it has a GS (left position for "ground speed") and a pulsar (right position). Lever assembly 228
Is used to select a direction with the pivot hand lever 232 and has three positions: neutral (center position), forward (left position), and reverse (right position). Base 234 of lever assembly 228
Has three switches 236, which indicate that the lever 232 is in the forward, neutral, and reverse positions, respectively.
238 and 240 may be provided. Assembly 228 preferably has a detent so that the lever remains in its final position and does not move. The lever assembly 230 has a pivot hand lever 242 which has three positions, a no-action position (center), an upper (left position) and a lower (right position).
The base 244 has limit switches 246 and 250, which are shown when the lever 242 is in the upper and lower positions, respectively. Easy to understand). Assembly 230 is preferably spring biased to return lever 242 to its central position when released. Switches 236-240 and 246-250 may be of any suitable type including microswitches, non-contact magnetically actuated reed switches or combinations thereof. The lever assemblies 228, 230 are preferably arranged such that the levers 232, 242 move back and forth in the direction of the vehicle longitudinal axis. Other lever or joystick arrangements than those described above may be used as long as the basic operator interface functions are fulfilled. The exact configuration used is not a limitation of the invention and other configurations are possible.

The set of switches 96 is used to select or specify either engine functions or commands or accessory functions or commands and includes two "on / off" changeover switches 256,258. The switch 256 is operated by a solenoid-excited hydraulic valve (not shown) so that P
Used to turn the TO axis on and off. Switch 258
Is used to specify whether the "droop" function of the engine controller 54 is on or off. When the droop function is on, the engine controller 54 causes the engine 52 to decelerate (i.e., reduce its RPM) as the load increases, similar to a normal engine. When the droop switch 258 is in the off position, even if the load on the engine changes considerably, the engine controller 5
No. 4 attempts to accurately maintain the rotation speed of the engine 52 at a desired engine rotation speed.

The selector and lever switches 224-258 described above are coupled to one or more wire harnesses shown in electrical circuit 180 of FIG. A part of this switch can be connected to the controlled output unit 102 if necessary. For example, if the vehicle is first turned on by the vehicle "on / off" switch 98, it is important to make sure that the directional lever 232 is in the neutral position before engaging any clutch of the transmission. Controlled output unit 1
The electrical interconnection between 02 and the switch sets 94, 96 is represented by line 260. Line 262 extends from controlled output unit 102 and
2 represents an electrical direct connection between the solenoid 2 and the solenoid bank 68 of the transmission 64. The functions and electrical connections required for the "limp home" operation are described in the two US patents and pending patent applications mentioned above and are therefore omitted here.

Clutch pedal assembly 11 shown in FIG.
0 also has switches 202 and 274, which are connected to the pedal 112, respectively.
Is used to detect that it is in its fully depressed and fully raised positions. The limit switches 202 and 274 may take any conventional suitable form such as microswitches, reed switches or a combination of the two.

The engine throttle lever 100 is mounted on a suitable base 278 and the engine throttle lever 100 has a suitable type position indicating device 280 such as a potentiometer, resolver, encoder or the like. An analog or digital signal is provided to the control system 90 via line 172 of device 280, the amount or value of which is indicative of the position or setting of lever 100. This signal is then sent to electronic engine controller 54 via electrical line 168. Also, the value of the electric signal on the line 172 is used as a throttle position command from the operator in the control system 90.
Read by. The throttle lever 100 preferably has a releaseable detent mechanism. The detent mechanism may be of any type, such as a small spring band brake (not shown) operated by a release button 284. The release button, once set by the operator, keeps the lever in place. One of ordinary skill in the art will recognize that a knob-equipped position indicating device such as a potentiometer may be used in place of the lever. Instead of the throttle lever 100 and its base 278, it is also possible to use a keypad with a suitable electronic latch circuit for holding the input value.

FIG. 3 shows a solenoid that must be excited in order to engage each gear of the Fuji Iron Works model EW16 transmission used in the prototype heavy-duty tractor system of the present invention. While the prototype system is the basis of the present disclosure, it will be understood by those skilled in the art that the discussions here apply equally to other transmissions, as transmissions from other companies also operate on similar principles. It should be possible. The transmission 64 has
Eight clutch devices are provided, each controlled by a solenoid actuated hydraulic valve. Reading pattern 290 of FIG. 3 from left to right, the solenoids Y, Z, X, W, V,
Labeled T, S, Q, the row (vertical direction) corresponds to each solenoid. Row (lateral) is direction (forward or reverse) and transmission gear (1 to 12)
Refers to. According to pattern 290, energizing the solenoids Y, V, S is required to reverse the first gear transmission, as indicated by the "X" in each row.
To select each direction and gear, pattern 290 shows that each direction and gear has a unique combination of three solenoids to excite. The structure and operation of the Fuji Steel transmission model EW16 are described in documents available from Fuji Steel, and are omitted here.

FIG. 4 is a detailed block diagram showing an electronic transmission control system 90 with selected external components from FIG. 2 (included in FIG. 4 to facilitate the description of FIG. 4). .. The control system 90 may be configured to include one large microprocessor-based controller or multiple small electronic controller devices such as controllers 301, 302 (which may be essentially the same structure). In one application example, the controller 301
Or if certain functional features of 302 are not utilized,
The cost of the controller can be reduced by simply removing (or not attaching) unused circuit components or integrated circuit chips.

The controller 301 is a microprocessor 30 with a suitable time base such as a crystal oscillator.
4, a random access memory (RAM) 310, a bus driver, a chip selection (BD / CS) circuit 308, and a read-only memory (ROM) 306, which is a microcomputer 303. The non-volatile read / write memory is also preferably provided as an electrically erasable programmable read only memory (EEPROM) 312. Further, the controller 301 is the electric circuit 18 of FIG.
A digital input circuit 316 with a buffer for reading the states of various operator interface devices connected to 0 is provided. The controller 301 also converts the input analog signal on line 320 to digital form.
The digital input circuit 318 and a DC power supply circuit with a filter for supplying a low voltage power supply to the analog circuit device are provided. The controller 301 further includes a frequency input circuit 324 that receives the pulsed waveform signals of the engine tachometer sensor 118 and conductors 326 and 328 of the ground speed unit, respectively. The ground speed unit may be any one of the three sensors 122, 132, 142 previously described in FIG. Multiple ground speed inputs can be utilized if desired. This means that, for example, the sensor 12
The apparent ground speed from 2 is detected by the sensor 132 or 142.
It may be effective when monitoring tractor wheel slip by comparing it to the true ground speed as defined by.

The controller 301 has a power output port 3
32 and 334. Each power output port is shown in Figure 2.
The four solenoids of the solenoid group 68 shown in are driven. Although not shown, the output circuits 332 and 33
4 preferably includes low value shunt resistors through which current to each solenoid flows. This is for generating an analog voltage proportional to the current, and the current is
Monitored by 18 as an analog input signal. As is well known, such a method is based on the solenoid drive circuit 3
Useful to monitor 24,334 for shorts and opens. Controller 301 may have additional digital outputs such as output port 336, high speed synchronous serial communication output port 338, low speed asynchronous serial communication port 339 and reprogramming panel input / output port 340. The power output port 336 is the transmission 64
May drive an additional power supply such as solenoid 342 used to engage the power take-off clutch. Serial communication port 338 is used to communicate with a similar serial communication port on the side of controller 302 via electrical line 344. The serial communication port 339 communicates with the dashboard display unit 92 via the electric line 345. The controllers 301 and 302 are respectively Motorola model No. It can be configured to include an MC68HC11 series microcontroller. Microcontroller is a high speed synchronous peripheral interface available at port 338 (runs between 50K baud and 1M baud)
And a general-purpose asynchronous transceiver that can be used as the port 339.

Inside, appropriate data, address, and control buses are provided (represented by electrical lines 346) for interconnecting the I / O ports or circuits to the microcomputer 303. Controlled power supply unit 102
Appropriate power connections to the terminals are made at terminals 348 and 349, and if desired, the vehicle battery voltage can be monitored using conventional techniques. The internal structure of controller 301 is described in detail in pending US patent application Ser. No. 07 / 700,629.

As shown in the lower part of FIG. 4, the controller 3
Additional controllers, such as 51 (the top of which is shown in dashed lines), may be interconnected to other controllers via serial communication ports such as port 358. This additional electrical connection is represented by line 354 and is a serial communication S
It is connected to the PI port 358. Controller 30
2 and 351 may be the same as or substantially similar to the controller 301. As described further below, all information needed to coordinate and operate two or more controllers is available from the American Society of Automotive Engineers (S
AE) Electrical circuit 3 using well known serial communication techniques such as those described in Serial Communication Standard J1708.
You can pass in both directions along 45. According to this method, the separate controllers forming the control system can be operated as one unit on a real-time basis.

The main advantage of using multiple controllers in the single control system 90 is that the manufacturing cost of the system 90 can be very matched to any application need.
In other words, one or more controllers 302 and 351 can be added to the control system 90 as needed in some applications if additional real-time computing power supplies or additional analog or digital I / O ports are required. For example, in the prototype system of the present invention, a controller 301 mainly handles real-time control and calculation requests to operate the transmission 64, while a transmission made by Fuji Steel and a diesel engine made by Cummins are used, while the controller 302 is It is mainly used to monitor and control the input / output signals from / to the electronic engine controller 54 in real time and drive the display unit 92. In this way, the entire software code needed to monitor and control the operation of this engine / transmission combination is split between the controllers 301 and 302, and all functions are short real-time, as will be described in more detail below. It can be executed within an interval.

Next, the input / output device (FIG. 4) attached to the controller 302 will be described. Controller 30
2 is provided with means for digital and analog input / output (I / O) circuits or ports 366-390, these means are provided by the input / output circuits of controller 301.
It is of the same type as the means provided in the port (reference number difference is 50). I / O circuits 366, 37
Since 4,382 and 384 are not used, they are not provided in the controller 302. That is, I / O
You do not have to solder or plug the necessary components or integrated circuits into the port.

In FIG. 4, block 392 represents the engine reference voltage signal (VREF) applied by circuit 394 to analog input circuit 368, which preferably has at least 8 bit resolution. Throttle pot 2
80 may also be attached to circuit 368 by conductor 396. The throttle pot 280 is the controller 3
No. 02 DC power supply unit 372 receives filtered power.

In the prototype system 60 of the present invention, the controller 302 sends a desired engine speed signal or command to the electronic engine controller 54 via signal path 398, which signal or command is output from port 386. Will be transmitted as a digital value. If engine controller 54 requires an analog signal rather than a digital signal, D / A converter 400 can perform this conversion. If used, the D / A converter 400 preferably has at least 8-bit resolution. Conductor 402 is part of line 168 shown in control system 90 and controller 54 of FIG.

FIG. 5 shows the relationship between the input voltage percentage (VREF) and the desired engine speed in a Cummins engine used in the prototype system 60 of the present invention. The analog input voltage on line 402 of FIG. 4 is interpreted as the desired engine speed command. This DC voltage level signal is output from the engine controller 54 as 1 of the value of the signal VREF.
It is sent to the engine controller 54 as a fraction of 00% (typically about 5 volts DC). This voltage signal VREF is depicted in FIG. 4 as block 392 and is monitored by analog input port 368. The normal range of engine speeds utilized by the transmission controller is from 850 RPM to 2100 RPM, these values (850 RPM and 2100 RPM) representing 10% and 80% of the VREF value, respectively. The minimum idle speed of the engine 52 is 650 RPM, and the throttle fully open unloaded engine speed is 2400 R.
It is PM. To perform the control described here, the engine need only be run between 850 RPM and 2100 RPM. This is the higher value of the desired engine speed signal (8
0%) gives a dead band of 20% and the lower value (10%) gives a dead band of 10%. Therefore, the electronic engine controller 54 and controller 90 shown in FIG.
The voltage command signal from D / A converter 400 can be monitored to ensure that there are no open or short circuit conditions.

When the engine controller 54 is receiving the command signal 402 within 10% to 80% of the value of the VREF signal, the controller 54 will generally be within the limits of the mechanical engine system to indicate the engine speed represented by this command. Do everything necessary to maintain the number. Generally, the controller 54 employs closed loop feedback by monitoring the engine speed and the pressure of the fuel pump in front of the mechanically timed fuel injector to adjust the fuel pump pressure to adjust the engine speed. Adjust. In another engine controller, the engine speed can be adjusted by another method such as changing the timing of fuel supply from the fuel injector while maintaining the fuel pressure constant. The particular method used by controller 54 to control engine speed is not critical, as long as engine speed can be controlled fairly accurately and quickly.

Those skilled in the art will recognize that other voltage levels or different control signals can be used for the desired engine speed command. For example, it is possible to perform digital communication between the controllers 54 and 90. In that case, the D / A converter 400 shown in FIG. 4 can be eliminated altogether and the desired engine speed can be transmitted as an 8-bit, 10-bit or 12-bit value. At this time, the integrity of information transfer is guaranteed using a bidirectional handshake method.

FIG. 6 shows three sets of data points used in connection with the ground speed matching function of the prototype system 90 of the present invention. The "asterisk" symbols represent 1000 RPM data points for each of the 12 forward gears, the "plus" symbols represent data points for 2000 RPM engine speed for the 12 forward gears, and the hollow squares are 300 for the forward gears.
Represents data points for 0 RPM engine speed. As explained previously, it is preferable to utilize ground speed matching whenever the transmission disengages briefly and then reengages when the vehicle is still in motion. If the vehicle is under load, or if disengagement continues long enough, then the actual vehicle speed and / or the actual engine speed will change (typically decrease). But after disengaging the transmission,
The engine speed may increase if the engine speed command signal is not reduced while removing the load from the engine that is slowing down. Under these conditions, the engine will start to increase its speed rapidly, if not already at the desired speed. As previously mentioned, if the transmission output shaft 68 is
If the speed of the transmission output shaft 62 does not match in consideration of the gear ratio of, the sway felt by the operator when the same transmission gear is re-engaged.
A shock will occur. If this happens (usually), large transient forces will be applied to the engaged gears and associated shafts and clutch systems of the transmission, resulting in transmission and engine wear and wear.

The automatic ground speed matching by the transmission controller is to largely avoid the shaking and impact by precisely matching the current engine speed to the ground speed in consideration of the gear ratio. According to this method, the movement of energy passing through the transmission can be minimized due to the difference in rotational speed between the input shaft and the output shaft of the transmission shaft. The graph of FIG. 6 shows transmissions of 1000 RPM, 2000 RPM, 3
Figure 6 shows the preferred gear when engaging at 000 RPM. The shape of the curve connecting the centers of 3000 RPM data points is 1
It is non-linear from the stage gear to the 12 stage gear. 2000RP
The curve for M and 1000 RPM data points is 300
It should be noted that it is similar to the 0 RPM curve and is directly proportional as a whole. Therefore, in the control system 90 of the present invention, only one set of values needs to be stored for each gear (preferably the two values representing the highest and lowest vehicle speeds for that 3000 RPM data point box). From these 12 sets of stored values, other R
The value for PM is interpolated immediately when needed, and when the operator re-engages the transmission, it determines to which gear the transmission should be shifted for ground speed matching. In particular, the desired gear for the 3000 RPM value is stored in a lookup table accessed by vehicle speed. So if the engine is 1000
It operates at RPM and the vehicle speed is 5.5 mph (about 8.
85 km), the vehicle speed to access the table is 16.5 mph (about 2
6.55 km). Next, when the reference table is accessed, the stored value for the vehicle speed is instructed that the transmission should be shifted to the 10th gear for reengagement of the clutch, and this operation is executed. The special method of when to execute this procedure will be further described with reference to the flowcharts of FIG.

The transmission control system 90 operates the drive system 50 in a normal operating mode known as the "pulsar" mode and three new operating modes known as the "ground speed" (GS) mode. To do. The simplest of the three GS modes is the "comfort" mode, which keeps the actual ground speed as close as possible to the operator-selected desired ground speed, while at the same time allowing the engine speed to respond to variable loads. To reduce the number of transmission shifts. The other two GS modes are the "max horsepower" GS mode and the "fuel save" mode, which modes are briefly described.

In the pulsar mode, the operator selects the desired gear and the desired throttle speed of the engine. This is done using transmission shift lever 242 and engine throttle lever 100. After selecting the pulser mode with the changeover switch 226, the operator uses the shift lever 242 to select the desired gear that he / she wants to operate. Then (or before) also select the desired engine speed. Once the gear and engine speed are known, the ground speed can be calculated taking into account the wheel slippage, so selecting a gear and a specific engine speed would effectively mean selecting the ground speed. Would be obvious. In pulsar mode, the selected transmission gear is not automatically changed, instead it stays in the same gear when the engine lugs down significantly.

FIG. 7 is a diagram illustrating three new modes of operating or operating an engine-transmission combination, which modes are referred to as ground speed (GS) mode or "variable ground speed" (VGS) mode. The term "variable" is used because the controller 302 can change the vehicle ground speed by adjusting the engine speed command (independent of lever 100 and pot 280, by signal 402). As will be described later, the throttle lever 100 acts as a master regulator or governor and the controller 302
Limits the maximum engine speed that can be tolerated.

The control system 60 also has another operating mode, the normal mode known as the "pulsar" mode. The basic mode of operating the control system 90 with either the GS or the pulsar is selected by the changeover switch 226 shown in the block diagram of FIG. Here, the pulsar mode will be briefly described. Once the gear and engine speed are known, the ground speed can be calculated considering the wheel slip, so selecting the gear and a specific throttle speed is virtually the same as selecting the ground speed. Those skilled in the art will understand that. In pulsar mode operation, the tractor travels in a gear at a substantially fixed rotational speed (constant engine speed) (both gear and rotational speed are operator selected). If the pulsar mode operation is not possible due to excessive load on the engine due to load on the off-road vehicle or ground conditions, the transmission will remain in the operator selected gear and the engine will lag down. Or even stall.

Both new ground speed modes are clearly different from the pulsar mode. In either GS mode, neither the transmission gear nor the engine speed is fixed, allowing other parameters or conditions in the engine / transmission combination to vary as necessary to maintain at or near the desired state. There is. In the present invention, there are three parameters or conditions that can be selected as very important and these are kept at or near the desired state. This holding is performed by the power mode selector switch 224 shown in FIG. 2, and the power mode selector switch 224 has three positions, namely,
Comfortable, maximum horsepower, fuel saving. When the switch 224 is in the comfort mode and the drive mode switch 226 is in the GS position, the control system 90 changes the engine speed or, if necessary, the selected gear to maintain the desired ground speed, thereby causing the tractor to reach a constant ground. Try to keep on speed. The ground speed range for the engine (the engine operates in the range of this speed band regardless of which gear is shifted) is shown in the speed region of the combination of white and shaded squares for each gear shown in FIG.

When the changeover switch 224 is in the "maximum horsepower" position and the changeover switch 226 is in the "GS" position, the control system 90 uses engine speeds and gears to produce effective maximum horsepower for the job. / Try to maintain the desired ground speed while driving the transmission combination. The ground speed range for the drive system (the drive system 50 operates in this speed range regardless of which gear is shifted) is shown in FIG. 7 by the outline square of each gear. One of ordinary skill in the art should understand that this method of operating the control system 60 allows maximum horsepower to be drawn from the drive system 50 of an off-road vehicle. In this operating mode, the engine speed and, if necessary, the selected gear are also changed. Also, when the control system 60 is so heavy that it has to shift to a lower gear, the ground speed may vary somewhat to accommodate the load experienced by the vehicle and / or the high load exerted on the drive system by the ground. I have something to do.

When changeover switch 224 is in the "fuel save" position and changeover switch 226 is in the GS position, control system 90 operates drive 50 to minimize fuel consumption. This operation mode is effective when an off-road vehicle such as a tractor exerts only a comparatively light load and is used for a work in which an appropriate low speed is required to be maintained. The control system 90 selects gears and engine speed to maximize fuel economy.
Regardless of what ground speed is set, the above selection can be performed by operating the drive system 50 in the gear designated by the shaded square in FIG. The fuel saving GS mode generally results in the selection of a relatively high transmission gear, and thus the engine is run at a lower RPM than when the maximum horsepower operating mode is selected.
As in maximum horsepower mode, control system 60
May not be able to both optimize fuel economy and maintain desired engine speed at the same time. In that case, the control system 90 is programmed to the comfort mode, downshifting and increasing RPM to automatically maintain ground speed. The deviation from the optimum gear and engine speed is
If necessary, it is displayed on the dashboard 92.

In summary, under most conditions in any of the GS operating modes, it is possible to operate the vehicle at a fairly uniform operating speed even with the same gear. However, if the grade, type of ground, or load changes so much that the desired speed cannot be maintained, the control system 90 automatically adjusts the engine throttle as needed and also upshifts or downshifts the transmission, Make the actual ground speed as close as possible to the desired ground speed.
To do this in either GS mode, system 90 modifies the desired engine speed signal provided to engine controller 54 as needed to maintain desired ground speed. If increasing the desired engine speed signal to its maximum allowed value does not actually increase the ground speed (which can occur when the engine is lagging down or overloaded), the system 90 shifts down the transmission 64 to obtain greater overshift power on the driven wheels of the vehicle. Operating the tractor in a highly automated manner can be very effective in reducing operator fatigue, especially when the operator holds the steering wheel for hours. Only highly trained and skilled operators are likely to be able to continue driving off-road vehicles for extended periods of time with maximum fuel economy or maximum horsepower. Therefore, the above two GS
Both modes of operation are considered to be extremely useful. For example, one day of operation in fuel economy mode can save a considerable amount of fuel. Similarly, if the operation is performed in the maximum horsepower mode, the farmer can complete the cultivation of the cultivated land in the minimum time even when the rainstorm approaches. Comfort mode is useful when working in situations where the demands on off-road vehicles are quite variable and where frequent automatic shifts are undesirable. For example, a farmer who cultivates loose hills or arable land with changing soil may not want to frequently change gears on the tractor. In comfort mode, the gears of the transmission can be used over a wider range of engine speeds, thus considerably reducing the number of shifts required, thus eliminating the need for frequent gear shifts. This makes the ride more smooth and therefore more comfortable for the operator. In addition, the transmission and its accessories receive a more stable tensile force, which helps reduce wear and wear.

The GS operation mode is entered as follows:
It is preferably operated. First, the operator turns the changeover switch 226 to the GS position to change the changeover switch 22.
Select power mode for maximum horsepower, comfort or fuel savings by 4. The operator then uses the shift lever 242 to dial the desired ground speed on the display 204 of the dashboard console 92. The number on the display unit 204 automatically increases as long as the shift lever is held in the up position, and decreases as long as the shift lever is held in the down position. When the displayed number reaches the desired ground speed, the operator releases the spring type shift lever 242, and the shift lever 242 returns to the center position. The control system 90 uses the desired ground speed and power mode selection to determine which gear and engine speed to drive the vehicle. Next, the operator turns the direction lever 2
When the clutch pedal 112 is released with 32 in the forward position, the vehicle starts moving forward in the first gear. The engine speed is the throttle lever 10 until the clutch pedal is completely released (full release is determined by activating the top switch 274 of the clutch pedal 112).
It remains at the number of revolutions selected by 0. The maximum allowable engine speed in any operating mode (pulsar or ground speed) is determined by the pot 280. Normally, the operator wants the vehicle to reach the desired speed quickly, so move the throttle lever 100 to the maximum rpm setting and leave it there. Once this is done,
The control system 90 immediately adjusts the desired engine speed signal to accelerate the vehicle in successive gear shifts until the desired ground speed is reached. If throttle lever 1
When 00 is set below the full power (100%) setting, for example at the 95% setting, control system 90 operates normally, as determined by the graph of FIG.
However, the maximum actual operating speed cannot exceed the above 95% value.

The control system 90 stores the automatic shift points in its reprogrammable non-volatile memory 312. Examples of typical shift points are shown in Tables 1 and 2 below. Table 1 shows the automatic shift points used when the changeover switch 224 is in the maximum horsepower position and the operation mode changeover switch 226 is in the GS position.

[0070]

[Table 1]

Table 2 shows the automatic shift points used by the control system 90 when the selector switch 224 is in the fuel saving position and the operating mode selector switch 226 is in the GS position.

[0072]

[Table 2]

The values in Tables 1 and 2 generally correspond to the data points in the graph of FIG. However, there is some variation and Tables 1 and 2 better represent the shift points used in the prototype system of the present invention. Note in Tables 1 and 2 that for each gear there is an overlap between the upshift and downshift speeds.

FIG. 8 is a shift map, that is, a map of automatic shift-up points and shift-down points for each forward gear. The control system 90 preferably uses these points when the changeover switch 226 is in ground speed mode and the changeover switch 224 is in the comfortable position. In this condition, the main function of the control system is to automatically increase or decrease the desired engine speed to maintain the actual ground speed at or near the desired ground speed, and if desired, the desired engine speed sent to the engine controller 54. It is also possible to shift to another gear with as many additional changes as necessary in a few commands (the shift points in Tables 1 and 2 are shown in FIG.
It is also possible to represent in a graph format such as the shift map).

The shift points shown in FIG. 8 reduce the number of shifts required when a hilly area or the drive system 50 is subjected to an irregular load, and maximize the smoothness of the shift in the prototype drive system 60 of the present invention. Was chosen to be. The shift points are adjusted to reduce gear impact, especially when multiple clutch devices are engaged. For example, as shown in FIG. 3, when shifting from the forward gear 6 to the forward gear 7, the solenoids W, T, and S are used to shift three gears.
Disengaging the individual clutch devices to cause the solenoids Z, V,
It is necessary for Q to engage the other three clutch devices. Since the hydraulic supply system in the transmission has a limited capacity, additional time is required to produce such a shift. Similarly, for shifting between the gears 3 and 4, and between the gears 9 and 10, as shown in FIG.
Engagement of a number of additional clutch devices is required. In either case, the clutch device requires additional time to shift, and it is preferable not to do such a shift until needed. For this reason, the shift-up points of the forward gears 3, 6, 9 are set higher (than in the normal case) compared with the case where there is no such situation. Special shift-up and shift-down points that minimize shaking and impacts can be made by experimenting or simply by changing the points during a test drive of the vehicle, or by trial and error by judging the results by feeling. Can be determined by
Since the automatic shift points are stored in a reprogrammable non-volatile memory, those skilled in the art can easily carry out such experiments until an appropriately smooth shift pattern is obtained. Using a similar approach helps to modify the shift points in Tables 1 and 2 to facilitate the shifting procedure.

9 and 10 show throttle maps of the gears 1 to 6 and the gears 7 to 12, respectively. Figure 9
Then, the horizontal axis represents the desired ground speed in mph, and the vertical axis represents the required percent throttle as a percentage of the allowable range (10% -80%) of the VREF signal. In other words, FIG.
0% and 100% on the vertical axis of FIG. 5 correspond to 10% and 80% on the vertical axis of FIG. 5, respectively. This graph or map shows what engine speed command signal (described above with reference to FIG. 5) should be sent for the desired ground speed value once the gear is determined. The map of FIG. 10 provides the same information regarding the desired engine speed command signal for gears 7-12. The graphs shown in FIGS. 9 and 10 assume no wheel slippage and no engine performance droop.

The throttle map information shown in FIGS. 9 and 10 is used by the controller 90 when the changeover switch 226 is at the ground speed position. Used by the control system, in particular in determining what engine speed should be requested from the engine controller 54 (information in Table 1 or Table 2 or FIG. 8 is used to determine in which gear the transmission should be shifted. ). Since the graph is a straight line, this information can be easily stored in mathematical or tabular form. The usage of the information stored in any format is within the technical scope of those skilled in the art, and the description thereof is omitted here.

Software of Control System 90 Next, the internal operation of the electronic control system 90 shown in FIG.
11 to 27, description will be given from the viewpoint of software and programming. In the software flow chart,
First, the pulsar transmission control sequence will be described with reference to the flowcharts and FIGS. 11 to 19. next,
20 to 24, a variable ground speed control mode,
That is, the comfortable mode, the maximum horsepower mode, and the fuel saving mode will be described. Finally, FIGS. 25 to 27 describe a pseudo gear control mode in which the drive train is considered to have more transmission gears than are actually present.

When the power is turned on, the controllers 301 and 3
Each of the 02 microprocessors initializes the internal registers, services the watchdog timer, checks the integrity of the stored program by a checksum procedure, initializes the diagnostic code, and other routines for starting the microprocessor. Performs conventional startup routines, including procedure execution.

FIG. 11 shows a software main loop that is repeatedly executed by the controller 301. When the power-on routine is completed, start point 4 of the main loop
Enter 50. Initially, external and internal watchdog timers are serviced, as indicated by action block 452. Next, the analog / digital conversion routine 45
4 is executed, and the value of any analog input supplied to the controller 301 is acquired by the analog input circuit 318 shown in FIG.

The controller 301 uses various internal timers that can be either real-time interrupt generation hardware timers or software clocks attached to the microcontroller 301. (It will be appreciated by those skilled in the art that with properly designed and tested fast executing software code, the software timer will be very accurate and suitable for real time process control.) Internal timer used in controller 301 Is a 4.096 ms timer (about 4 ms), 16.
Includes a 384 millisecond (about 16 millisecond) timer, a 524 millisecond timer, and a 1048 millisecond timer. For simplicity, the former two timers are usually referred to below as the 4 ms timer and the 16 ms timer. Similarly,
“Milliseconds” may be abbreviated as “MS”.

In FIG. 11, decision block 456 determines if a frequency input transition has occurred. This is determined by examining the interrupt generated by the signal transition detected at input circuit 324 (see FIG. 4). The interrupt code obtains the instantaneous value of the microprocessor's fast real-time clock by having its own memory location in RAM for each frequency input to store the instantaneous value. If an interrupt occurs, proceed to block 458. Here, the obtained instantaneous value is processed by a conventional averaging routine that helps the filter transient determine the condition represented by the actual speed or RPM value of its analog input. These calculations are
It is based on the known inverse relationship between the period and frequency of the pulsating signal, such as the type produced by a variable reluctance sensor.
Once such speed (RPM) values are determined, they are stored in different locations in RAM for use by other routines.

After that, the process proceeds to the negative route 462 connected to the decision block 466. At block 466, it is determined whether the 4 millisecond internal timer described above has expired. If it has, routine 470, the 4 millisecond loop shift control routine, is executed. This will be described later with reference to FIGS. 12 and 13. Thereafter, block 466 transfers to the negative path 472 which leads to a decision block 474 which asks whether the above 16 ms internal timer has expired. If the judgment result is affirmative,
After executing the 16 millisecond timer routine shown in FIG. 14 at block 476, the dashboard communication routine 480.
Move to. The routine 480 is the display device 9 shown in FIG.
2, and the internal controller 190 of the display device 92 will immediately display.

Thereafter, at block 482, the digital switch input values are checked and debounced, thereby causing the input 316 of the controller 301 to be checked.
Establishes the conformance state of any digital input received via. Meanwhile, the controller 302 can transmit various process data such as the current value of the throttle position output collected from the potentiometer 280 (see FIG. 4) to the controller 301. As shown in FIG. 11, block 484 transfers such process data from controller 302 (referred to as “frame 2” in software) to controller 301 (referred to as “frame 1” in software) via SPI communication path 344. Called).

At block 486, various housekeeping performed by the controller 301 is performed, such as recalibration of itself with a DC reference value so that the analog value is read correctly when block 454 is performed after a few microseconds. It Routine 486 also returns E
The integrity of the system parameter information stored in the EPROM 312 is also checked (checked). These information are the RPM points of the upper power band and the RP of the lower power band in FIG.
Information can be included about the engine, such as the M point, and solenoid shift times associated with transitions from one gear to another. Finally, at step 488, the microprocessor performs other conventional checks to ensure software integrity and controller configuration. These include refreshing the data direction of the I / O ports and the time values from the EEPROM currently stored in RAM, as well as transient values not reconfiguring part of the memory in an undesired way. To assure, it includes checking significant parts of the code with checksums and other error detection methods. It then moves to the main loop start point 450 of FIG. 11 to re-execute the entire main loop, as illustrated by the connector 500.

12 and 13 are flow charts illustrating the technique used to control gear changes in the power shift transmission 64. As described above, in order to change from one gear to another, as shown in FIG. 3, demagnetization of 1 to 3 solenoids and 1 to 3 solenoids are performed.
Excitation of individual solenoids is required. As is known in the art, the smoothness of shifting between gears in a transmission can be improved if the required demagnetization and excitation of the actuated solenoids is done in a particular timing sequence. For example, to prevent momentary freewheeling of the transmission, another clutch device to be engaged is already engaged before one clutch device is completely disengaged (disengaged). It is effective to do so. This minimizes gear lash during shifting. Such control of demagnetization and energization of valve and clutch devices to minimize rattling and improve shifting is well known in the transmission art and is therefore no further consideration in terms of mechanical or timing. No need to explain. Instead, a preferred method for performing such a transmission shift under software control by the microprocessor will be described with reference to FIGS.

Upon entering the shift control routine at start point 510, controller 301 first determines if a 1.5 second power up delay has been completed by decision block 51.
Check at 2. This delay helps stabilize the mechanical and electrical conditions of the engine / transmission control system 60 at power up before the control system 90 directs any physical operation. If this delay is not complete, the negative path 514 leads to the connector labeled "Shift 999" which leads to the end point 516 of the shift routine shown at the bottom of FIG.

Upon completion of the power-on delay, block 51
Proceed from 2 to the positive route (YES route). Thereafter, decision block 520 determines if clutch pedal 112 (see FIG. 2) has been fully released, as indicated by switch 274 being actuated and switch 272 being released. If the determination is negative, the controller 301 checks the current vehicle speed (determined at block 458 of FIG. 11) and uses that value to match the predetermined vehicle speed and engine speed at block 570. Calculate the search value X to access the ground speed matching data table, which specifies the correct gear required for the ground speed. How to use such a table has already been described with reference to FIG. 6, and will be omitted here. At blocks 572 and 574, the current gear and the demand gear are set to the gear designated at the position indicated by the value X in the look-up table. Then, the connector 528 moves to the connector 530 of FIG.

At decision block 540 of FIG. 13, it is determined whether the current gear is in either forward or reverse first speed. The determination result is affirmative, and further, the determination block 5
If the clutch pedal is not fully depressed according to the determination at 42, path 546 causes motion block 54
Move to 8. In this block 548, the solenoid required for the first speed forward or the first speed reverse is excited based on the selected direction. If the clutch pedal is fully depressed according to the determination in the determination block 542, the process proceeds to the determination block 552 for inspecting the vehicle speed by the positive route. If the vehicle speed is zero, affirmative path 554 transitions to action block 556. Block 556
The solenoids V and T are then energized to prevent shaft freewheeling in the transmission 64 which can occur if the transmission is in neutral due to viscous coupling. Solenoid V
By energizing T and T, the transmission 64
Is held neutral, but the freewheeling is stopped by engaging the intermediate shaft and the clutch device. However, do not stop the input shaft or output shaft. Failure to stop such freewheeling will often result in noise when the transmission is later reengaged. If it is determined in block 552 that the vehicle speed is not zero, the operation moves to operation block 548, and the solenoid is moved forward or backward based on which direction is selected (see the check in the determination block 540 described above). It is operated for 1st speed.

In FIG. 13, the result of the decision block 540 may be NO, which indicates that the current gear selected by the result of the look-up from the block 572 (FIG. 12) is not the first forward or reverse speed. possible. In that case, the process proceeds to block 562 for turning off the solenoid. This latter operation is performed by the decision block 56 in FIG.
At 2, the clutch pedal was not completely released and it was determined a few microseconds ago. To avoid heat dissipation problems in the transmission that can occur if the master mechanical clutch is only partially engaged, all solenoids are turned off, which disengages the transmission from the gear, Allows coasting of the vehicle. After that, the process proceeds to the end point 516 of the shift routine.

The 4 millisecond loop shift control routine shown in FIG. 12 is executed every 4 milliseconds. At some point, the clutch pedal will be fully released. At that time, the positive path of decision block 520 is taken,
At block 522, the shift timer is incremented. Next, at decision block 580, a check is made to see if the current gear is the required gear. Since the ground speed matching routine is modifying both the current gear and the demand gear, the current gear should equal the demand gear and the solenoid for that gear is turned on at action block 582. In other words, releasing the clutch pedal puts the transmission into a gear that most closely matches the ratio of vehicle speed and engine speed. At some point, the current gear may not be equal to the required gear, which means that the operator has selected a gear different from the gear that the transmission is currently in. If so, decision block 580
Then, the process proceeds to the decision block 586, and it is determined whether or not the requested gear is lower than the current gear. If the determination is affirmative, the memory is retrieved for information regarding the next downshift.
Information about downshifts includes information about which solenoid state changes and at what shift time or point the change occurs for a particular downshift requested (excitation or The shift time of each demagnetized solenoid is stored in EPROM as a number representing the elapsed time from the start of shift to the shift point.) This action is represented by block 588. If an upshift is required, block 590 is entered and similarly the solenoid state change and the shift timing for the particular upshift found is loaded. After that, "Shift 200"
The action block 592 of FIG.
Move to. In this block, that particular shift time value is checked against the current shift time value, and after each particular shift point time, that particular select solenoid is either turned on or off as required as part of the continuous shift sequence. Be put into a state. At decision block 594,
It is checked whether the entire shift time has been completed. If the determination result is negative, the process moves to the end point 516, and the shift control loop is reexecuted after 4 milliseconds. Finally, when the shift control routine is repeatedly executed, the decision block 59 of FIG.
The result of 4 is YES. Then set the current gear to the new gear, as shown in blocks 596 and 598,
The shift timer is cleared. The new gear here is
A new gear in the transmission that is switched by the shift sequence just completed.

FIG. 14 shows a 16 millisecond timer routine. The first step performed at block 600 is a “1
1 counter for "6MS free running timer"
Only to increment. Next, at block 602, any changes to parameters or other values that need to be permanently stored in non-volatile memory (EEPROM) are made. At block 604, the value of the 16MS free running timer is divided by 64 and a check decision is made to see if the remainder is zero. If the determination is affirmative, 1048 milliseconds have elapsed since the remainder was last zero, and block 606 performs frequency input diagnostics. These diagnostics are known because the transmission gear ratio and the actual engine speed are known. A check is also made to see if the indicator is working properly. If either sensor indicates an out-of-range indication,
The error state mode is activated, driveline 50 can function in a limited manner without giving suspicious instructions, and an error code indicating the same instruction is generated and displayed on dashboard 92. For example, if the ground speed sensor fails, the actual ground speed is calculated from the product of the current transmission gear ratio x the actual speed x the tire diameter x an appropriate scaling factor. It is considered that the performance of the drive system 50 is limited because the ground speed is derived from indirect measurements rather than actual measurements.

Thereafter, the process proceeds to the decision block 608 and 1
A test decision is made to divide the 6MS timer value by 32 to see if the remainder is zero. If the determination is affirmative, then approximately 524 milliseconds have elapsed since the remainder was last zero, and as shown in block 610,
System voltage is monitored. If it is determined that the vehicle supply voltage is too low, a warning message is displayed on the dashboard 92.
To alert the operator of possible problems (the transmission solenoid may not energize properly under extremely low supply voltage conditions).

As shown in FIG. 14, a decision block 614 is then entered to check to determine if the operator input has switched from the settings 94 and 96 shown in FIG. The mode control routine 616 is executed only once upon detection of a valid change of state on either switch. That is, the mode control routine is entered only when the command switch, which is operator controlled and forms part of the operator interface, changes state in some way. Thereafter, the route 618 moves to the frequency input dropout routine 620. This routine calculates the frequency of any one of the frequency inputs received by the frequency input circuit 324 (see FIG. 4) f = 1 /
It is determined whether or not T (where f is a frequency and T is a measurement period) is low enough to cause an overflow condition.
This condition corresponds to the detection of a velocity very close to zero and the result is the RA reserved for such frequency input values.
Recorded as zero in M memory locations.

Next, the sequential shifting routine 622 is executed. Basically, this routine is responsible for performing the multi-shift that results from leaving the upshift or downshift switch energized. In particular, these multi-shifts are performed in a predetermined amount of time per gear, similar to a single gear shift, by specifying a predetermined minimum time this routine takes between shifts. The operation of this routine will be described in detail with reference to FIG.

Referring next to FIG. 14, a solenoid / driver diagnostic routine 624 is shown. This routine uses output circuits 332 and 334 in a manner known in the art.
Measures the current supplied to the solenoid by. Specifically, the current level of the solenoid driver circuit is checked to effectively ensure that there are no shorts or opens. Next, at block 626, controller 3
Motorola MC used in 01 and 302
A Synchronous Peripheral Interface (SPI) port that is part of the 68HC11 series microprocessor initiates the transfer of information from controller 301 to controller 302. Finally, the end point 628 of the 16MS timer routine is reached and the process returns to the main routine of FIG.

FIG. 15 shows a mode control routine 616 that is called by and forms part of the 16MS timer routine of FIG. The mode control routine 616 responds only once to a transition to the state of a given switch. If the flow goes through the mode control routine 616 again, it does not cause any further action if the switch remains in the same state. In this regard, the mode control routine 616 may be said to be transition driven rather than switch state driven.
The routine 616 checks the status of the operator interface switch set 94 and other switches shown in FIG. 2 to establish the correct mode in which the control system 90 should operate. Note that this control code resides on controller 301, which acts as the master controller for control system 90.

The mode control routine 616 first tests the state of the neutral switch 238 of the directional lever 232. If the switch is on, "Mode control 9
15 through 16 to the bottom entry point 634 of FIG. 16 via a connector 632 marked "995". Thereafter, at action block 636, the mode state is set to neutral and all transmission solenoids are turned off. Next, the end point 64 of the mode control routine 616.
It reaches 0 and returns to the route 618 of FIG.

Returning to the top of FIG. 15, if the neutral switch is not turned on, the process proceeds to the decision block 644 by the negative path 642. This block 644
Now check the 0.5 second power up delay timer described above with respect to decision block 512 of FIG. If the power-up delay is complete, decision block 646 checks the state of all debounced switches to determine if there is a valid combination of switch states. If not, the system will exit block 63.
After 2, the operation block 636 shown at the bottom of FIG. If the switch states represent a valid combination, the transition of the down switch 250 of the switch lever 242 is checked by decision block 650. If the down switch 250 has been activated, block 652 clears the sequential shift timer (described below with reference to FIG. 17). If the down switch is not actuated, then path 656 leads to decision block 658 and switch lever 242 (see FIG. 2).
Inspect up switch 246 of. Up switch 2
If 46 is present, block 660 clears the sequential shift timer and proceeds to decision block 662. If the up switch 246 is not turned on, it will go through the connector 664 labeled "mode control 1900" in FIG.
The decision block 666 at the top of 6 is entered.

The decision block 672 is a forward switch 236.
(See FIG. 2). If the directional lever 232 is in the forward position, the switch is activated and moves to decision block 674. If it is not in the forward position, the method moves to decision block 676 and tests the reverse switch 240 to determine if the directional lever 232 is in the reverse position. If the determination result is affirmative, the process moves to a decision block 678, and if the result is negative, the control mode state is entered.

Returning to FIG. 15, description continues with positive path 684 of decision block 654 which is executed when the clutch is fully released. Decision block 686 tests to determine if the vehicle is moving in reverse. If you are moving backwards,
Since the down switch is operating according to the determination by the determination block 650 to reach the block 686, the requested gear is the first reverse gear. Therefore, block 688
As shown in, the required gear is set to the first reverse gear. If the direction lever 232 is in the forward position, the decision block 690 starts the shift down routine 692 (see FIG. 18).
Will be described in detail later). When advancing from decision block 690 to negative path 694, directional lever 232 is in the neutral position. Regardless of whether the vehicle is moving forward, it finally moves to decision block 658, and if the up switch is not turned on, decision block 67 of FIG.
Go to 2 and 674. If it is determined at decision block 674 that the vehicle is stationary or is moving forward or slow reverse, the controller 301 sets the requested gear to the downshift routine of FIG. The forward gear that is required according to the determination in the shift-up routine of FIG. 19 is made equal. Similarly, if the reverse switch is turned on at decision block 676, and further if it is determined at decision block 678 that the vehicle is stationary, or is moving backward or at a low speed, then the affirmative route of decision block 678. There is no problem even if the transmission is shifted to the required reverse gear instructed through block 698 after passing through. Both paths lead to the end point 640 of the mode control at the bottom of FIG.

Decision block 662 at the bottom of FIG. 15 determines if the clutch is fully released. If the determination result is affirmative, the process proceeds to the determination block 702 in FIG. 16 via the connector 700 marked as “mode control 1805”. At decision block 702, it is determined whether the vehicle is moving backward. If the determination result is affirmative, since the up switch is turned on as determined in the determination block 658, the required gear is set equal to the second reverse gear in the block 704. Then, decision blocks 672, 6
The end point 640 is reached via 76 and 678 and block 698.

If the vehicle is not moving in reverse at decision block 702, then control is passed to decision block 706 which asks if the vehicle is moving forward, as determined by monitoring directional lever 232 (see FIG. 2). If the determination result is affirmative, the up switch is turned on as determined in the determination block 658 in FIG. 15, and therefore the shift up subroutine 708 detailed in FIG. 19 is entered. After this is done, via decision blocks 672 and 674, FIG.
To the end point 640 of the mode control at the bottom of the.

FIG. 17 illustrates the Sequential Shift Routine 622 which is accessed from the 16MS Timer Routine referred to as Block 622 in FIG. The routine 622 first makes an inspection decision at decision block 720 as to whether the vehicle direction lever 232 is forward. If the answer is yes, decision block 722 tests to determine if either up switch 244 or down switch 250 is on. If the judgment result is affirmative,
The decision block 724 checks to see if the clutch is released. If the answer is yes, decision block 726 tests to determine if the current gear is higher than first gear. If the answers to all four questions made by decision blocks 720-726 are positive, then the sequential shift timer is incremented as shown in block 730. Any one of the questions in decision blocks 720-726
If any response is negative, path 732 leads to block 734 and the sequential shift timer is cleared. After that, the sequence shifts to the end point 326 of the sequential shift routine and returns to the right corner portion of FIG.

At decision block 740, the current value of the sequential shift timer is compared to the total sequence shift time established for the particular shift being performed. If this entire sequence shift time has elapsed, the process proceeds to a decision block 742, and the state of the down switch 250, and thus the state of the shift lever 242 is inspected. If the down switch is on, the downshift subroutine 748 is called. If not, the upshift subroutine 750 is called. These subroutines are shown in FIGS. 18 and 19, respectively. After the appropriate subroutines have been executed, the sequential shift timer is cleared at block 734 and the sequential shift routine end point 736 is reached.

FIG. 18 shows the downshift subroutine called by block 692 of FIG. 15 and block 748 of FIG. The downshift subroutine first determines at block 760 whether the requested gear is higher than first speed. If the determination result is negative, the requested gear has already been set to the first speed and no operation is required.
Therefore, the transition is made to the exit point 762. If the requested gear is higher than first gear, block 762 decrements the requested gear by one. After that, the process moves to the subroutine exit 762.

FIG. 19 shows the upshift subroutine called by block 708 of FIG. 16 and block 750 of FIG. Decision block 770 determines whether the requested gear is less than the 12th speed. If the determination result is negative, it indicates that the required gear is the 12th speed, which is the maximum gear value, and the process moves to the exit point 772. If the requested gear is less than the 12th speed, block 77
4 increments the required gear by 1 and then moves to the subroutine exit point 772.

20 and 21 show a control system 90.
The functional operation of the software used by the controller 302 in the case of operating in the normal pulser mode will be described. The software of the controller 302 uses most of the software of the controller 302,
To the extent there are such common uses of software code, the description will not be repeated. Only those differences will be explained below.

Like controller 301, controller 302 includes a main loop similar in overall configuration to the main loop shown in FIG. The controller 302 is
It does not need a 4 millisecond timer 466 at all and uses only a 16 millisecond internal timer. Action block 800 services the watchdog timer. The A / D conversion routine 801 services the A / D conversion circuits to their range of use (see FIG. 4, which illustrates monitoring the analog VREF signal and the analog throttle position signal from potentiometer 280). Next, at decision block 802, a test determination is made as to whether the 16.384 millisecond internal timer of controller 302 has expired. If the determination result is affirmative, FIG.
The 16 millisecond timer routine 804 shown in 1 is executed. After that, the process proceeds to the switch input detection / debounce block 805, the blocks 806 to 810 are sequentially executed, and finally the main loop returns and the connector 81 is executed.
20. Return to the starting point marked "main loop 000" in FIG.

Block 806 checks if a message was received from controller 301 through SPI port 388. Block 807 checks for external serial communication over port 389. Block 808
Perform a calibration and verification routine for the same purpose as described with respect to block 486 of FIG.
Microprocessor diagnostics are performed for the reasons described with respect to block 488 of FIG.

FIG. 21 shows the 16 millisecond timer routine 804 described in FIG. In the figure, block 820 is 1
Increment 6ms free running timer, block 8
22 performs any necessary EEPROM programming of controller 302, which is performed for the same basic reasons as described for block 602 of FIG.

Next, decision block 826 determines if another 524
A check decision is made to see if a millisecond (about 0.5 second) time interval has begun. If the determination result is affirmative, then FIG.
4. Block 828 is executed to monitor the system voltage for the same reason as described for block 602 of FIG. 4 (similar to the 16MS timer routine shown in FIG. 14, this routine of FIG. (Note that we find the beginning of such long intervals by computing the longer intervals by dividing by a number such as 32 or 4 and seeing if the remainder is zero.).

At the beginning of each 66 millisecond interval, the affirmative path of decision block 830 transitions to dotted block 831 which corresponds to the 66MS timer routine. Routine 8
Block 832 of 31 reads the desired throttle position sensor (TPS), ie pot 280, as the voltage supplied to the analog input circuit 368 of the controller 302. Block 834 is a determination of the allowable stroke of the pot 280, which is determined by comparing the obtained value with predetermined maximum and minimum values that represent a fully advanced and fully reverse throttle lever condition. Simply calculate the digitized analog value received as a percentage of the full range. At block 836, the calculated result from block 834, the throttle output percentage (TPS%), is converted to a digital rotational speed command signal by adjusting it with gain and offset values. Thereafter, in block 838, the software and hardware are combined to produce the voltage value VR read by the analog input circuit 368 of FIG.
The D / A converter 400 shown in FIG. 4 as a function of EF.
Supply the output value to. This digital value just calculated (throttle output%) is then written to D / A converter 400 through digital output port 386. As a result, the 16MS timer routine 80 of FIG.
4 is complete.

22 and 23 illustrate the modifications required to the software used in controller 301 to implement any one of the variable ground speed modes of the present invention. 22 illustrates a modified 4 millisecond shift control routine, and FIG. 23 illustrates a modified mode control routine. Figure 2
The software routine shown in FIG. 2 complements the software control routine described with reference to FIGS. 12 and 13, and the software routine shown in FIG. 23 has the same name as the software routine described with reference to FIGS. It is a simplified representation of the wear routine.

FIG. 22 replaces block 470 of FIG. The decision block 850 determines whether or not the traveling mode switch 226 (see FIG. 2) is in the ground speed position. If the result of the judgment is negative, the selector switch 226 should be in the position of the pulser switch, which means that the control system 90 is not in the ground speed position. Thus, if the answer to the question made by decision block 850 is no, then path 852 goes to the bottom of FIG. To be done. When that routine is completed, the process moves to exit point 854 and ends.

If the answer to the question posed by decision block 850 is affirmative, then control transfers to decision block 860 which asks if a transmission shift is in progress. If the value of the shift timer (see block 598 in FIG. 13) is non-zero, the shift is in progress and path 8
A shift to the bottom of FIG. Then, the shift control routine (block 470) is executed. That is, if transmission shifting is in progress, the transmission controller 301 proceeds with the procedure for successfully completing the shift before performing any additional action, as determined in block 860.

If the answer to decision block 860 is no, then block 872 is reached. Here, a variable parameter called "maximum shift speed" is set to a value proportional to the difference between the desired ground speed and the actual ground speed. The maximum shift speed is used to determine when it is possible for the transmission to shift from one gear to the next. The greater the difference between the desired ground speed and the actual ground speed, the faster the transmission can shift. This fast shifting is done by reducing the delay time between successive shifts. Therefore, when the actual speed of the vehicle approaches the desired speed,
Transmission is 1 before the start of the next shift
You will have to wait a long time after completing one shift. This long delay time between shifts causes the controller 302, operating in closed loop feedback mode, to vary the value of the engine speed command signal sent to the engine to account for the error between the desired ground speed and the actual ground speed. Have the opportunity to reduce. If the engine speed is changed in a given gear, the vehicle speed will change in the same direction. Therefore, increasing the delay between gear shifts helps avoid overshoot and hunting as the ground speed error value is reduced. The maximum shift speed is set equal to the absolute value determined by the difference between the desired / user selected speed and the actual speed times the gain value. Appropriate gain values may be empirically determined during testing for any given engine / transmission combination.

Referring now to FIG. 22, block 874 increments the shift delay timer and proceeds to decision block 876.
At decision block 876, it is determined if the shift delay timer has a value greater than the maximum shift speed value. If the determination result is negative, the process moves to the bottom of the figure by the route 852 so that no further shift is performed. If the answer in decision block 876 is positive, upshifting or downshifting is possible to reduce the absolute value of the ground speed error. That is, decision block 876 determines if the gear has had sufficient time to stabilize since the last shift. Decision block 876 effectively determines a minimum value between gear shifts.

Thereafter, the process proceeds to a decision block 880, and it is determined whether or not the current gear is higher than the first speed. If not, then no downshift is required and the decision block 862 is entered. If the current gear is higher than first gear, downshifting may be required. At block 884, the controller 301 looks up (table index) to determine the downshift speed based on the current gear.
To execute. If the current ground speed is less than the indexed downshift speed, decision blocks 886 through 88.
Go to 8. Therefore, the required gear is set to be equal to (current gear-1), and the route 870 shifts to the bottom of FIG.

If it is determined at decision block 886 that downshifting is required, decision block 862 is entered. At decision block 862, it is determined whether or not the current gear is lower than the highest gear, that is, the twelfth speed gear. If the determination result is negative, the transmission 64 is the 12th
It is in a high speed gear and it is impossible to shift up. In this case, the process proceeds to the lowest block 470 in FIG. 22 via the negative route 870. If the current gear is lower than the highest gear, decision block 862 transfers to decision block 885. Here, the controller 301 determines whether or not the current gear is the optimum gear for the desired speed. The determination result here depends on the setting of the power mode switch. As described in FIG. 2, this switch has three types of settings: maximum horsepower mode, comfort mode and fuel saving mode.

At decision block 885, when switch 224 is in the comfort mode position, the current gear is illustrated in FIG. 7 as long as the vehicle speed is within the range defined by the sum of the outlined and shaded blocks in FIG. The desired current gear is considered as the optimum gear. Alternatively, if the vehicle speed is within the range between the shift up point and the shift down point in FIG. 8, the current gear is regarded as the optimum gear.

At decision block 885, if the switch 224 is in the maximum horsepower mode, the controller 301
Makes a check decision to see if the desired gear is between the upshift and downshift speeds as shown in Table 1 above for the current gear. If the determination result is affirmative, the current gear is the optimum gear and it is not possible to shift up.

The current gear is the specific G that the system is in.
If it is not in the optimum gear in S mode, the route 892 leads to block 894. Where current gear and GS
A look-up is performed to determine the upshift speed based on the mode. Next, at block 880, the current desired speed is compared to the upshift speed of the current gear.
If the current vehicle speed is higher than the upshift speed, then block 882 is entered and the required gear is incremented by one. After that, the routine shifts to the second shift control routine 470, and shift to a higher gear is executed.

FIG. 23 shows a mode control routine 616 used when the traveling mode switch 226 is in the ground speed position. The mode control routine 61 of FIG.
6 is executed as the latter half of the 16 millisecond timer routine shown in FIG. The first step in FIG. 23 is to determine whether or not the neutral switch of the direction lever 232 is turned on. If the determination result is affirmative, the process moves to the operation block 906 in which all the solenoids are turned off by the path 904. If the neutral switch is not turned on, the method transitions to decision block 908 where a test decision is made to see if the current configuration of switch states is a valid combination. If the judgment result is negative,
An appropriate error message is displayed on the dashboard 92 and the route 904 transitions to block 906 to put the transmission in neutral.

If the question asked by decision block 908 is answered in the affirmative, then the block 910 is entered which tests to determine if the up switch 244 is on.
If the answer is yes, decision block 912 checks to see if the clutch has been fully released, ie, whether switch 274 of FIG. 2 has been actuated. If the answer is yes, block 914 enters variable ground speed mode. Next, at decision block 916, it is determined whether or not the top of the clutch switch 274 has been released. If the decision result is affirmative, the variable ground speed mode flag is cleared at block 918. At decision block 920,
The forward switch 236 of the directional lever assembly 228
Checked to see if it is included. If the determination result is negative, the determination block 92 is determined by the route 922.
6, check whether the reverse switch 240 of the directional lever assembly 228 is on. If the determination result is negative, the route 928 to the exit 930 is taken.

When the forward switch is turned on in the decision block 920 of FIG. 23, a decision block 934 determines whether the vehicle is stopped, is moving forward, or is moving backward at a low speed. If the result of the judgment is negative, the vehicle is moving backward excessively rapidly, no engagement of the forward gear is recognized, an appropriate error message is displayed, the route 904 is taken to block 906, and the transmission is put in neutral. Be done. Decision block 93
If the response of 4 is affirmative, the demand gear is set equal to the required forward gear. Thereafter, the process proceeds to decision block 926 which asks if the reverse switch is on. If the determination is negative, the routine ends at exit point 930. If the determination is positive, the transmission is
Reverse gears are not allowed, so variable ground speed mode cannot be entered. Next, at decision block 940, it is determined whether the vehicle is stationary, traveling in reverse, or traveling at low speed. If the determination result is negative, it means that the vehicle is moving forward at high speed. In either case, path 904 transitions to block 906, which places transmission 64 in neutral by turning off all solenoids. If the decision result in decision block 940 is affirmative, the requested gear is set equal to the reverse gear requested in block 942 and the exit point 930 is entered to return to FIG.

FIG. 24 is a 66 millisecond timer routine used when the drive mode switch 226 is in the ground speed position, which is used when the switch 226 is in the pulsar position. It replaces 21 dotted line blocks 831. The routine of FIG. 24 begins by checking up switch 244 of shift lever 242 at decision block 952. If not, the down switch 244 of the shift lever 242 is checked at decision block 954. If this is also not the case, block 95 by the negative route.
6, the desired throttle position sensor, ie, the potentiometer 280 shown in FIG. 2, is read by the analog input block 368 shown in FIG. next,
A block 958 displays the acquired value as a percentage value TPS%.
Convert to. Thereafter, a transition is made to decision block 960 and a check is made to see if the system 60 is in the variable ground speed mode entered from block 914 of FIG.
If it is off, exit point 9 of the routine of FIG.
A negative path 962 extending to 64 is taken. If the system is in ground speed mode, the affirmative path is taken from decision block 960 to block 968. At block 968, the controller 302 performs a look-up to determine the throttle setting (ie, engine speed command) required for the desired speed based on the current transmission gear. Note that controller 301 sends the current gear information to controller 302 via the SPI port. The tables used for this operation are shown in FIGS.
It includes data corresponding to the information shown in. 9 and 10
Since the graph in is a straight line, it is not necessary to store every data point. The software is preferably configured to interpolate the percent throttle demand (TPS%). At decision block 969, the controller 302 tests to determine if the result of the look-up at block 968 is less than the throttle setting selected by the vehicle operator. If the determination result is negative, the TPS% value remains unchanged because the maximum engine speed command for which the throttle setting is allowed is being managed. If the decision result in decision block 969 is affirmative, block 970 is entered and the TPS% value is set equal to the result of the look-up in block 968.

At decision block 972, the controller 30
For the period of more than 15 seconds, 2 performs the inspection judgment to confirm whether the actual vehicle speed is less than "desired vehicle speed-1 mph (mile / hour)". If the determination result is negative, the controller 302 determines that the vehicle is operating at a substantially correct speed. If the answer in decision block 972 is affirmative, the control system 90 determines that the loop could not be closed, ie, the actual vehicle speed could not be equal to the desired ground speed. To prevent this from happening, the desired ground speed is set equal to "actual vehicle speed + 1 mile / hour", which
The vehicle is prevented from accelerating excessively when the load on the vehicle is removed.

In FIG. 24, different control sequences are executed depending on whether the up switch 224 or the down switch 250 of the shift lever 242 is operating. If the operator puts the shift lever in the up position, it indicates that the desired speed should be increased. In this case, the determination block 952 is transferred to the block 976 via the positive route, and the desired ground speed value is set to the current desired ground speed value + 0.1 mph. Similarly, when the down switch 250 of the lever 242 is in the ON state, it means that the operator wants to decelerate. Therefore, the flow goes from the decision block 954 of FIG. 24 to the block 978 via the affirmative route, and the internal desired ground speed value is set to the current desired ground speed value-0.1 mph. After that, the process moves from block 976 or 978 to block 956, the desired throttle position sensor is read, and the 66MS timer routine is continuously executed as described above.

Decision block 952 allows the vehicle operator to increase vehicle speed in 0.1 mph increments.
Preferably includes a delay function that operates as follows. When the operator first activates the up switch, block 976 is only executed once in the first 0.75 seconds activated. After that, the up switch is 0.7
If left active for more than 5 seconds, block 976 is executed each time the routine of FIG. 24 is executed. In this way, the operator can increase the desired ground speed more quickly by continuing to hold the shift lever in the up position. Decision block 9
54 preferably includes this type of delay function.

FIGS. 25-27 show the important software changes of the control system 90 required to implement the pseudo gear mode. As described above, this mode is controlled by the control system 90 by the transmission 6
4 is a mode of operation that makes the operator think of it as having more forward gears than are actually present. The apparent number of gears is, if the vehicle is capable of operating at two different speeds or different speed zones, two actual forward gears for each actual forward gear, if desired.
It can be doubled. The higher speed of each gear is preferably 100% or near 100% of the throttle lever setting, while the lower set point is around 80% to 85% of the throttle lever setting. This will be further clarified by the following description.

When the off-road vehicle is set to operate in the pseudo gear mode, the shift-down subroutine and the shift-up subroutine shown in FIGS. 25 and 26 are the shift-down subroutine and the shift-up subroutine shown in FIGS. 18 and 19, respectively. Is a substitute for. The shift-down subroutine of FIG. 25 first determines at decision block 978 whether the requested pseudo gear is higher than first gear. If the determination result is negative, downshifting of the gears of the first speed and lower is impossible, so the route 980 to the subroutine exit point 981 is taken. If the requested pseudo gear is higher than the first speed, the process proceeds to block 982, and the requested pseudo gear value is decreased by 1. Thereafter, decision block 983 determines if the requested pseudo gear value is even. If the determination result is affirmative, the determination block 984 is
It is determined whether the requested pseudo gear is higher than the first speed. If the determination result is positive, the actual requested gear is block 985.
Can be reduced by 1. Decision block 983 or 984
If the response is negative, the subroutine simply exits at point 98.
Return through 1.

The shift-up subroutine of FIG. 26 is similar to the shift-down subroutine described above. at first,
At decision block 988, a test determination is made as to whether the requested pseudo gear is less than 24, and if the determination result is negative, the route 9 is determined.
Go to exit point 991 via 90. The reason is that the prototype transmission has only 12 actual gears, and in this example only 24 pseudo gears. Therefore, the number of pseudo gears does not exceed 24.

If the question is answered in the affirmative at decision block 988, upshifting is possible and block 992.
Move to. The requested pseudo gear value is then reduced by 1. A software decision block 993 then tests to determine if the requested pseudo gear is odd. If the determination result is negative, the subroutine is exited. If the answer is yes, decision block 994 tests to determine if the actual gear requested is less than twelve. If the determination result is affirmative, an actual gear shift is required to perform the upshift, and the block 994 sets the requested gear to 1
Increment only. Then exit the subroutine.

Both the downshift subroutine and the upshift subroutine described above decrement or increment the pseudo gear value and the required gear value. The required gear value is shown in FIG.
Used as described above with reference to FIG. The pseudo gear value is transferred to the controller 302 via the SPI communication path described in FIG. 4 by the controller 301 in which the software codes of the shift down subroutine and the shift up subroutine are stored in the pseudo gear mode. An example of the requested pseudo gear value thus transferred will be described with reference to FIG. 27 below.

FIG. 27 shows the 66 millisecond timer routine required to operate an off-road vehicle in pseudo gear mode. As shown, this is the dotted block 831 of FIG.
Used in place of the 66 millisecond timer routine specified in. In the routine of FIG. 27, the desired throttle position sensor is read in block 1002, which is shown in FIG.
Of the same operations performed by block 832 of FIG. Next, decision block 1004 determines if the requested pseudo gear is even or odd. If odd, the affirmative path to block 1006 is taken. If it is even,
The negative route to block 1008 is taken. Block 1
In 006, the current throttle percentage value is 0.81 of the current value read from the throttle lever pot 280.
Set to, which is the lower engine speed. At block 1008, the throttle position percentage value is set to 100% of the current value read from the throttle lever pot 280, resulting in the higher engine speed for the current actual gear. Therefore, one skilled in the art should understand that even if within the same actual gear range, selecting an odd pseudo gear will result in a slightly lower engine speed than an even pseudo gear. Is. Therefore, the engine of the vehicle operates for each actual gear at one of the two speeds, i.e. at the set point resulting in two different ground speeds. In this way, a prototype vehicle with 12 actual gears feels to the operator as having 24 gears. Note that the throttle position is adjustable by the operator, which allows the operator to increase or decrease the maximum engine speed. Since the current throttle command is set as a predetermined part of the throttle speed pot setting, the operator can simultaneously change the ground speeds of the respective pseudo gears in proportion to each other by the engine speed throttle lever. In addition, this feature allows the transmission 64 to operate the transmission 64 at almost any ground speed desired by the operator by adjusting the maximum allowable engine speed using the transmission control system 90. Therefore, the name can be referred to as an "engine variable" transmission control system.

Those skilled in the art will understand that the method described with reference to FIGS. 25 to 27 can be applied to the case where the actual gear has three set points instead of two set points. You can understand. For example, the 12-gear transmission of the prototype system of the present invention provides three set points for each actual gear,
It is possible as if it were a 36-gear transmission. In such a system, the maximum set point is preferably set to 100% of the throttle pot setting, the intermediate set point is set to 87.5% of the throttle pot setting, and the third minimum set point is 75% of the throttle pot setting. Set to%. Those of ordinary skill in the art will appreciate that these percentages may be adjusted to the throttle pot setting of 10
It will be appreciated that it can be adjusted to 0%, 90% and 80%, or other percentage values. Control system 90
Is set to operate in pseudo gear mode, the software that accesses the subroutine of FIG. 25 or 26 instead of FIG. 18 or 19 by calling the upshift or downshift subroutine in FIGS. 15, 16 and 17. Movement of shift lever 242 causes the pseudo gear value to be increased or decreased to produce a wear code. Except for those calls to various up-shift and down-shift subroutines, the mode control and sequential shifting software of FIGS. 15, 16 and 17 remain unchanged.

The communication routines used to transfer messages between frames 1 and 2, ie, controller 301 and controller 302, are described below. As mentioned above, the controller 301 preferably has its own software code configured to operate as a master controller. The SPI transfer message routine is a 16MS timer routine, shown as block 626 at the bottom of FIG. Therefore, those messages are transferred by the master controller 301 approximately every 16 milliseconds. The routine at block 626 executes as follows. First, information about the current engine speed, the current vehicle speed, and the current gear and switch status is stored in the buffer register of the RAM. Next, the synchronous peripheral interface (SPI)
Are instructed to send those four values to the controller 302, one byte at a time. Since this SPI is an interrupt driven type, one byte is transferred, and a transfer interrupt is generated every time the transfer buffer becomes empty. This interrupt code loads the next byte from the buffer and starts the transfer. This process is repeated until the entire message has been transferred. As each transfer byte is received, it causes an interrupt by the receiving SPI to be processed by the controller 302. This interrupt code in controller 302 simply loads these bytes into a designated memory location in RAM. Then, as indicated by block 806 in FIG. 20, these SPI messages are accessed from their storage locations, subject to error checking, and controller 3 that needs to access those parameters.
02 is ready for use by other parts of the software code.

Within a few microseconds after receiving the completion message from the controller 301, the controller 302
Block 806 of the main loop (FIG. 20) processes the received message and sends a response to the received information.

In this routine, the potentiometer 28
The current throttle position measured by 0 and the desired ground speed are loaded into a buffer register for transfer to the controller 301 through the SPI port. Also, if desired, functionality checks, error codes or some other information can be passed as part of the transfer in either direction, simply by adding such a code to the transferred message. This can be done by simply increasing the number of bytes transferred.

For example, information about the mode that the control system 60 is currently in can be transferred by the controller 301 to the controller 302. Bits or flags that indicate whether or not you are in variable ground speed mode (which mode, if any), whether or not the up or down switch is activated, and whether you are in the desired gear Can be sent. Similarly, a command state such as a variable ground speed control cancellation request can be transferred between controllers. Such a request may also be issued by the controller 302 if the software is programmed to protect against undesirable engine conditions such as hunting. The undesired engine condition is a condition that may cause the controller 301 to exit the variable ground speed mode and display an appropriate error code message.

Those skilled in the art will appreciate that these electronic controllers used to control the power shift transmission or the engine or both operate in real time. Therefore, in designing software such as the various timing control loops described above, it is guaranteed that all the important parts of the software code related to vehicle operation are executed at regular intervals corresponding to an extremely short time of 1 second or less. It is desirable to take measures to This ensures an agile response to any changes in internal or external conditions.

Those of ordinary skill in the art of designing hardware and software for electronic control systems used in heavy duty off-road vehicles should understand the above detailed description and the hardware block diagrams and software flow diagrams. In order to utilize the electronic control system and method described above, it will be possible to easily design an appropriate hardware circuit using a microprocessor and create an appropriate program. Such programs can be written in multiple assembly languages or high level languages such as C. The programs are preferably written in a computer programming language specifically designed for the microprocessor at the heart of the electronic controller used in the control system. For example, Motorola H
The prototype system of the present invention using two C6811 microprocessors uses Motorola's assembly language for these processors. The reason is that this language is fast, compact and highly efficient. To be extremely compact, the code is written by a number of separate routines, as described above, thus eliminating the need to store the same code.

Although the above detailed description has been directed to a power shift transmission having twelve forward gears and two reverse gears, those skilled in the art will appreciate that the idea of the present invention is, for example, eight forward gears. It should be understood that it is equally applicable to other power shift transmissions such as having a gear and two reverse gears.

The control system and control method of the present invention are
It is preferably used for agricultural vehicles such as tractors and combine harvesters, but can also be applied to various other types of heavy-duty off-road vehicles such as large dump trucks, road graders, and shovel loaders. It is important to use an engine with a relatively broad torque-engine speed curve to maximize the benefits gained by implementing the system and method of the present invention. When using such an engine, the concept of pseudo gear becomes practical because the engine can operate at two or more different speeds for each transmission gear, and also in comfort mode, fuel saving mode and maximum horsepower mode. It will be extremely practical.

The term "off-road vehicle" as used herein is intended to include motor vehicles primarily used in agriculture, construction or mining. Such off-road vehicles are not limited to the above examples, but include tractors, combiners, dump trucks, shovel loaders, bulldozers, and road graders. The term "power shift transmission" may be coupled together in a power transmission relationship by the selective engagement of gears operated by two or more hydraulically actuated clutches and their associated electrically actuated hydraulic valves 1.
Includes a relatively heavy duty power transmission device having one or more rotary power input shafts and one rotary power output shaft.

As used herein, the term "electrically actuated hydraulic valve" includes solenoid valves, coils, electric windings, and any other type of hydraulic valve having an electrical operator.

As used herein, the term “electrical signal”
Includes DC signals and pulsating signals, which may (but need not) have periodic or repetitive waveforms such as square waves, triangle waves or sine waves. It also includes signals having a net DC component, such as the PWM signals described herein.

As used herein, the term "controller means" or "controller" refers to one or more MSI, L operable by firmware or software.
It includes a microprocessor, microcomputer or digital electronic system using SI or VLSI integrated circuits. Both firmware and software are considered to take the form of stored program control.

[Brief description of drawings]

FIG. 1 is a graph showing two curves of torque-engine speed (RPM), illustrating the difference between an old engine and a new engine of an off-road vehicle.

FIG. 2 is a block diagram showing an example of the overall configuration of an electronic control system of the present invention, showing an electronic control system having various operator interface devices and a vehicle sensor coupled to an electronic engine controller of a transmission and an engine. ing.

FIG. 3 shows a solenoid excitation pattern with each gear of a transmission having 12 forward gears and 2 reverse gears.

4 is a detailed block diagram of first and second electronic controllers used in the control system of FIG. 2 and electrical connections to and between the controllers.

FIG. 5 is an input voltage-engine speed diagram for a particular engine controller.

FIG. 6 relates to a specific gear of the transmission of FIG.
It is the figure which drew when using the ground speed of 1000RPM, 2000RPM, and 300RPM for ground speed matching purposes.

7 is a desired ground speed in maximum horsepower mode and fuel saving mode when the transmission of FIG. 2 is used.
It is a figure which shows the relationship of a desired forward gear.

FIG. 8 shows a shift map of the transmission of FIG. 2, where automatic shift-up points for each forward gear,
The shift down point is shown with respect to the vehicle speed.

9 shows a throttle map for the forward gears 1-6 of the transmission of FIG.

FIG. 10: Forward gears 7-1 of the transmission of FIG.
2 is a throttle map for 2.

11 is a flow diagram illustrating software used to operate the first or transmission controller of the control system of FIG. 2 of the present invention in its pulsar transmission mode, illustrating each function of the main software loop.

12 is a flow diagram illustrating software used to operate the first or transmission controller of the control system of FIG. 2 of the present invention in its pulsar transmission mode for controlling shifts between gears of the transmission. The 4 millisecond shift control software loop used will be described.

13 is a flow diagram illustrating software used to operate the first or transmission controller of the control system of FIG. 2 of the present invention in its pulsar transmission mode for controlling shifts between gears of the transmission. The 4 millisecond shift control software loop used will be described.

FIG. 14 is a flow diagram illustrating software used to operate the first or transmission controller of the control system of FIG. 2 of the present invention in its pulsar transmission mode, for updating and controlling each part of the first transmission. The 16 millisecond timer software routine used will be described.

FIG. 15 is a flow diagram illustrating software used to operate the first or transmission controller of the control system of FIG. 2 of the present invention in its pulser transmission mode, illustrating a mode control software routine.

16 is a flow diagram illustrating software used to operate the first or transmission controller of the control system of FIG. 2 of the present invention in its pulsar transmission mode, illustrating a mode control software routine.

FIG. 17 is a flow diagram illustrating software used to operate the first or transmission controller of the control system of FIG. 2 of the present invention in its pulser transmission mode, illustrating a sequential shifting routine.

FIG. 18 is a flow diagram illustrating software used to operate the first or transmission controller of the control system of FIG. 2 of the present invention in its pulsar transmission mode, describing the downshift and upshift routines, respectively. To do.

FIG. 19 is a flow diagram illustrating software used to operate the first or transmission controller of the control system of FIG. 2 of the present invention in its pulser transmission mode, describing the downshift and upshift routines, respectively. To do.

FIG. 20 is a flow diagram illustrating software used to operate the second or engine controller of the control system of FIG. 2 of the present invention in its normal transmission mode, illustrating the function of the main software loop.

FIG. 21 is a flow chart illustrating software used to operate the second or engine controller of the control system of FIG. 2 of the present invention in its normal transmission mode, illustrating a 16 second millitimer routine.

22 is a flow chart illustrating a modification of the software used to operate the transmission controller of the control system of FIG. 2 of the present invention in its variable ground speed control mode for controlling gear shifts of a transmission. The 4 millisecond shift control software loop used in the above will be described.

23 is a flow chart illustrating a modification of software used to operate the transmission controller of the control system of FIG. 2 of the present invention in its variable ground speed control mode, illustrating a mode control routine.

24 shows the engine controller of the control system of FIG. 2 of the present invention in its variable ground speed control mode, modification 6;
6 is a flow diagram illustrating modification of software used to run a 6 millisecond timer routine.

25 is a flow chart illustrating a modification of software used to operate the transmission controller of the control system of FIG. 2 of the present invention in its pseudo gear control mode, illustrating upshift and downshift routines, respectively. To do.

FIG. 26 is a flow chart illustrating a modification of software used to operate the transmission controller of the control system of FIG. 2 of the present invention in its pseudo gear control mode, illustrating upshift and downshift routines, respectively. To do.

27 is a flow chart illustrating a modification of the software used to operate the engine controller of the FIG. 2 control system of the present invention in its pseudo gear mode.

[Explanation of symbols]

36,44 Torque curve 38,46 Horsepower curve 40 Power band 42 Horizontal line 48 Torque portion 50 Drive system 52 Engine 54 Engine controller 56 Engine output drive shaft 58 Joint means 60 Transmission control system 62 Input drive shaft 64 Transmission 66 Hydraulic valve 68 Output drive Axis 70 Output branch (PTO) Axis 72, 74, 76 Clutch device 90 Electric control system 92 Dashboard 94 Transmission control switch / lever set 96 Engine function / accessory control switch set 98 Vehicle ignition switch 100 Throttle lever 102 Controlled electric output unit 104 Reprogramming (PR) Panel 110 Clutch Pedal Assembly 112 Pedal 114 Pivot Lever with Spring 11 Dotted line 118, 142 Variable reluctance sensor 120 Flywheel gear 122 Variable magnetic reluctance sensor 124 Rotating gear 128 Driven wheel 132 Radar horn unit 136 Ground surface 138 Tire 144 Gear 146 Axle 150 to 158 port 160 to 180 Electric line (line) 182 Power supply 184 Power supply switching relay section 186 Monitoring timer circuit 190 Microprocessor 192 Serial port interface 194 Buffer / driver / latch (BDL) section 196-208 Display section 210, 260, 262, 320 Line 212, 214, 216 Segment 224, 226, 256 , 258 Changeover switch 228, 230 Pivot lever assembly 232 Pivot hand lever (direction lever) 234, 244, 278 Base 236, 238, 240 Switch 242 Pivot hand lever (shift lever) 246, 250 Limit switch 272, 274 Switch 280 Position indicating device (throttle pot) 284 Release button 290 Table 301, 302, 351 Controller 303, 304 Microprocessor 306 Read Dedicated memory (ROM) 308 Bus driver (chip selection (BD / CS) circuit) 312 Erasable programmable read only memory (EEPROM) 316 Digital input circuit 318 Analog-digital input circuit 324 Frequency input circuit 326, 328 Pulse waveform signal 332-340,358 Port 342 Solenoid 344-346,394 Electric Circuit 348,349 Terminal 360-390 Analog Output (I / O) circuit or port 392 block 396 the contactor 398 signal path 400 D / A converter 402 conductor line command signal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kevin El Breckestran United States 58103 North Dakota Fargo Twenty Third Avenue Avenue South 2922 (72) Inventor Barry Dee Bachelor United States 58078・ North Dakota ・ West Fargo Eights Avenue New East ・ 619

Claims (34)

[Claims] 1. An electronic control system for a self-propelled off-road vehicle having an engine and a power shift transmission having a plurality of gears, the rotational speed at which the engine is operated while controlling the power shift transmission. An electronic control system for providing one or more control signals to the engine to specify a particular one of the forward gears in which the power shift transmission is to operate. First electronic controller means operable under stored program control for providing a transmission control signal and one of a number of different engine speeds within a predetermined range
Second electronic controller means operable under stored program control to provide one or more engine control signals necessary to instruct the engine to operate in one A first electrical output means for instructing the transmission to operate in a particular gear specified by a current transmission control signal; and a second electronic controller means. Communication means for transmitting and receiving digital signals between the second controller means and the second controller means for instructing the engine to operate at a specific engine speed indicated by the engine control signal. A communication means for transmitting and receiving digital signals between the second electric output means and the first electronic controller means. Electronic control system characterized by having and. 2. A display means responsive to at least one of said controller means for indicating to an operator the gear at which said transmission is currently operating and the rotational speed at which said engine is operating. The electronic control system according to claim 1. 3. The display means is operated by a selected one of the first and second controller means, and the selected one of the first and second controller means is displayed by the display means. 3. The electronic control system according to claim 2, further comprising receiving information from the other controller means. 4. Interface means for allowing an operator to select which gear the transmission should operate in, and operator any engine speed within a predetermined range of allowable speed at which the transmission operates. 2. An electronic control system according to claim 1, further comprising operator interface means for enabling selection by the operator. 5. The first controller means further includes automatic means for controlling the shift of the transmission from the current gear to the high speed gear upon receipt of a shift up command, and a current means upon receipt of a shift down command. Automatic means for controlling the shift of the transmission from gears to low speed gears and, if preceded by a shift-up command, at predetermined time intervals after completion of a shift by the transmission in response to the previous shift-up command. An automatic means for generating a series of consecutive shift-up commands consisting of the generated commands, and, if there is a previous shift-down command, after completion of a shift by the transmission in response to the previous shift-down command. A series of consecutive commands that are generated at given time intervals Electronic control system according to claim 1, characterized in that it comprises an automatic means for generating a downshift command. 6. The first controller means further comprises automatic determination means for determining which gear to shift next based at least in part on vehicle ground speed. Item 2. The electronic control system according to item 1. 7. The electronic control system according to claim 6, wherein said automatic determination means has means for checking whether or not ground speed matching should be used for performing the next shift. 8. The power shift transmission includes a series of hydraulic clutch devices and associated solenoid actuation control valves for filling the pack when the solenoids of the associated valves are energized, A first controller means further means for storing specific information for determining a time delay used in shifting the power shift transmission from a gear that the transmission is currently in to another desired gear. The electronic control system according to claim 1, further comprising: an automatic execution unit for executing a shift of the power shift transmission according to a timing delay determined also based on the stored information. 9. The first controller means further includes means for receiving a signal having a period inversely proportional to the ground speed of the vehicle, means for determining the ground speed of the vehicle from the received signal, and Means for storing the ground speed as a digital value for use by the automatic determination means. 10. The received signal, the period of which is inversely proportional to ground speed, is obtained from a rotating component directly connected to the output power shaft of the vehicle, thereby displaying an apparent ground speed. The electronic control system according to claim 9, wherein: 11. The electronic control system according to claim 9, wherein the received signal whose cycle is inversely proportional to the ground speed is obtained from a mechanism for displaying the true vehicle ground speed. 12. The electronic control system of claim 1, further comprising means for generating a control signal indicating a value corresponding to a current throttle position selected by a vehicle operator. Automatic means for facilitating a change in the value of the engine control signal in response to a change in the throttle position selected by the operator, the controller means further responsive to a change in the value of the control signal indicating the current throttle position. The electronic control system according to claim 1, further comprising: a conversion unit. 13. An electronic control system for a self-propelled off-road vehicle having an engine and a multi-gear power shift transmission, the control system controlling the power shift transmission and specifying a rotational speed at which the engine operates. An electronic control system for supplying the engine with one or more control signals for controlling the engine, the electronic control system including means for receiving an operator selection of a desired vehicle speed; And providing the transmission control signal required to command operation at any one of the predetermined engine speeds to the engine to operate at any predetermined speed within the range of possible engine speeds. An electronic co-processor to provide one or more engine control signals needed to command A controller means for operating the transmission in a predetermined transmission gear dictated by a transmission control signal, the controller means having a predetermined electrical output means for operating the transmission. Second for operating the engine at engine speed
And an electric control means for responding to the receiving means for selecting a transmission gear required to obtain a desired vehicle speed and a desired engine speed. .. 14. The electronic control system according to claim 13, wherein the controller means operates under stored program control. 15. The electronic controller means includes first and second electronic controllers, each controller having communication means for exchanging information with the other controller means, and 15. The electronic control system of claim 14, wherein each controller is operable under the control of a different stored program. 16. A display means connected to the controller means for receiving a display signal from the controller means, the vehicle speed being present, a current gear in which the transmission is operating, and a current engine speed at which the engine is operating. 15. The electronic control system according to claim 14, further comprising display means for instructing an operator. 17. The electronic controller further comprises: a first gear for responsive to the selected transmission gear and desired engine speed for shifting the transmission by those gears necessary to force the transmission into the selected transmission gear. 15. An electronic control system as claimed in claim 14, characterized in that it comprises two automatic means and a third automatic means responsive to the selected engine speed for rotating the engine at a desired engine speed. 18. The second automatic means completes the previous shift command, if any, in order to eliminate a significant difference between the actual engine speed and the desired engine speed. 18. An electronic control system according to claim 17, characterized in that it comprises means for generating a series of gearshift commands, which will later consist of commands generated at predefined time intervals. 19. The electronic means further comprises means for adjusting a predetermined time interval after completion of a previous shift command depending on the degree to which the desired ground speed approximates the current ground speed. Claim 1 characterized by
8. Electronic control system according to item 8. 20. The controller means further comprises automatic determination means for determining, based at least in part on vehicle ground speed, which gear should shift to the next gear. 13. The electronic control system according to 13. 21. The automatic determination means of claim 20, further comprising means for checking whether ground speed matching should be used to assist in assigning the next gear to shift. Electronic control system. 22. An operator input means having a fuel economy mode and a maximum power mode as selectable modes, the engine input means being one of a plurality of modes in which the engine can operate.
14. The electronic control system of claim 13, further comprising operator input means connected to the controller means to receive operator selection of one of the modes. 23. When the maximum power mode is selected, the electronic controller means selects the transmission gear and engine speed such that the engine / transmission combination effectively produces maximum output horsepower in response to the desired vehicle speed. 23. The electronic control system according to claim 22, wherein: 24. When a fuel saving mode is selected, the electronic controller means is responsive to the desired vehicle speed and a transmission gear and engine / transmission combination which at the selected ground speed provides a virtually optimal fuel saving. 23. The electronic control system according to claim 22, wherein the engine speed is selected. 25. An electronic control system for a self-propelled off-road vehicle having an engine and a multi-gear power shift transmission, the control system controlling the power shift transmission and specifying a rotational speed at which the engine operates. An electronic control system for supplying one or more control signals to the engine for receiving the desired vehicle speed selected by an operator; and the engine being operable, at least Means for receiving an operator selected one of a number of modes including a fuel saving mode and a maximum power mode, and for commanding the power shift transmission in any one of its forward gears Provides and can provide the required transmission control signals An electronic controller means for providing one or more engine control signals necessary to command the engine to operate at any engine speed within the range of various engine speeds. When a mode is selected, the controller means, depending on the desired vehicle speed, selects a transmission gear and engine speed such that the engine / transmission combination produces substantially maximum output horsepower, and
When the fuel saving mode is selected, the transmission gear and engine speed are selected so that the engine / transmission combination of the selected ground speed provides a virtually optimal fuel saving, depending on the desired vehicle speed. The electronic control system as described above. 26. The electronic controller means is instructed by an engine control signal, and first electrical output means for instructing the transmission to operate in a particular transmission gear indicated by the transmission control signal. Second electrical output means for instructing the engine to operate at a specific engine speed, the transmission gear required to shift to the desired transmission gear, and the desired desire to reach the desired vehicle speed. 26. An electronic control system according to claim 25, comprising first automatic means responsive to said receiving means for selecting engine speed. 27. A method of providing an operator interface for a self-propelled off-road vehicle having an engine and a multi-gear power shift transmission controlled by an electronic control system, the method comprising more forward gears than are actually present. And (b) instructing the transmission to operate in a particular actual transmission gear by the electronic control system, and (b) the electronic control system. Commanding the engine to operate at a particular desired engine speed according to: (c) the operator that the transmission is operating in a transmission gear other than the actual transmission gear in which it is actually operating. Knowledge And a step of causing the operator interface to be provided. 28. The transmission has X (where X is an integer having a value greater than or equal to 4) forward gears, the method further comprising operator display information from the electronic controller 28. The method of claim 27, comprising the step of simulating having 2X forward gears. 29. (a) Communicating an operator-selected desired vehicle speed to the electronic control system; and (b) a particular actual transmission gear and actual engine on which the transmission should operate to reach the desired vehicle speed. 29. The method of claim 28, further comprising the step of determining a rotational speed. 30. (d) For each actual transmission gear, the method further comprises the step of providing two pseudo transmission gears, a low speed pseudo gear and a high speed pseudo gear, according to information programmed in said electronic controller. 27. The method according to claim 27, wherein
The method described. 31. The method of claim 30, further comprising the step of assigning to each low speed pseudo gear and each high speed pseudo gear of each actual gear a range of engine speeds associated with each pseudo gear. And for each actual gear, the range of engine speeds assigned to the relevant low speed simulated gears is generally less than the range of engine speeds assigned to the high speed simulated gears. 30. The method described in 30. 32. Electronic control with operator interface for instructing an operator that the transmission has more forward transmission gears than actually exist for an off-road vehicle having an engine and a multi-gear power shift transmission. A system comprising a transmission control signal required to instruct the power shift transmission to operate in any one of its forward gears, and a number of different desired engine speeds for the engine. Electronic controller means for operating in accordance with one or more stored programs to provide engine control signals required to command one of the transmission control signals from the electronic controller means A first electrical output means for instructing the transmission to operate at a particular actual transmission gear indicated, and a particular engine indicated by one or more engine control signals from the electronic controller means. Second electrical output means for instructing the engine to operate at rpm, and in response to the controller means, operating in a transmission gear other than the actual transmission gear in which the transmission is currently operating. An electronic control system comprising: a display unit for notifying an operator that the operation is being performed. 33. The controller means comprises first electronic controller means for generating the transmission control signal, and second electronic controller means for generating the one or more engine control signals. The first and second electronic controller means each have a communication means for exchanging information with each other, and each of them can operate under the control of different stored programs. 33. The electronic control system according to claim 32, wherein: 34. The display means is operated by a selected one of the first and second electronic controller means, and the selected one of the first and second electronic controller means is 34. The electronic control system according to claim 33, wherein information displayed to the operator by the display means is received from the other of the electronic controller means.