NL192799C - Electronic steering system for an automatic transmission mechanism of a vehicle. - Google Patents

Description

1 192799

Electronic steering system for an automatic transmission mechanism of a vehicle

The invention relates to an electronic control device for an automatic transmission mechanism of a vehicle, to which the operating parameters are entered by various sensors as input signals: the gear to which has just been switched; the throttle angle set via the accelerator pedal; the engine speed; and the vehicle speed, the electronic steering device being provided with a memory device and logically processing these input signals and generating output signals for driving a transmission mechanism actuator by means of stored characteristic shift lines, with change means provided for the stored characteristic shift lines by modifying at least one of the operating parameters.

Such a device is known from United States Patent Specification 4,044,634.

The object of the invention is to improve the known device in such a way that the switching point of the transmission mechanism is controlled without control fluctuations.

According to the invention, this improvement is achieved in that the modifying means is adapted to change the engine speed ordering upshifts and downshifts in response to the input signal representative of the engine speed by modifying the stored characteristic shift lines during a predetermined time interval following the choice of a new gear ratio.

Further objects and possibilities for practicing the invention will become apparent from the following description in connection with the drawing, in which: figure 1 schematically indicates the components and interconnections of a mechanical automatic transmission in accordance with the invention; Figure 2 schematically shows the components of the mechanical automatic transmission which interact with the motor; Figure 3 is a full cross-sectional view of a transmission synchronizer and clutch device according to the invention; Figures 4 and 4a are a table of the signal identity, generation point and processing in the central processing unit; Figure 5 is a schematic of the speed and synchronization circuit; Figure 6 is a schematic of the accelerator circuit; Figure 7 is a schematic of the instruction logic circuit; Figure 8 is a schematic of switching initiation circuit; Figure 9 is a schematic of the clutch control circuitry; and FIG. 10 is a graph of the engine speed against the accelerator pedal position showing the shift points of the mechanical automatic transmission.

Figure 1 schematically shows the components of the mechanical automatic transmission which is generally indicated by reference numeral 10. The automatic transmission 10 comprises a 40 conventional multi-speed gear transmission 11 operatively connected to a conventional friction plate type clutch 12 which in turn is connected to a motor 13. The output of the automatic transmission 10 is provided by an output shaft 14 to a suitable vehicle component such as a differential, which is not part of the invention.

The base power train components 12-14, which have just been discussed, affect and are monitored 45 by various devices which will be discussed in more detail below. These include a fuel shutoff valve 15 which blocks fuel flow to the engine, a throttle position monitor 16 that senses the position of the throttle or accelerator pedal of the vehicle, an engine speed sensor 17 that senses the speed of the engine 13, a clutch operator 18 that clutch 12 couples and disengages, a counter shaft speed sensor 19 and an output shaft speed sensor 50 which senses the speed of the counter or input shaft of the transmission 11 and the output shaft 14 of the transmission 11, a transmission shift operating device 21 which couples and disengages a selected gear the transmission 11, and a counter-axle brake device 22 and a counter-axle synchronizer gear 23, which cooperatively synchronize the elements of the transmission 11 to be coupled.

These devices provide information and accept instructions from a central processing unit 24. The processing unit 24 includes analog and digital electronic calculation and logic circuits shown in Figures 5 to 9, which will be described in more detail below. The 192799 2 central processing unit 24 also accepts an information signal (IGN) from an ignition switch 25 which powers the entire mechanical automatic transmission 10 and comes from a shift control device 26, which in turn accepts driving instructions as to the operating mode of the transmission 10. The central processing unit 24 provides a signal (ALARM) to an audible alarm 27, indicating incorrect or unsafe working conditions. An electrical power source 28 and a pressurized air source 29 provide proper electrical power and pressurized air to the various components of the mechanical automatic transmission 10 shown in Figure 1.

Figure 2 shows the components of the mechanical automatic transmission 10 which are associated with the engine 13. The fuel shut-off valve 15 is arranged in a fuel line 30, which supplies fuel to the engine 13. The shut-off valve 15 is controlled by a central processing unit 24. The valve 15 is of the normally closed type, but is open in normal operation due to the presence of an excitation signal (FV) from the central processing unit 24. When it is necessary to decrease the speed of the engine during the gear shifting interval when the coupling 12 15 is disengaged, valve 15 is turned off and fuel supply to engine 13 is stopped.

Also associated with the engine 13 is the throttle position monitor 16. A throttle 31 mechanically controls a fuel gauge 32 such as a carburettor or diesel injector by means of a joint 33. The fuel gauge 32 controls the speed of the engine 13 by adjusting the fuel flow rate thereto. response to the position of the accelerator pedal 31 in a conventional manner. Link 33 also operates two switches 34 and 35 and a transducer 36. The first switch, an accelerator switch 34, senses the initial movement of the accelerator 31 and closes to indicate that the driver's foot is present on the accelerator 31 which provides the accelerator pedal logic signal (TS). The second switch, the throttle on the plank switch 35, closes to indicate that the accelerator pedal 31 is fully depressed down to the plank and provides the fully depressed throttle pedal signal (RTD). The transducer 36, which is in the form of a potentiometer, provides a resistance signal (TP) which varies directly proportional to the position of the accelerator pedal 31 from a free step when the first switch 34 is open to a fully depressed accelerator pedal position when the second switch 35 is closed. The on-off signals from the switches 34 and 35, namely TS and RTD and the proportional resistance signal from the converter 36, namely TP, are all supplied to the central processing unit 24 and are used by the logic and control circuits therein to control the automatic transmission 10.

Adjacent to the accelerator pedal 31, a brake pedal 37 is mounted and activates the vehicle brake system (not shown) in a conventional manner. A brake switch 38 which closes when the brake pedal 37 is pressed and the vehicle braking system is energized provides a logic signal (BS) 35 indicating this condition for use by the central processing unit 24.

Also associated with the motor 13 is a motor speed sensor 17, such as a magnetic sensor arranged in radial line with a gear such as a motor flywheel 39. The teeth on the wheel 39 induce fluctuations in the magnetic circuit of the sensor, which induces voltage fluctuations in a coil, from which the output signal is supplied to the central processing unit 24.

40 In Fig. 3, the clutch 12, the clutch operator 18, the transmission 11, the transmission speed sensor 19 and 20, the transmission operator 21, the synchronizer braking device 22 and the synchronizer gear device 23 are shown.

The clutch is a conventional friction plate clutch with a spring-biased, circular, axially translatable clutch plate 40 which is brought into contact with a corresponding 45 plate attached to the engine output shaft (not shown) and is retracted by the action of the several springs 41. The clutch plate 40 moves in response to movement of a number of second-class levers 42 which transmit the movement of an actuator 43 to the clutch plate 40. The actuator is in turn affected by an expandable annular diaphragm 44 comprising one annular wall chamber 45 into which pressurized air 50 is introduced. The air is introduced into the chamber 45 through a passage 46. A number of conventional electrically operated two-position solenoid valves control the air flow and thus the air pressure in the passage 46 and the chambers 45 from 0 p.s.i. to maximum air pressure.

A fine fill valve 47 has an opening of about 0.020 x 2.54 cm when energized by the fine fill signal (FF) from the central processing unit 24, pressurized air 55 is introduced into the passage 46 at a relatively low speed. The coarse fill valve 48 has an opening diameter of about 0.045 x 2.54 cm and when energized by the coarse fill signal (CF) from the decentral processing unit 24, pressurized air is introduced into the passage 46 at a relatively high speed. . In normal operation, the valves 47 and 48 are actuated in subsequent order, i.e., first the fine fill valve 47 is energized to slowly fill the chamber 45 or gradually increase the pressure therein, then the coarse fill valve 48 is energized while the fine fill valve 47 is energized remains to quickly fill chamber 45.

Corresponding devices and operating sequences control the pressurized air outlet from the coupling chamber 45. A fine exhaust valve 50 has an opening diameter of about 0.033 x 2.54 cm and when energized by the fine exhaust signal (FE) from central processing unit 24 is pressurized introduced air into chamber 45 and passage 46 vented to the atmosphere at a relatively small speed. A coarse outlet valve 51 has an opening diameter of about 0.060 x 2.54 cm and when energized by the coarse outlet signal (CE) from the central processing unit 24, pressurized air exits into chamber 45 and passage 46 at a relatively high speed. A rapid dump valve 52 has an opening diameter of about 0.400 x 2.54 cm and when energized, pressurized air is introduced into chamber 45 and passage 46 instantaneously into the atmosphere. The three exhaust valves 50, 51 and 52 are subsequently additionally actuated, that is, first the fine exhaust valve 50 is actuated by the FE signal to slowly empty the coupling chamber 45 or gradually decrease the pressure therein, then the coarse exhaust valve 51 is actuated by the CE signal, while the fine outlet valve 50 remains energized and a faster emptying of the chamber 45 is achieved. If necessary, all three valves 50, 51 and 52 are energized and the air pressure in chamber 45 will drop almost instantaneously to zero.

Two pressure switches 53 and 54 test the air pressure in the passage 46 and provide signals to the central processing unit 24. The low pressure switch 53 is normally closed and opens when the pressure in the passage 46 is around 16 p.s.i. for supplying a low pressure signal (LP) to the central processing unit 24. This pressure represents the point at which the force is supplied by the pressurized air in the chamber 45 and after supply to the clutch plate 40 is equal to the pre-load. in the return spring 41. Therefore, the opening and closing of the pressure switch 53 signals to the central processing unit 24 that either the clutch movement is outstanding or that it has just ceased.

The high pressure switch 54 closes when the air pressure in the passage 46 is approximately 45 p.s.i. and supplies a high pressure signal (HP) to the central processing unit 24. This pressure represents the point at which the force provided by the pressurized air in the chamber 45 is sufficient to rest positively in the clutch plate 40 on the complementary clutch plate mounted on the output ac / an motor 13. At 55 psi the torque of the clutch is equal to the maximum engine torque. Limiting the clutch pressure at this level causes the clutch to slip when transitional control line moments are to be developed in addition to the motor torque. This can prevent control line damage.

Figure 3 also shows the transmission 11 which is of the conventional twin-counter-shaft type with an input shaft 55, a number of constantly interlocking drive gears 56 and driven gears 58, which transmit power with fixed, selectable reduction ratios, and two counter-shafts 57 and 57A (not shown). The coupling of a selected gear of the plurality of driven gears 58 is accomplished by a number of axially translatable slotted jaw clutches 59 mounted coaxially on the output shaft 14 and central pairs of the driven gears 58. Insofar as the transmission gear and shift mechanism are conventional and are believed to be readily understood by those skilled in the art, these will not be further described.

The claw clutches 59 are advanced or retracted to establish a clutch with the gear shift operator 21. The gear shift operator 21 45 includes a plurality of three position pneumatic cylinders 60, each of the cylinders 60 driving one of the claw clutches 59 to a forward or reverse clutch. position and a central neutral position by means of a fork device 62. Figure 3 shows only two pneumatic cylinders 60 and the associated valves in cross section for clarity. It is to be understood that the number of cylinders 60 should be equal to the number of claw clutches 59 and usually 50 the number of claw clutches 59 will be half of the total number of forward and reverse gear ratios to be selected in the transmission since each claw clutch 59 will be the clutch of two gear ratios.

The cylinders 60 each include a self-centering piston 61 which is attached to a corresponding claw coupling 59 by a fork device 69. The pistons 61 each include two end 55 collars 63 and 64 which can slide into the chambers 65 and 66 between the adjacent end of the cylinder 60 and a fixed stop 67 in the wall of the cylinder 60 or a circumferential rib 68 on the exterior surface of the piston 61 which is first brought into contact. This basically creates a 192799 4 piston with main differential surfaces that equalize when the piston is centered. In operation with equal air pressure on both sides of the piston 61, the force imposed in a given direction depends on whether the collars 63 and 64 are in contact with either the fixed stop member 67 or the circumferential cylinder rib 68. When the collar 63 is in contact with the stopper 67, the force generated by the pressurized air against the collar 63 will be grounded against the stopper 67 and only the force generated by the pressurized air against the piston 61 will be available to reposition it. When the collar 64 is adjacent to rib 68 on the cylinder 61, the force generated by the pressurized air against the collar 64 will be added to that generated by the air pressure against piston 61 and this force will be greater than the force against the other side of the piston 61. In this way, the piston 61 can be positively centered in the cylinder 60 by applying equal pressure to both sides of the pistons 61 since when a piston is positioned to the left or right of the center, the effective area and thereby the force against the piston 61 will be greater than in a direction which tends to center the piston.

Movement of the pistons 61 to the right or left limit is smoothly effected by providing pressurized air to the chamber 65 at one end of the piston 61, while the other chamber 66 is pressurized to the atmosphere. Pressurizing and moving cylinders 60 is accomplished by a number of three-way solenoid valves 69, more specifically two valves for each piston 60 and one for each chamber 63 or 64. The valves 69 are connected to the cylinders 60 through passages 70 and are connected via a manifold 71 to the air supply of the vehicle 20 (not shown). Valves 69 also include an exhaust port 72 through which pressurized air can escape to the atmosphere. The solenoid valves 69 are conventional, electrically operated three-way valves which, when actuated by pressurized air flow, block the manifold 71 and exhaust air from the cylinders 60 to atmosphere through the discharge ports 72. Conversely, when the solenoid valves 69 drop, pressurized air from manifold 61 into cylinders 60 and discharge ports 72 are closed. Instructions for energizing and dropping the valves 69 originate from the central processing unit 24 to which they are electrically connected.

The transmission shift operating device 21 further includes a neutral switch 73. The neutral switch 73 mechanically senses the position of the fork devices 62 and, when all 30 are in their center position, indicates that the transmission 11 is in its neutral position. The signal (GN) thus generated is used by the central processing unit 24 in a manner which will be described below.

Information is also provided by the electronic control device 24 through speed scanners 19 and 20. These scanners are in the form of magnetic sensors, the operation of which has been described above and are well known in the art of speed scanning.

The input speed sensor 19 is aligned with one of a number of drive gears 56 on one of the counter-shafts 57 or 57A, senses the speed of the counter-shaft from the transmission 11 and provides this information to the central processing unit 24. Since the counter axis 57 rotates at a fixed speed ratio with respect to the input axis 55, the counter axis speed measurement 40 can also be used with suitable scaling as a measurement of the input speed. The output shaft speed sensor 20 is aligned with a gear 74 on the output shaft 14, senses the speed thereof, and provides this information to the central processing unit 24.

The automatic transmission 10 also includes a counter-axle synchronizer-braking device 22 and a counter-axle-synchronizer-gear device 23 mounted on the front and rear of the transmission 45. The braking device 22 and the gear device 23 cooperate to slow down or accelerate the speed of the counter-shafts 57 and 57A and gears 56 and 58 to ensure that the speeds of the transmission elements (i.e., the gears 58 and claw couplings 59) to be coupled are synchronized or substantially synchronized. The mechanism and theory of its operation is fully described in U.S. Pat. No. 3,478,851 and only a brief description, which emphasizes the difference between this device and the one described herein, which are essentially different from physical and mechanical arrangement will be described below.

The synchronizer braking device 22 operates to decelerate the speed of the counter-shafts 57 and 57A and gears 56 and 58 such that the speed of the particular gear to be coupled or to engage the output shaft 15 by one of the claw clutches 59 is synchronized with the output shaft 14. Braking is accomplished by a conventional disc stacking type clutch device 75 consisting of two sets of interleaved plates 76 and 79.

5 192799

The first set of plates 76 includes a number of inwardly facing keys 77 which couple a number of corresponding keys 78 attached to the input shaft 55. The first set of plates 76 is alternated in the second plate stacker 75 with a second set of plates 79 having a number of outwardly directed keys 80 which couple a number of corresponding keys 81 attached to the housing of the transmission 11. Coaxially disposed with the input shaft 55 and radially aligned with the interleaved portions of the plates 76 and 79, is an annular piston 82 which extends and retracts perpendicular to the interleaved plates 76 and 79 of the plate stack coupling device 75. The annular piston 82 is disposed within an annular cylinder 83 to which pressurized air is supplied through a passage 84 through a single electrically operated three-way solenoid valve 85. The air valve 85 includes a discharge port 86 and when energized it supplies pressurized air to the manifold 71 to the cylinder 83 and blocks the discharge port 86. Conversely, when the solenoid valve 85 drops, the pressurized air flow from the manifold 61 is blocked and the air from the cylinder 83 escapes to the atmosphere through the discharge port 86. By feeding of pressurized air to the cylinder 83 becomes the plate stacking eight The clutch device 75 is depressed, increasing the friction between the plates 76 connected to the input shaft 55 and the plates 79 connected to the transmission housing 11, thereby slowing down the speed of the input shaft 55 and the two left counter-axes 57 and 57A facilitate coupling of the selected claw coupling 59 with one of the driven gears 58.

The counter-axis synchronizer-accelerator device 23 operates much the same as the counter-axis synchronizer-brake device 22, but is activated to accelerate the counter-axes 57 and 57A and the gears 56 and 58. This is necessary when the output shaft 14 and the jaw clutches 59 associated therewith rotate faster than one of the gears 58 to be coupled. The counter-axis synchronizer device 23 includes a plate pack-like coupling device 88 which includes two sets of interleaved plates 89 and 93. The first set of plates 89 includes a number of inwardly directed keys 90 which mate with corresponding keys 91 on collar 92 mounted on the output shaft 14. The second set of plates 93 includes a number of outwardly directed keys 94 which mate with corresponding keys 95 on the inner surface of a gear 58. The gear 58 is coaxially mounted to an output shaft 14 by means of needle or roller lugs in a manner known in the art so that it can rotate relative to the output shaft 14. Radially centered on the interleaved portion of the package-like coupling device 88 is an annular activator 96 which transfers axial force to Your plate package coupling device 88 of an annular piston 98 disposed within an annular cylinder 99. Between the annular activator 96 and the annular piston 98 is a thrust bearing with side treads 97 which facilitates the relative rotation between the annular actuator 96 which rotates with the plate pack coupling device 88 and the annular piston which is prevented from rotating by a locking pin 100 arranged parallel to the axis of the output shaft 14. The retaining pin 100 is attached to the rear of the annular cylinder 99 and extends into a corresponding blind hole 101 in the annular piston 98. Compressed air is supplied to the annular cylinder through a passage 102, extends the annular piston 98 and moves the annular actuator 96 against the plate stack coupling device 88, increasing friction between the two interleaved plates 89 and 93. Thus, the speed of the counter-shafts 57 and 57A can be increased to ensure that the selected driven gear 44 will be synchronized with the associated claw coupling 50 prior to coupling. A three-way electrically controlled solenoid valve 103 connected to the manifold 71 has a discharge port 104. When the valve 103 is energized, the exhaust port 104 is closed, pressurized air flows through the valve 103 and activates the counter-shaft accelerator 23 as just described manner. When the valve falls off, the flow of pressurized air from the manifold 71 is blocked and the air in the annular cylinder 99 can escape to the atmosphere through the discharge port 104. Energy for this synchronizing operation is provided by the kinetic energy of the moving vehicle which is transferred to the transmission 11 by the output shaft 50 14. It is to be understood that the counter-shaft gear 23 must operate in conjunction with the output gear 58A which provides the largest gear ratio, namely the first gear, so that the counter shaft gear 23 will be able to the counter shafts 57 and 57A can be driven to the most necessary speed to achieve synchronization of the transfer gears 58A and the claw clutches 59.

55 Figure 4 shows a table showing the provision and flow of analog and digital signals as well as signal processing in the central processing unit 24. The central processing unit 24 is shown divided into six operational subsystems, indicated by the blocks in Figures 4 and 192799 6 4A . These generally correspond to respective areas of logic and instructional functions. The logic signals listed in Figures 4 and 4A are included in the logic signal glossary, which also includes a brief description of each logic signal. It is to be understood that while Figures 4 and 4A indicate all logic signals for all circuits, the following general description of logic signal generation and its course is introductory and does not describe every logic signal (the logic signal glossary is located at the end of the description).

The central processing unit 24 is divided into six subsystems: a speed and synchronization circuit 112, an accelerator circuit 113, an instruction logic circuit 114, a shift initiation circuit 115, a clutch control circuit 116, and a power source 117. The shift control 26 provides all modes. and manual switching instructions to the central processing unit 24 and because of the close connection with the logic circuit therein, it will be included in the description below.

The logic signals from gear shift control 26 include the four exclusive operating modes, namely automatic (AUTO), manual (MAN), neutral (NEUT) and reverse (REV) as well as two instantaneous 15 instructions, upshift (MUP) and downshift (MDN), used by the driver to instruct the driver to switch to manual mode. These six logic signals are provided to the accelerator circuit 113.

Magnetic sensors provide information to the speed and synchronization circuit 112 regarding the speed of the transmission input shaft 55 or counter axes 57 and 57A, output shaft 14 and 20 motor 13. For the motor 13, the speed and synchronization circuit 112 generates a DC signal at (ES) directly proportional to the axis speed. Two direct current signals are generated for the transmission output shaft 14. The first (OS) is directly proportional to the speed of the output shaft 14. In addition, output shaft signal (OR) is amplified (multiplied) by a factor equal to the numerical value of the gear gear ratio validly selected by the accelerator circuit 113. This provides a DC voltage which is equal to the motor speed when the transmission is in the selected gear with the clutch 12 locked. This signal is hereinafter referred to as the calculated motor speed signal (GOS).

In addition to these analog signals, the speed and synchronization circuit 112 provides several logic output signals, which indicate when the axis speed is greater or less than preset values. These include too high a speed signal (0) derived from the calculated speed of the engine 13 and too low a vehicle speed signal (U) derived from the speed of the output shaft 14.

The rate and synchronization circuit 112 also monitors the difference between the output axis signal (OS) and a calculated output axis signal. This difference represents the actual speed error between the selected output shaft gear 58A and the output shaft 14. When the absolute value of this error exceeds a predetermined limit, an error signal (E) is provided to the torque control circuit 116. When actuated by a signal of the instruction logic circuit 114, the rate and synchronization circuit 112 also supplies the control signals (SB) and (SC) to the appropriate synchronizer 22 and 23.

The primary output of the accelerator circuit 113 is a binary coded information signal 40 (GCN) which identifies the specific gear selected thereby at that time. For neutral and forward gears, a straight three-bit binary code is used. The fourth bit is used for reverse. Another output axis signal (ALARM) from the accelerator circuit 113 signals the driver that an impermissible shift has been requested through the driver shift control 26. The accelerometer also provides, until instructed to forget, signals (LU) 45 and (LD) indicating the direction. indicate the last switch, that is, upshift or downshift. Accelerator circuit 113 consists of a four-bit up / down counter and associated control logic. In response to acceptable valid switch requests, the logic operates a clock input to the counter causing it to count up or down as instructed. In automatic mode (AUTO), shift requests are generated by the shift initiator circuit 115. In 50 manual mode (MAN), the shift request is provided by the movement of the driver shift control 26 to the upshift (MUP) or downshift (MDN) ) position. A neutral instruction (NEUT) from the driver changeover control 26 resets the counter. A reverse command also resets the counter, if valid, and provides the bit-four output.

The instruction logic circuit 114 receives signals such as the binary coded gear set 55 information (GCN), vehicle under speed (U) and the error (E) signals indicating the status of the mechanical automatic transmission 10. Sends based on these input signals these two types of signals, or instructions. The first type are direct signals to the fuel shut-off valve (FV) 15 and the transmission operator 21 (M1 through M6 and MR). These can be regarded as direct instructions for performing a specific mechanical function such as shutting off the flow of fuel to the engine 13 or coupling a given gear ratio in the transmission 11. The second type includes indirect commands which are used to control the operation of other actuators and circuits, mainly the synchronizers 22 and 23 (SE) and the clutch actuator 18 (QD) and (CD). The instruction logic circuit 114 consists of combined logic and delay circuits.

The shift initiation circuit 115 generates logic instructions for upshift (AU) and downshift (AD) in automatic mode. It also provides a downshift release signal (DE) used in both automatic and manual modes. In addition, there are several other input signals such as the last upshift (LU) and the last downshift (LD) signals, which are used either to prevent incorrect shifts or in some circumstances to initiate a shift.

In automatic mode, shifts are initiated by shift initiation circuit 115 based on several factors including: calculated engine speed (GOS), vehicle acceleration, accelerator pedal position 31 (TP), accelerator pedal position change speed, and direction of (LU) and (LD) and the elapsed time since the last switch. With each gear, the position of the accelerator pedal transducer 36 is converted to provide both an upshift and a downshift signal.

The clutch control circuit 116 provides the control signals to the clutch operator 18. Namely, three main operating conditions of the clutch 22 are disengaged, coupled and coupled. Disengage instructions (CD) are sent by the instruction logic circuit 114. In this condition, the clutch control circuit 116 simply passes the control signal (CD) to the clutch operator 18. In the absence of a disengage instruction, the operation of the clutch 25 12 is completely controlled by the clutch circuit 116. There are two clutch modes of clutch 12: start and run. When the calculated engine speed is below a value depending on the accelerator pedal position, clutches are made in start-up mode. Otherwise, pairing is established in a running mode. There are three subdivisions of the run mode clutch depending on the actual speed of the motor 13 which is greater than, less than or equal to the calculated speed of the motor 13. Comparators in the torque control circuit 116 make this distinction. The result of this distinction is provided to the instruction logic circuit 114 for use in the fuel shutdown determination. When the clutch 13 is fully coupled, the high pressure (HP) signal from the high pressure switch 54 places the clutch control circuit in the coupled condition. The power source 117 operates from the vehicle's electrical system to provide the required supply voltage level for the electronics to operate. Typically this will include: a filtered non-stabilized positive battery voltage, and stabilized 8 volt and -6 volt voltage. The latter voltage is obtained from a device such as a DC to DC converter which is known in the art.

As shown in Figures 3 and 5, the speed and synchronization circuit 112 includes a transmission output shaft speed sensor 20 which includes a magnetic pickup 201. The magnetic pickup 201 senses the passing of teeth on a gear 74 shown in Figure 3, which is mounted on the output shaft 14. Acting after the magnetic pickup 201, a tachometer circuit 202 generates a DC voltage on line 203, which is directly proportional to the frequency of the sensor signals and consequently with the rotation speed of the output shaft 14.

Most known tachometer (or frequency to voltage converter) circuits will be suitable. Typically in such circuits, it consists of a comparator operating as a zero transition detector. The comparator output trigger! a pulse generator whose output has a constant width and an amplitude pulse for each triggering. A low-pass filter in the tachometer circuit 202 removes the high-frequency components making the DC signal proportional to the speed of the output shaft 14. Alternatively, a single chip tachometer circuit such as the LM 2917 manufactured by National Semiconductor may be used.

The input axis speed sensor 19 includes a corresponding magnetic sensor 204, which provides an AC voltage signal to a tachometer circuit 205. The output signal from the tachometer circuit 205 on line 206 is in DC voltage proportional to the speed of the input axis 55, 55 and the counter axes 57 and 57A. . Accordingly, the motor speed sensor 17 includes a magnetic sensor 207 that controls a tachometer circuit 208 which provides a DC voltage on a line 209 proportional to the speed of the motor 13.

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The output shaft speed signal on line 203 is amplified by an operational amplifier 212. The gain of the operational amplifier 212 is directly proportional to the input to output shaft gear ratio using a six line to one line multiplexer 213, which receives three-bit binary coded information (GCN) of the accelerator circuit 113 and selects the correct one from the six feedback resistors 214 to 219 so that the ratio of these feedback resistors to input resistance 211 has the operational amplifier 212 a gain factor equal to the input to output gear ratio. The resulting signal represents the speed of the input shaft 55 (GOS) when the gear 11 is in gear selected by GCN. It should also be noted that the signal on line 220 represents the speed 10 of the motor 13 when the control line is locked, that is, the transmission 11 is in gear selected by the GCN and the clutch is engaged. In fact, the signal on line 220 becomes the calculated speed signal of the motor 13 (GOS) in the selected gear.

For several logical decisions, it is necessary to know whether the input shaft 55 (and counter-axes 57 and 57A) on the motor 13 will be subjected to excessive speed upon completion of a switchover. This information (0) is generated by a comparator 221 and its biasing resistors 222 and 223. When the voltage on line 220, which represents the calculated input axis speed (GOS), exceeds the reference voltage created by the biasing resistors 222 and 223, a positive signal (0) is provided by the comparator 221. The overspeed signal (0) on line 224 is available immediately after a new gear is selected and before neither the input shaft 55 and the counter-axes 57 and 57A, nor the motor 13 can be accelerated. As a result, the overspeed speed signal (0) on a line 224 can prohibit switches which, if executed, would result in too overspeed condition. Typically, the overspeed indicator is set to occur at or just above the no-load speed of the engine 13. Accordingly, it is necessary to know whether the vehicle speed is above or below the preset minimum speed. This information (U) is provided by comparator 225 and two bias resistors 226 and 227. The output axis speed signal on line 203 is provided to comparator 225 which provides a positive signal (U) on line 228 when the vehicle speed is below the preset minimum speed . The input shaft voltage signal on a line 206 is fed to an inverting operational amplifier 232 through a resistor 231. The gain of the amplifier 232 is set by a six line to one line multiplexer 233 and associated feedback resistors 234 through 239. The multiple » er 233 receives three-bit binary coded information from the accelerator circuit 113 and selectively connects one of the feedback resistors 234 through 239 corresponding to the gear ratio indicated by the signal (GCN) from the accelerator circuit 113 to the input of the operational amplifier 232. The values of the feedback resistors 232 to 239 is such that for each gear, the gain of the operational amplifier 232 is inversely proportional to the gear ratio between the input shaft 55 (or counter axes 57 and 57A) and the output shaft 14. Thus, the output voltage on a line 241 is proportional with the speed of the main shaft gear 58 corresponding to the gear identified by the gear count signal (GCN) as calculated by dividing the input shaft speed using the appropriate resistor 234 to 239 corresponding to the selected gear ratio in the feedback circuit of the operational amplifier 232. Furthermore, since the operational amplifier 232 is connected as an inverting amplifier, the signal on line 241 will be inverted, i.e. equal to the negative input shaft speed divided by the selected gear ratio.

The output of the inverting operational amplifier 232 is fed through an insulating 45 resistor 242 and the output of the tachometer circuit 202 on a line 203 is fed through an insulating resistor 243 to an amplifier 244. A feedback resistor 245 is connected between the input and the output of the amplifier 244. The output of the amplifier 244 on a line 246 represents the difference between the positive actual speed of the output shaft 14 as monitored by the scanner 20 and the negative calculated speed of the output shaft provided by the inverting operational amplifier 232-. multiplexer 233 combination that receives a signal from the input shaft speed sensor 19. When the signal on the line 246 is an error signal directly representing the relative difference of the speed of the clutch transmission components, namely the main shaft gear 58, identified by the gear count code (GCN ) i n toothed relationship with the input shaft 55 and the corresponding claw coupling 59 rotating with the output shaft 14.

55 The error signal on line 246 is then fed to a complementary pair of voltage comparators 247 and 250. The output of voltage comparator 247 becomes positive when the speed of the selected main shaft gear 58 exceeds the actual speed of the output shaft 14 by an amount. equal to the reference level induced by the voltage dividing resistors 248 and 249. Accordingly, the output of the comparator 250 will become positive when the speed of the selected main shaft gear 58 is less than the actual speed of the output shaft 14 by an amount equal to the reference levels set by the voltage divider resistors 251 and 252. These reference 5 levels are set equal or just below the acceptable speed error, that is, the relative difference between the rotational speed of the selected main shaft gear 58 and the output shaft 14, for coupling the claw couplings 59. Typically, this will in the or the magnitudes are 25 revolutions per minute or less.

The output signals of voltage comparators 247 and 250 are connected as shown in Figure 10 to an OR gate 253 and two AND gates 254 and 255. The OR gate 253 provides a logic error signal (E) to the logic circuit 114 indicating that a speed error greater than the acceptable level exists between the transmission elements. This signal (E) is used by the instruction logic circuit 114 to control the sequence of the switching process.

It is essential that attempts to synchronize the transmission 11 only occur when certain conditions are met, including the fact that the transmission 11 is in neutral with the clutch 12 disengaged. When all conditions are met and it is desired to synchronize the transmission 11, the instruction logic circuit 114 provides a sync enable instruction (SE) on a line 256 to AND gates 254 and 255. When the sync enable instruction (SE) is present and there is a positive signal from either comparator 247 or comparator 250, 20, AND gates 254 or 255 will provide the necessary control signals (SB) or (SC) to the synchronizer braking device 22 or the buffers 257 or 258 through the buffers 25 or 25. synchronizer accelerator 23 as required by the magnitude and direction of the input-output speed error.

The speed and synchronization circuit 112 further includes a complementary pair of comparators 261 and 262 controlled by the actual motor speed (ES) on line 209 and the calculated motor speed 25 (GOS) on line 220. The signals ES and GOS are provided by comparators 261 and 262 connected by four scaling resistors 263, 264, 265, and 266 as shown in Figure 5. Comparator 261 supplies too high a motor speed signal (EH) to the instruction logic circuit 114 and clutch control circuit 116 indicating the actual speed of the motor 13 is above the calculated motor speed. Comparator 262 provides motor speed signal (EL) too low to clutch control circuit 116, indicating that the actual motor speed is below the calculated motor speed value. In Fig. 6, the accelerometer circuit 113 is shown. The main function of the accelerometer circuit 113 is to select the correct gear ratio of the transmission 11 in response to the logic signals provided thereto and generate a binary coded signal (GCN) representative of the selected gear ratio for use by the other circuits.

35 The accelerator circuit 113 receives signals from the speed and synchronization circuit 112, the shift initiation circuit 115, the ignition switch 25, the driver shift control 26, the throttle switch 34, the throttle switch 35, the brake switch 38 and the neutral switch 73. These signals are applied to a field-programmable logic array 301 and provide the information on which the gear selection is based. Discrete logic elements can also be used. Because of the number of inputs to the field-programmable logic array 301, two additional logic devices, namely two read only memories (ROMs) 302 and 303, are used to pre-encode the information received from the shift initiator circuit 115 and the driver shift controller 26, respectively. The logic instructions from the field-programmable logic array 301 and the ROMs 302 and 303 are contained in the logic rules (which are also included after the description). In principle, logic devices 301, 302 and 303 are programmed to: limit the binary coded gear count information to the number of forward gears contained in the transmission 11; selecting a new gear in automatic mode in response to the request from the shift initiating circuit 115; selecting a new gear in manual mode in response to the explicit driver instructions 50 through the driver shift control 26; choosing either neutral or reverse in response to explicit driver instructions; starting a shift to a starting gear, normal first gear, in automatic mode; forbidding the selection of a gear in any mode which will result in too great a speed of the motor 13; prohibiting the selection of a new gear when certain incorrect conditions are detected in the system; and providing turn-on and turn-off sequences.

The binary coded gear count information (GCN) is generated by a clock pulse oscillator 305 and an up counter 306, which are controlled by logic outputs from the field programming 192799 logic logic 301. The field programmable logic array 301 provides a clock clearing signal (CLE) on a line 304 which activates the clock pulse oscillator 305, a logic signal (UP) on a line 307 which has the positive or true signal when a upshift is instructed and zero or false when a downshift is instructed and a logic signal (RESET) on a line 308, which resets the 5 up counter 306 to zero. The clock pulse oscillator 305 provides the clock pulses which typically have a 100 Hz repetition rate. The clock frequency is not critical. It should be low enough for various gears, mainly for the speed and sync circuit 112 and the shift initiate circuit 115 to respond to the new gear selection. At the same time, it must be sufficiently fast to realize the correct gear selection before the mechanical elements of the system can react. The binary coded gear count information (GCN) is carried on four lines 309, 310, 311 and 312. The up-down counter 306 adds when pulsed by the clock pulse oscillator 305, while a positive signal (UP) exists on line 307. Conversely the up-down counter counts down when a beat is pulsed by the clock pulse oscillator 305 when there is no signal on line 307. The current forward gear selected by the accelerometer 15 circuit 113 is represented in binary code on the three lines 309, 310 and 311. A reset signal (RESET) on line 308 resets update counter 306 and the signals on three lines 309, 310 and 311 become zero. The field programmable logic array 301 also provides a logic signal (SR) in the fourth gear line 312 corresponding to the reverse gear. Each of lines 309 through 312 shown in Figure 6 carries one bit of the binary coded information (GCN). The following table 20 indicates the binary code used to indicate the neutral, forward and reverse gears of transmission 11.

ACCELERATION SETTING (GCN) 25 Gear selection Logic Binary bit line (figure 6) symbol 309 310 311 312

Neutral S0 0 0 0 0 30 First S1 1 0 0 0

Second S2 0 1 0 0

Third S3 1 1 0 0

Fourth S4 0 0 1 0

Fifth S5 1 0 1 0 35 Sixth S6 0 1 1 0

Reverse SR 0 0 0 1

A delay device 319 provides a signal to a enable input of the field programmable logic array 301. This signal is initiated at the rise of the supply voltage to an acceptable level and persists for a fraction of a second thereafter. If the delay 319 signal is present, the outputs of the field-programmable logic array 301 are disabled. In this condition, the logic levels of the outputs of the field-programmable logic array 301 are determined by the resistors connected from these outputs to either 45 ground or supply voltage levels.

The arrangement of resistors 313 through 317 is such that when the counter 306 is reset, the oscillator is not energized and there is no alarm. The reverse code line 312 is also reset to the logic zero. In this way, the accelerometer 306 is always forced to a neutral choice after being turned on.

A lockout 321 provides a signal which ensures that the up-down counter 306 will count only one step in response to any explicit up or down request by the driver shift control 26. A signal on line 322 is normally set and held high by the presence of either the auto (AUTO) or the manual (MAN) signal from the read only memory 303. When an up (MUP) or a back (MDV) changeover is requested through driver changeover control 26, the 55 signal on line 312 to be absent. The absence of the signal on line 322 together with a clock pulse on line 323 sets the output of the latch 321 (ONE) low, preventing further switching. Accordingly, after any request to shift up or down, the driver should allow the 11 192799 driver shift control 26 to return to the manual or auto mode, by setting ONE high before another shift request will be accepted.

The accelerator circuit 113 also generates logic signals (LU) and (LD), which indicate the direction of the last shift. The locks 333 and 336 store in their output lines 5 and 334 and 337, respectively, the signal present on their data inputs, namely lines 307 and 339A at the time when the input lines 333 go higher. The data input to 333 is the UP signal on line 307. The inverter 339 is connected between the UP signal line 307 and data input from locker 336. Thus, the data input to the locker 336 will be positive if the UP signal is not positive.

The output (LU) of the latch 333 on line 334 will go positive when counter 306 performs a 10 UP count. Accordingly, the output (LD) of lockout 336 on line 337 will go positive when counter 306 counts down. The last upshift (LU) signal on line 334 will remain positive until either counter 306 counts down or is reset by a signal on reset line 335, as will be described next. Accordingly, the last downshift signal (LD) on line 337 once set will remain positive until either counter 306 performs an UP count or until it is reset by a signal on the reset line as will also be described below.

The clock pulse (CP) signal on line 323 is also applied to delay device 325. Delay device 325 provides a pulse that starts simultaneously with the clock pulse and continues for about 0.5 seconds. This extended clock pulse is then applied to the input of an inverting amplifier 326. The inverting amplifier 326 provides a signal that is true or high when the extended clock pulse provided by the delay device 325 is not present at its input. The output of the inverting amplifier 326 is supplied as an input of a triple input AND gate 327. The triple input AND gate 327 also receives a switchover reset (SR) signal on a line 331 of the switchover initiator circuit 115. The third input from the triple input AND gate 327 is powered by the output of a lockout 333. The lockout 333 provides a final upshift (LU) signal on a line 334 to the switch initiation circuit 115 and the triple input AND gate 327 which is positive or true if the last changeover was in the upshift direction. The signal remains positive until a downshift instruction is given. When a final upshift signal (LU) is present on line 334, a switchover reset (SR) signal is present on line 331, and no delayed clock pulse is present at the input of inverting amplifier 326 so that its output will be positive. triple input AND gate 327 provide a positive signal on a reset line 335 to the latch 333 for resetting the output of the latch to a zero or a zero state.

A corresponding circuit resets the last downshift logic signal (LD) which is also applied to the switch initiator circuit 115. A second triple input AND gate 328 is also supplied with the inverted delayed clock pulse output from the inverting amplifier 326. In addition, the triple input receives AND gate 328 an inverted switchback return signal (SR) from an inverting amplifier 332 and the last downshift signal (LD) from the latch 336 on a line 337. When these three conditions are true, the 40 triple input AND gate 328 provides a positive signal on line 329 which resets the output of the latch 336 to a zero or zero state.

In Fig. 7, an instruction logic circuit 114, which primarily controls the operation of the clutch 13, the fuel shut-off valve 15, and the shift solenoid 69, is shown. In all cases, the operation of these components results from a determination by the instruction logic circuit 114 that the transmission 45 is not in proper gear. This determination is made in two ways: first, the excitation signal to the solenoid valves 69 is in accordance with the gear just selected by the accelerator circuit 113, and second, the ratio of the speed of the output shaft 14 to the speed of the input shaft 55 is equal to the gear just selected by the accelerator circuit 113.

50 The first determination is made as follows: the binary acceleration code information (GCN) of the accelerator circuit 113 is supplied to a four bit latch 401. The output of the four bit latch is supplied to a read only memory (ROM) 402 which is the binary acceleration code decodes into a specific signal for each solenoid valve 69 associated with each gear. A plurality of amplifiers 404 amplify the specific signal for each solenoid valve 69 from the read-only memory 402 to a level high enough to energize the solenoid valve 69. The binary gear code information (GCN) to the four-bit lock 401 is passed to the outputs of the lock 401 only when the gear 11 is about to enter gear 192799 12. A logic comparator 403 compares the inputs and outputs of the lock 401 and a logic inverter 405 provides a signal on the line 406 when the input and output codes of the lock 401 do not match. Thus, if at any time the gear selected by the accelerator circuit 113 does not match the gear engaged or attempted to be coupled by the transmission 11, a signal is provided.

The second method of determining that the transmission 11 is not in proper gear is by comparing the speeds of the input shaft 55 and the output shaft 14. The speed and synchronization circuit 112 generates an error signal when the actual speed of the output shaft 14 differs from the calculated speed of that shaft obtained by dividing (or multiplying) the measured speed of the input shaft 55 by the current coupled gear ratio.

The error signal (E) from the speed and synchronization circuit 112 and the signal on line 406 are applied to an OR gate 407, the output of which controls the setting input of an RS flip-flop 408. When one of these provisions indicates, therefore, that the transmission is not coupled in the selected gear, flip-flop 408 is set and provides a switch-15 sequence instruction on a line 409. RS flip-flop 408 is reset by a signal from AND gate 416 on line 417 .

The instruction logic circuit 114 also provides a synchronization clearing instruction (SE) on the line 256 which controls the operation of the synchronizer braking device 22 and the synchronizer accelerating device 23 via the speed and synchronizing circuit 112. The synchronization clearing instruction (SE) on the line 256 is provided by a triple input AND gate 411. The output of the triple input AND gate 411 becomes positive when there is a switching sequence instruction on a line 409 of the RS flip-flop 408, a signal (LP) on a line 412 of the low pressure switch 53 that the clutch 12 is disconnected and the signal (GN) on a line 413 of the transmission neutral switch 58 indicates that the transmission 11 is in the neutral position.

The error signal (E) from the speed and synchronization circuit 112 is also applied to an inverting amplifier 414 and thus indicates a signal on line 415 that no error signal is present in the input of amplifier 414 and vice versa. This inverted error signal on line 415 and the synchronization enable signal (SE) on line 256 are both applied to a dual input AND gate 416. When both inputs to AND gate 416 are positive, this provides a logic signal on a line 417 at both reset inputs of the RS flip-flop 408 and a delay device 418. The delay device 418 immediately passes the logic signal on line 417 to an input of a dual input AND gate 419 when the signal on line 417 becomes positive and continues to provide a signal to the input of the dual input AND gate 419 for about 1/10 second after the signal has ceased on line 417. Thus, the signal on line 35 between the delay switch 418 and one input of the dual input AND gate 419 represent a condition of the system when both there is no error signal (E) from the speed and synchronization circuit 112 and the presence of a synchronization enable signal. (SE) on the line 256. Furthermore, the signal on the line between the delay circuit 418 and one input of the dual input AND gate 419 continues for 1/10 of a second after one of the above 40 conditions ceases. to exist.

The too low speed signal (U) from the speed and synchronization circuit 112 is applied to an inverting amplifier 422 and the output indicating the lack of too low speed signal is connected to the other input of the dual input AND gate 219. The Thus, the output of AND gate 419 represents the condition of the system in which a logic signal 45 exists on the line between delay circuit 218 and an input of the dual input AND gate 419 and the output of inverting amplifier 422 is positive, indicating that there is no too low speed condition.

The signal (TS) from the accelerator pedal switch 34 is applied to an inverting amplifier 423. Thus, the output signal of the inverting amplifier 423 becomes positive when the driver's foot is not on the accelerator and the accelerator switch 34 is not closed. The signal from the inverting amplifier 423 is applied to one input of a dual input AND gate 424. The under speed signal from the speed and synchronization circuit 112 is applied to the second input of the dual input AND gate 424. The output signal of Thus, the dual input AND gate 424 is positive when both an under-speed condition of the vehicle is signaled by the speed and synchronization circuit 112 and the accelerator pedal switch 34 and inverting amplifier 423 provide a signal characteristic of the fact that the driver's foot is not on the accelerator.

13 192799

Three signals, that of the output of RS flip-flop 408 on line 409, the output of the double input AND gate 419 and the output of the double input AND gate 424 are fed to a triple input OR gate 425. OR gate 425 provides a positive output when at least one of the three inputs is positive. The output of the triple input OR gate 425 is the coupling decoupling signal (CD) and as such is applied to the coupling control circuit 116 and the amplifier 426. The amplifier 426 is equal to the amplifier 404 and increases the output of the triple input. OR gate 424 to a level high enough to directly control the rapid dump solenoid 52 in the link operator 18.

Normal upshifts will occur with the throttle 31 open. Once clutch 12 is disengaged 10, motor 13 will tend to accelerate to its no-load controlled speed. For this reason, throttle dimming is provided during a shift to reduce the speed of the motor 13 to the average speed it will assume after the shift is completed. The comparator 261 and 262 in the acceleration and synchronization circuit 112 indicate when the actual speed1 of the motor 13 is greater or less than the calculated motor speed. The overspeed motor speed signal 15 (EH) from comparator 261 is applied to both first inputs of a triple input AND gate 428 and an inverting amplifier 429. The triple input AND gate 428 is also supplied with a signal from the inverting amplifier 422 indicating the lack of too low speed condition in the motor and the switching sequence instruction on line 409 generated by the RS flip-flop 408. When all three inputs of the triple input AND gate 428 are positive, it a positive output which is applied to the set input of an RS flip-flop 430. The output of the inverting amplifier 429, which is positive when no too high motor speed signal (EH) is fed to one input of a double input OR gate 431. The second input of the dual input OR gate 431 is connected to the under speed signal (U) which supplies the inverting amplifier 422 and the d ubbele input AND gate 419.

Thus, if there is or is not too high a motor speed signal (EH) indicated by the presence of an output from the inverting amplifier 429 or there is a too low speed signal (U), there will be a positive output from the dual input OR gate 431 which is fed to the reset input of the RS flip-flop 430. Thus, the output of the interlock or RS flip-flop 430 becomes positive and remains positive when the setting input is positive due to the fact that all inputs of the triple input 30 AND port 428 are positive. The latch or RS flip-flop 430 output ceases when the reset input of the latch flip-flop 430 is positive due to one or both of the inputs of the dual input OR gate 431 being positive . The output of the latch or RS flip-flop 330 is applied to one input of a dual input AND gate 432. The second input of the dual input AND gate 432 is controlled by a signal (IGN) indicating that the ignition switch is in the power is on. Therefore, when both inputs of the latch or RS flip-flop 430 and the signal (IGN) of the ignition switch 35 are positive, a positive output will be generated by the dual input AND gate 432 and amplified by operational amplifier 433. The output of the operational amplifier 433 will be a sufficient level to control the fuel shut-off valve 15 and supply fuel to the engine 13.

40 In Figure 8, the switching initiation circuit 115 is shown. The shift initiation circuit 115 provides a shift enable signal based on the gas tip (TP) versus the calculated engine speed (GOS).

An amplifier 501 receives a signal from the accelerator pedal position transducer 36 and generates the base throttle modulated shift point signal for downshifting. A feedback resistor 502 45 is connected between the input and output of the amplifier 501. The gain of the amplifier 501 is adjusted by the selective introduction of one of a number of resistors 504 to 510 into the feedback circuit of the amplifier 501 using a electronic switch 503. Resistors 504 through 510 are scaled proportionally to generally represent the gear ratios available in transmission 11. Electronic switch 50 503 receives the binary coded gear count information (GCN) from the accelerator circuit 113 which is currently selected. represents acceleration. The electronic switch 503 connects one of a number of resistors 504 to 510, which represent the currently selected gear between ground and the feedback circuit of the amplifier 501. Thus, the gain of the amplifier 501 is controlled by the feedback resistor 502 and the resistance selected by the electronic circuit 503 such that the signal on the line 511 represents the signal of the accelerator pedal transducer 36 scaled by a value determined by the resistance corresponding to the gear selected by the accelerator circuit 113. The signal on the line 192799 14 511 is connected to the first input of a comparator 512 through an isolation and scaling resistor 513. Also connected to the first input of comparator 512 is the last upshift signal (LU) of the accelerator circuit 113. This signal is applied to a comparator 512 via an isolation s and scaling resistance 514.

The signal (TP) from the accelerator pedal position transducer 36 is also applied to the input of an amplifier 515 through a capacitor 516. A feedback resistor 517 is connected between the input and output of the amplifier 515. Thus connected, the amplifier 515 acts as a differentiating amplifier whose output on line 518 is proportional to the rate of change of the throttle converter 36. The polarity of the amplifier 515 is such that the output is positive when the rate of change of the position of the transducer 36 decreases and negative when the rate of change of the position of the transducer 36 increases. The output of the differentiating amplifier 515 is also applied to the first input of comparator 512 through a scaling and isolation resistor 519.

A fourth signal representing the rate of change of the output shaft speed is also applied to the first input of the comparator 512. The signal of the speed and synchronization circuit 112 represents the speed of the output shaft 14 and is supplied to an amplifier 510 through a capacitor 521. A feedback resistor 522 is connected between the input and the output of the amplifier 520. Thus connected, the amplifier 520 functions as a differentiating amplifier and thus the signal on line 523 represents the rate of change of the output axis speed. The output of the differentiating amplifier 520 is inverted, that is, when the speed of the output shaft 14 increases, the output of the differential amplifier 520 is negative and vice versa. The signal on line 523 is then applied to comparator 512 through isolation and scaling resistor 524.

A signal (GOS) from the speed and synchronization circuit 112 representing the calculated speed of the motor is applied to the second input of the comparator 512 on a line 525. When the signal on the line 525 representing the calculated speed of the motor represents (GOS) is less than the sum of the voltages provided by the first input of comparator 512 through the scaling and isolating resistors 513, 514, 519 and 524, an automatic reset signal (AD) is generated at the output of the comparator 512. This downshift request signal (AD) is used by the accelerator circuit 113 to compose a downshift instruction.

A corresponding circuit is used to generate an upshift request (AU) signal. The signal (TP) from the accelerator pedal position transducer 36 is also applied to an amplifier 531. A feedback resistor 532 is connected between the input and output of the amplifier 531. A number of individually selectable resistors 533 through 538 and an electronic switch 539 are also connected in the feedback circuit of the amplifier 531. The electronic switch 539 receives binary coded gear count information (GCN) from the accelerometer circuit 113 indicating the gear selected by that circuit and connects the resistance corresponding to the currently selected gear in the feedback circuit from the accelerator circuit 113. amplifier 531. The gain of the amplifier 531 is thus selected by electronic switch 539 in accordance with the gear applicable selected by the accelerometer circuit 113 and the signal on a line 540 represents the position of the throttle transducer 36 as modified by d The amplifier 531. The signal on line 540 is applied to a first input of a comparator 541 through an isolation and scaling resistor 542. Also summed at the first input of comparator 541, the last downshift (LD) signal from the accelerator circuit 113 This signal (LD) is applied to a line 543 through scale and isolation resistor 544.

45 The signal (GOS) on the line 525, which represents the calculated motor speed of the switching and synchronizing circuit 112, is applied to the second input of the comparator 541. When the signal (GOS) on the second input of the comparator 541, which represents the calculated motor speed greater than the sum of the signals on the first input of comparator 541, an automatic upshift signal (AU) generated by comparator 541 and 50 is applied to accelerator circuit 113.

The shift initiator circuit 115 further generates a downshift enable (OE) signal which allows or prohibits the requested shifting based on a comparison of the maximum allowable downshift speed for each gear with the calculated motor speed (GOS). An electronic switch 550 and a plurality of proportional scale resistors 551 through 556 provide a voltage 55 on a line 557 in proportion to the currently selected gear as indicated by the binary coded gear count information (GCN) provided by the electronic switch 550 through the accelerator circuit 113. The electronic switch 550 receives a constant voltage on line 15 192799 558 and selects one of the number of resistors 551 through 556 corresponding to the current gear selected by the accelerometer circuit 113 and provides a voltage on the line 557 determined by the current gear selected. . A resistor 559 is connected between line 557 and ground. The voltage on line 557 is applied to one input of a two-input comparator 560 and the other input of comparator 560 is controlled by the signal (GOS) on line 525, which represents the calculated motor speed. The voltage on line 557 is modified by the presence or absence of the various additional signals. The signal (RTD) from the gas-on-the-shelf switch 35 is summed to the signal on a line 557 by a scaling resistor 562. Accordingly, the last upshift signal (LU) is scaled by a resistor 564 and summed on the 10 line. 557. Finally, a signal (MAN) of the manual position of the driver changeover control 26 or a signal (BS) of the brake switch 38 is applied through the diodes 565 and 566 respectively through a resistor 567 and on the line 557. The presence or absence of signals from throttle on-the-board switch 35 (RTD), the last upshift signal (LU) from the accelerator circuit 113, the brake signal (BS) from the brake switch 38 with the drivers' manual (MAN) signal -15 switching control 26 are all summed on line 557 and thus modify the operating point at which a downshift release (DE) instruction is generated by comparator 560. When the signal (GOS) on line 525 representing the calculated motor speed represents less than the sum of the signals on line 557, a downshift release (DE) signal is generated by a comparator 560.

The signal from the accelerator circuit 113 is also supplied to an electronic switch 570. The electronic switch 570 receives a constant voltage on line 571 and provides a scaled voltage on line 572 directly proportional to the currently selected gear as indicated by the binary coded gear adjustment information. (GCN) provided by the accelerator circuit 113. This is accomplished, as already described by choosing one of a number of scale resistors 573 through 578 with value proportional to the gear ratios of the transmission 11. Throttle-up signals the plank switch (RTD) which is scaled by a resistor 579 and of a line 543, carrying the last downshift signal (LD) of the accelerator circuit 113 which is scaled via a resistor 580, is also summed on the line 572 The other input of comparator 582 is controlled by the calculated m engine speed signal (GOS) on line 525. When the signal on line 525, which represents the calculated engine speed, is greater than the signal on line 572, which is the current selected gear ratio as modified by the on-the-throttle switch 35 signal (RTD) and the last downshift signal (LD) on the line 543 of the accelerator circuit 133, the comparator 582 generates an upper limit signal (UL).

Finally, the accelerator pedal position transducer 36 also provides a signal (TP) to an input of a comparator 583 through a scale and isolation resistor 584. The signal (GOS) on line 525 represents the calculated motor speed and is also applied to this input of comparator 583 through a scale isolation resistor 585. The other input of comparator 583 is grounded. The signal (GOS) on line 525 represents the calculated motor speed and is added to the signal (TP) from the accelerator pedal transducer 36 and when the input signal on comparator 583 exceeds a threshold, it provides a shift-reset (SR) signal for the lock 333 and 40 336 in the accelerator circuit 113 which generates the last upshift signal (LU) and the last downshift signal (LD).

In Figure 9, the clutch control circuit 116 is shown. The clutch control circuit 116 receives a signal (ES) from the speed and synchronization circuit 112 on the line 601 representing the motor speed 13. This signal is applied to an inverting amplifier 603 through a capacitor 452. Thus connected, the inverting amplifier 603 acts as a differentiating amplifier and provides an output representing the change speed of the motor speed. The gain of the differentiating amplifier 603 is controlled by a number of resistors 604 through 609 and an electronic switch 610 connected in feedback circuit of the amplifier 603. The electronic circuit 610 receives the binary coded gear count information (GCN) from the gear 50 counter circuit 113 and selects the resistance from the number of resistors 64 through 69. The signal on line 611 represents the inverted change in motor speed acceleration scaled by a value determined by the gear selected in effect by accelerator circuit 113. The signal on line 611 is applied via a resistor 612 to amplifier 613. The amplifier 613 is connected as an inverting amplifier and consequently the output of the 55 amplifier 613 represents the positive change speed of the motor speed. A feedback resistor 615 is connected between the input and output of amplifier 613, and the value of resistors 612 and 615 are set such that the gain of amplifier 613 is one. The signals on lines 192799 16 614, representing the positive speed change of the motor speed and the signal on the line 611, representing the inverted or negative change speed of the motor speed, are each applied to a multiplexer 616 through resistors 617 and 618. The motor speed ( ES) on line 601 is supplied to multiplexer 616 through a scaling resistor 619.

The clutch control circuit 116 also receives a signal (TP) from the accelerator pedal position transducer 36 on a line 620. The signal from the accelerator pedal position transducer 36 is modified by resistors 621 through 623 and a zener diode 624 and applied to the input of an inverting amplifier 625. Also associated with inverting amplifier 625 is a resistor 626, which provides a positive offset voltage to the input of inverting amplifier 625. The magnitude of the offset voltage provided by the resistor 626 is equal to or slightly greater than the voltage provided by the accelerator pedal transducer 36 when the motor 13 is in neutral. A feedback resistor 627 is connected between the input and output of the inverting amplifier 625 and controls the gain factor of the amplifier 625. Zener diode 624 has an amplified voltage equal to 60-70% of the voltage applied by the accelerator pedal transducer 36 with the accelerator pedal fully depressed. At 15 accelerator pedal settings below the zener voltage of diode 624, the voltage at the junction of resistors 622 and 623 will be zero. Thus, the output voltage of the inverting amplifier 625 will increase linearly with respect to the position of the accelerator pedal transducer 36. The gain of the amplifier 625 is set to the value of the resistor 627 and 621 plus the offset voltage provided by the resistor 626. When the voltage on line 620 generated by the accelerator pedal transducer 36 20 is greater than the zener voltage of the zener diode 624, the difference between the accelerator pedal voltage and the zener voltage will occur as an additional input signal to the amplifier 625 through the resistor 622. The signal at the output of the inverting amplifier 625 on line 628 increases negatively and linearly with the increased accelerator pedal position until the zener diode 624 begins conducting at which time the slope of the line indicating this linear negative increase changes.

The negative accelerator pedal position signal on line 628 is also fed to another inverting amplifier 630. The inverting amplifier 630 associated with its input resistor 631 and feedback resistor 632 is set to have the gain factor 1 and inverts the inverted accelerator pedal position signal (TP) again. by inverted amplifier 625 so that at the output of inverting amplifier 630 on line 633, the signal increases positively as the accelerator pedal position signal (TP) increases. Furthermore, as was the case with the inverted signal on line 628 when diode 624 begins to conduct, the line representing the relationship between accelerator pedal position and line 633 changes. The signal on line 633 is also applied to one input of the double input comparator 635 through a resistance divider consisting of a resistor 636 connected to one input of the comparator 635 and a resistor 637 connected to that same point to ground.

A second input from the dual input comparator 635 receives a signal (GOS) on a line 638 representing the calculated motor speed from the speed and synchronization circuit 112. When the calculated motor speed signal (GOS) on line 638 is less than the signal provided to the dual input comparator 635 by inverting comparator 630, a positive signal is generated by comparator 635 and appears on line 640. A positive signal on line 640 makes 40 which will be indicated as a mode A coupling cycle by coupling 12. The mode A coupling cycle will be described in the following.

Coupling control circuit 116 also receives a coupling decoupling signal (CD) from instruction logic circuit 114 on a line 641. This signal is applied to an input of a dual input gate 642. The second input of dual input OR gate 642 receives a 45 signal (HP ) on a line 643 of the high pressure switch 54 associated with the coupling 12. When the coupling release signal (CD) on the line 641 or the high pressure signal (HP) on the line 643 is positive, the dual input OR gate 642 a positive signal on a line 644 to multiplexer 616. The coupling decoupling signal (CD) on line 641 is also applied to an inverting amplifier 660.

Two additional signals are applied to the clutch control circuit 116 through the speed and synchronization circuit 112. These are the overspeed motor speed (EH) signals supplied on a line 646 and the overspeed motor speed signals (EL) supplied on a line 647. The motor speed signal (EH) too high is positive when the speed of the motor 13 as sensed by the motor speed sensor 17 is greater than the speed of the input shaft 55 of the transmission 11 as sensed by the 55 transmission input speed sensor 19. The motor speed signal ( EL) is positive when the speed of the motor 13 as sensed by the motor speed sensor 17 is less than the speed of the input shaft 55 of the transmission 11, as sensed by the transmission input speed sensor 19.

17 192799

The overspeed motor speed signal is applied to one input of a dual input AND gate 648. The second input of the dual input AND gate 648 is controlled by the output of the inverting amplifier 649. The input of the inverting amplifier 649 is controlled by the mode A signal on line 640. The output of the inverting amplifier 649 is positive when a 5 mode A signal does not exist on line 640 and vice versa. It follows that the output of the dual input AND gate 648 indicated mode B on line 650 is positive when both the mode A condition does not exist and an excessive motor speed signal (EH) does exist. The mode B signal on line 650 is also applied to the multiplexer 616. The output of the inverting amplifier 649, which is positive when a mode A signal is not present, is also applied to an input of a dual input EN- gate 651. The second input of the dual input AND gate 651 is controlled by the motor speed signal (EL) too low on line 647. Thus, when no mode A signal is present and motor motor signal (EL) is too low, the dual input AND gate 651 a positive mode C signal on line 652. The mode C signal on line 652 is also supplied to multiplexer 616.

Before proceeding with the description of the clutch control circuit 116, the meaning of the four clutch torque modes, namely mode A, mode B, mode C and mode D, will be explained.

These modes refer to the four possible conditions under which the link can be called to link. Mode A represents a coupling torque condition in which the output shaft 14 does not rotate or rotate slowly. Mode B indicates the condition in which the motor 13 is operating at a speed greater than the speed of the input shaft 55 of the transmission 11. Under these clutch conditions, the motor will usually slow down when the clutch 12 is coupled. Mode C clutch refers to those conditions in which the speed of the motor 13 is slower than that of the transmission input shaft 55. Here, the speed of the motor is usually greater when the clutch 12 is coupled. The fourth clutch torque mode mode D exists when the vehicle is moving and the engine speed and the input shaft speed are equal or approximately equal, ie when none of the modes A, B or C exist.

The multiplexer 616 receives the mode A signal on line 640, the mode B signal on line 650 and the mode C signal on line 652, and the prohibit signal on line 644. These are the control inputs to multiplexer 616. When the prohibition signal on line 644 is zero, multiplexer 646 connects one of its 30 inputs to lines 654, 655, 656, or 684 at its output on line 686. A positive mode A signal on line 640 connects line 654 to line 686. A positive mode B signal on line 650 connects line 655 to output line 686. A positive mode C signal on line 652 connects line 656 to output line 686. In the absence of a mode A signal on line 640 , a mode B signal on line 650 and a mode C signal on line 652, multiplexer 616 connects line 685 to output line 686. This corresponds to a mode D condition. When the prohibition signal on a line 664 is positive, the multiplexer 616 disconnects all inputs from the output line 686. Thus, in mode A couplings, the positive rate of change of the engine speed signal on line 614 through a resistor 617, a motor speed (ES) on line 601 through a resistor 619, and the negative throttle signal on a line 628 through a resistor 629 are all connected to the output line 686 of the multiplexer 616. In mode B couplings, the positive 40 speed change of the motor speed on line 614 through resistor 618 and the positive throttle signals on line 633 through a resistor 634 are all connected to output line 686 of the multiplexer 616 In mode C couplings, the negative rate of change of the engine speed signal on line 611 through a resistor 659 and the positive throttle signal through a resistor 645 are all connected to the output line 686 of the multiplexer 616. In mode D couplings, the positive supply voltage is applied through 45 a resistor 684 connected to the output line 686 of the multiplexer 616.

An amplifier 660 has a feedback resistor 661 connected from its output on a line 662 to its negative input on a line 686 which is also the output of multiplexer 616. In this way, the amplifier 660 and the associated resistor 661 act as an inverting amplifier . The positive input of the amplifier 660 is connected to the coupling decoupling signal 50 (CD) on line 641. Except when the coupling decoupling instruction (CD) is present, this input will be at a ground potential. During coupling, the output of the amplifier 660 on a line 662 will be the weighted sum of the input signals, the weighting being proportional to the ratio of the feedback resistor 661 with an input resistor connected to the amplifier 660 via multiplexer 616.

The signal on line 662 is applied to an input from dual input comparators 664, 55, 665, 666, and 667. Voltage divider resistors 670, 671, 672,673, 674, and 675 provide various positive and negative voltages from the positive and negative voltage sources and provide voltage set points for comparators 664 through 667. The outputs of comparators 664 through 192799 18 with 667 control amplifiers 680 through 683, which in turn control supply valves 51 and 50 and fill valves 47 and 48. When the signal on line 662 is less than the lowest setpoint voltage, namely that voltage associated with the operation of a comparator 665 and the fine discharge valve 50 and the comparator 666 and the fine fill valve 47, all comparator outputs will be zero and all clutch-5 air valves off to be. When the coupling error signal deviates from zero and increases in either the positive or negative direction of the set point of comparators 664 through 667, one or more of the comparators will provide outputs and control the corresponding coupling air valves.

Mode A clutches usually occur when the vehicle starts from or is about to rest. In this condition, the output of amplifier 660 on line 662 will be equal to the weighted sum of the accelerator pedal position (TP) signal minus the engine speed signal and minus the change speed of the engine speed. When the combination of motor speed and motor acceleration is less than the weighted pedal position signal, the output signal of the amplifier 660 will operate positively and depending on the size, the comparators 665 or 665 and 664 will operate causing the fine discharge valve 50 or the fine discharge valve 50 and the raw discharge valve 51 are ratified. The result of these valve actions will be a reduction in air pressure in the clutch chamber 45 with a subsequent reduction in clutch torque. This reduced torque reduces the torsional load of the motor 13 so that it can accelerate.

Conversely, when the combination of the engine speed and the engine gear is greater than the weighted accelerator pedal position signal, the output of the amplifier 660 on line 662 will become negative. Again depending on the magnitude of the signal on line 662, this can cause comparators 666 or 666 and 667 to energize the fine fill valve 47. The actuation of these valves causes an increase in the air pressure in the coupling chamber 45 and, consequently, an increase in the torque capability of the coupling. This will strain the engine.

When the combination of engine speed and engine speed change rate is equal to or substantially equal to the weighted accelerator pedal position signal, the output of amplifier 666 on line 662 will be small and no valve will be energized. Thus, the response of the overall system is to adjust the clutch torque so that the motor 13 operates at or near a speed set by the weighted accelerator pedal position.

In a normal mode A start, when the driver presses the accelerator pedal 31, it increases fuel flow to the engine 13 so that it accelerates. At the same time, clutch control circuit 116 will increase clutch torque until the engine speed is kept at the speed set by the weighted accelerator pedal position signal. The resulting torque will accelerate the vehicle. During this time, clutch 12 transfers the torque in a slipping manner when the motor speed is greater than the transmission input shaft speed. As the road speed of the vehicle 35 increases, the speed of the transmission input shaft increases. Finally, the input shaft 55 and the motor 13 will rotate at the same speed. When this happens, the motor speed will increase, causing the clutch to be engaged quickly.

Mode B clutch occurs when the vehicle is moving and the engine speed at the time of the clutch is greater than the transmission input shaft speed. Usually this occurs after an upshift. 40 In this mode, the inputs are connected to amplifier 660 through multiplexer 616 connected to line 655. These are the positive speed changes of the motor speed and the positive weighted accelerator pedal position signal. As described above, the weighted sums of these signals appearing at the output of amplifier 660 will cause the actuation of one or more of the fill or drain valves depending on the direction and magnitude of the amplifier output. In this case, 45 increased clutch torque will tend to brake the motor 13. This engine delay causes a negative voltage to appear on line 614. Typically, the weighted accelerator pedal position signal on line 633 will cause the output of amplifier 660 to become negative, so that fine fill valve 47 and / or coarse fill valve 48 will be energized. The resulting increase in clutch air pressure increases clutch torque and causes increasing deceleration of engine 13. This process continues until the 50 negative signal on line 614 resulting from the engine deceleration balances the positive weighted accelerator pedal position signal on line 633.

The operation of the system is such that during a mode B clutch the engine is decelerated to a speed set by a weighted accelerator pedal position signal. The relative values of the quantities at the balanced condition, i.e., no output from the amplifier 660, 55 are set by the ratio of the resistors 618 and 634. Furthermore, the change speed of the motor speed is weighted by the gain of the amplifier-603 depending on the gear acceleration being coupled.

19 192799

During a mode B clutch, the clutch is coupled such that the engine speed is forced to decrease to a speed that depends both on the throttle position and the gear ratio. The various factors are weighted to provide proper coupling under all conditions. The torque provided by the clutch will respond through the control line and the motor transmission arrangements. Improper clutches would result in unwanted high transient torque in the control line and / or driver feed in a jerky and jerky clutch.

The variation in the gear wheel ratio is compensated for by the variation in the weight of the engine speed term on line 614 caused by the variation in the gain of the gain 603. Furthermore, with small throttle position settings, the weighted throttle position signal on line 633 will be relatively small, making a relatively small motor speed deceleration is called up. Under these conditions, the developed torque balanced will be very small. As the accelerator pedal 31 is further depressed, calling the weighted accelerator pedal position signal on line 633 increases for a greater deceleration rate change and thereby higher torque. Thus, small accelerator clutches can be made extremely smooth in all gears. When the accelerator pedal is pressed, the clutches are made faster, but with some increase in torque.

Mode C clutches occur when the vehicle is moving and the engine speed at the time of the clutch is less than the transmission input shaft speed. Normally this is a result of a downshift. In this circumstance, the torque generated by coupling the clutch 12 will accelerate the motor 13. The accelerated motor will provide a negative signal on line 611. Analogous to the case of B-clutch mode, this signal on line 611 is balanced by the weighted accelerator pedal position signal on line 633. In all other respects, C-clutch mode will be the same as B-clutch mode except that the motor 13 will be accelerating.

In both a mode B clutch and mode C clutch, the result of the clutch torque will be that the motor speed will approach the input shaft speed. When this difference is small or zero, the D coupling condition mode will occur. Under these conditions, the multiplexer 616 connects the line 685 to the amplifier 660 through the line 686. Now the input signal to the amplifier 660 is the positive supply voltage through the resistor 684. This makes the output of the amplifier 660 on line 662 a large negative signal which energize both the fine fill valve 47 and the coarse fill valve 48. The result is coupling the coupling at the greatest possible speed. Since the speed difference across the clutch is effectively zero, the quick clutch does not cause a transition control line torque.

The coupling decoupling signal (CD) on line 641 and the high pressure (HP) signal on line 643 directly affect the coupling of coupling 12 via multiplexer 616. A prohibition signal (INHIBIT) is provided by the multiple input OR gate 642 when either the clutch release (CD) or the high pressure (HP) signal is present. The inhibit signal (INHIBIT) on line 644 disconnects the input of the inverting amplifier 660 from all speed and accelerator pedal position information fed to the multiplexer 616. When only the clutch disengage (CD) signal is present, the inhibit signal (INHIBIT) is generated by the OR gate 642 as just described and a coupling error signal is provided by the coupling decoupling signal (CD) on line 641. The coupling decoupling (CD) signal 40 is fed to the positive input of an inverting amplifier 660. When the coupling decoupling (CD) signal is present, the error signal on line 662 becomes highly positive and triggers both comparators 664 and 665, which open the coarse drain valve 51 and fine drain valve 50 in their turn. When only the high pressure signal (HP) is present, the dual input OF-pood 642 provides the prohibition signal (INHIBIT) on line 644. When this prohibition signal is present, the multiplexer 45 616 connects all inputs to the invading amplifiers 660 and the coupling error signal. on line 662 becomes zero. So no fill or drain valve will be open. In this way, the pressure in the chamber 45 of the clutch operator 18 can be maintained at a constant predetermined level.

The generation of the switching point by the transmission 10 will now be described with reference to Figure 10.

50 Gear selection, motor operating conditions and power supply operation are related. The shifting circuit 115 controls gear selection in such a way that optimum operation is maintained. This optimum may vary by design to satisfy different food configurations, designs and requirements of the vendor or operator. To meet these different requirements, a number of input signals are used including the motor speed in the adjacent 55 gears; acceleration of the food; accelerator pedal position and the speed of change of the accelerator pedal position; the direction and time elapsed since the last shift and the motor speed history since the last shift.

192799 20

To facilitate understanding of these circuits, reference is made to Figure 10: a graph of static shift point profiles for the six forward gears of the transmission 11. Calculated motor speed (GOS) is plotted along the abscissa and the accelerator pedal (TP) position is plotted along the ordinate.

5 The switch point profiles consist of three parts. The first is the 35-100% range of the accelerator pedal position in which the shift points increase linearly with the accelerator pedal position. Second, there is a range of full throttle upshifts and downshifts for each gear. These are shown along the limit line above 100% accelerator pedal position. Finally, in the range of 0-35% throttle, the downshift points are fixed at the 35% throttle value, while upshifts 10 are fixed at the full throttle upshift limit.

Two voltage signals are generated in each gear, which is derived from the accelerator pedal position (TP) signal. These voltages are compared to voltage signals representing the calculated motor speed (GOS). The downshift and upshift lines are thus graphical representations of the relationship between these generated voltages and the accelerator pedal position (TP) signal, but shown in terms of their corresponding engine speed equivalent. These lines will be referred to as the accelerator-modulated shift profile.

Usually the duty point 1 will fall between the downshift profiles on the left and the upshift profiles on the right. When the motor duty point 1 will move from the left of the downshift profiles, an automatic downshift request (HD) is sent to the accelerator circuit 20 113. When according to the duty point 1 moves from the right of the upshift profiles, an automatic upshift signal (AU) is generated.

The shift initiator circuit 115 provides two such profiles for each gear.

(Note that in the cases of the first and top gear, one profile is meaningless, ie no upshifting is possible above the top gear).

The changeover profiles are typically moved equally on each side of the peaks of the fuel consumption curves, limiting operation to the most fuel efficient areas. It would be desirable from a fuel efficiency standpoint to have the shift profiles as close to the peaks as possible. However, they must be separated by at least the split between the various gear ratios of the transmission 11.

For the system shown, the gear ratio is 7.47 · 4.08; 2.36; 1.47; 1.00 and 0.776 in gear 1 to 6. As an example of the limited success achieved using only static upshift and downshift profiles, the vehicle is assumed to operate in fifth gear and accelerate slowly (paragraph 2). At 1600 rpm, an upshift to sixth gear would be requested. In sixth gear, the motor speed would be reduced by the numerical ratio of the fifth gear ratio to the sixth gear ratio, that is, 1600 * 1.00 / 0.778 or 1250 revolutions per minute. This corresponds to point 3 of Figure 10. As shown, point 3 is on the right side of the sixth gear downshift line and the upshift can be made thereby. If the changeover profiles had been closer to each other, a situation could arise in which point 3 falls to the left of the downshift profile. Should this occur, the transmission would be rushed, i.e. any upshift would result in an immediate downshift instruction which in turn would generate an upshift. Such instability or rushing is not acceptable.

In the preceding example, it was assumed that all conditions remained constant during and immediately after the switch. In reality, few of these conditions remain constant. During a switchover, the control line torque will be momentarily interrupted. Consequently, the motor speed will not remain constant. Demand for horsepower requirements can vary quickly if they occur when the vehicle suddenly has to go up a slope. Finally, the driver can change the accelerator pedal position before, during or as a result of shifting.

50 In shift initiation circuit 115, the base throttle modulated shift profiles are modified to properly account for the many dynamic conditions and to interpret the driver's intentions as indicated by throttle movement. These various modifications and their purpose will be described below.

55 To enable the throttle-modulated gear shift profiles shown in Figure 10 to be positioned as close together as possible, provision has been made to change their location depending on their recent history. To accomplish this, the accelerator circuit 113 provides signals 21 192799 which are indicative of the direction of the last shift. These signals, last upshift (LU) and last downshift (LD), are then generated when the accelerometer changes and are stored in memory.

After each upshift, the last upshift signal (LU) modifies the downshift profiles.

5 This modification has two components. A static component moves the downshift profiles from the normal position shown in Figure 10 to lower motor speeds. This set-up will typically be 100 to 150 revolutions per minute. In addition to this static shift, the downshift profiles are temporarily shifted another 100 to 150 revolutions per minute. The downshift profiles then return to the static residual shift from 100 to 150 revolutions per minute over a period of several seconds.

Likewise, the upshift profiles are moved to the right after each downshift.

As claimed, the static portion of the shift is maintained while the last upshift (LU) or last downshift signal (LD) remains. Additional circuitry is provided to reset the memory. After each upshift, a memory reset signal is generated when the motor operating point crosses the reset line RR from left to right. After a downshift, a reset signal is generated when the operating point crosses the reset line RR from right to left.

The reset line RR may move dynamically. Typically, this involves moving the reset line RR at about 300 revolutions to the left after an upshift and an equal amount to the right after a downshift.

These movements allow the throttle-modulated gear shift profiles to move closer together without causing instability. In addition, the transition portions allow the system to ignore various transition oscillations of the control line which may occur as a result of switching. The provision of a reset minimizes the possibility of operation out of the range defined by the static accelerator modulation profiles.

The static downshift and upshift profiles also ignore the effects of vehicle acceleration and deceleration. In the shift initiation circuit 115, this factor is included in the shift decision by shifting the throttle-modulated downshift and upshift profiles by an amount proportional to the vehicle acceleration and deceleration. Typically, the 30 downshift profiles offset to the left at a rate of 7.2 revolutions per minute, per mile per hour, per minute of vehicle acceleration, and to the right an equivalent amount of vehicle deceleration. The shift-up profiles are offset to the right at the rate of 16.4 revolutions per minute, per mile per hour, per minute vehicle deceleration. There is no corresponding left offset of the vehicle gear upshift profiles.

35 The effects of this movement can be illustrated by two examples.

First consider the case of vehicle operating point at point 4 of figure 10. Stable operation implies that the accelerator pedal position is set so that the power delivered by the engine corresponds to that used by the vehicle, that is to say the speed of the accelerator. vehicle is constant. Now assume that the driver then fully depresses the accelerator. The operating point will shift to point 5. 40 On a static changeover profile basis, this would result in a downshifting of the operating conditions to point 6. The engine horsepower will then be substantially above demand and the vehicle will accelerate, resulting in a requirement to shift up to the original gear.

When the vehicle gear shifts the shift profile to the left, point 5 can remain to the right of the downshift line and no downshift will occur. The surplus of horsepower 45 will still be sufficient to accelerate the vehicle and no unnecessary follow-up of changes will occur.

As a second example, it is assumed that a vehicle is operating with a fully depressed accelerator above 1600 revolutions per minute, which vehicle is to climb an incline sufficiently steep to create a downshift requirement. On a static base, the motor speed should drop from 50 to 1300 revolutions per minute before downshifting will occur. The deceleration induced movement of the shifting profile will cause the downshift to occur at a higher engine speed thereby improving the operation of the vehicle's movement.

In addition, the shift profiles can be moved in response to the speed of the accelerator pedal movement. For example, consider a vehicle operating at point 7, which has to descend a downward slope of 55 on which the driver does not wish to accelerate. Its normal response will be to return the accelerator pedal to operating point 7. At point 7, no upshifting will occur since the accelerator circuit 113 does not upshift if the accelerator is not depressed.

192799 22

On the other hand, since the operating point traverses the area between points 7 and 8, an upshift will occur. If the accelerator pedal position change speed has moved the upshift profile to the right, this problem will not occur. Accordingly, when returning from point 8 to point 7, the upshift profile will be shifted to the right again. The upshift profile is thus typically shifted to the right by the absolute value of the rate of change of the accelerator pedal position.

On their own, the accelerator-modulated shifts could result in incorrect shifts. Under no circumstances can a downshift be allowed which would result in excessive motor speed. Thus, the shift initiation circuit 115 includes a limiting downshift speed for each gear. In order for a downshift to occur in either automatic or manual mode, the calculated motor speed signal (GOS) must be less than the downshift release (DE) signal.

A limited speed for upshifts is also provided, namely the upshift limit (UL). This limitation is desirable for two reasons. First of all, in many cases the throttle-modulated shift profile, especially with large splits between gears, can lead to excessively high upshift speeds with a fully depressed throttle. Second, the various factors driving the upshift profile can move the upshifts even to even higher speeds.

In automatic mode (AUTO), an upshift will be requested when the calculated motor speed (GOS) is greater than either the modulated value (AU) or the limited value (UL).

Usually there will be a full set of set points: one for each gear. The gear shift limit values (UL) will typically be set close to the speed at which the engine driver begins to limit the power of a fully depressed accelerator. The downshift release limit signal (DE) is then set to be approximately the acceleration distance below the upper limit setting for the next lower gear. For example, in the case of the transmission with a distance of 1.28 between fifth and sixth gears, the sixth gear downshift release settings would be roughly equal to the fifth gear upper limit setting divided by 1.28.

Separation of these limiting signals UL and DE is controlled by the acceleration distance. As is the case with modulated profiles, these limit values are shifted by the last upshift and last downshift signals. As shown in Figure 10, the downshift enable signal is decreased by the last upshift signal LU, while the upshift limit speed UL is reduced by a last downshift signal (LD).

Usually, measures have also been taken to cause the limiting signals to move in response to other operating conditions. Downshift release (DE) signal is active in manual mode (MAN). In this mode, the limit is typically increased close to the maximum at which a downshift can be safely performed without increasing the no-load driver speed of the engine.

In some applications it is desirable to give the driver additional control of the switch points.

40 The downshift release signal (DE) allows downshifting in manual mode (MAN) only when the calculated motor speed (GOS) is below the set point. In manual mode (MAN), the downshift release setpoint (DE) is normally moved to the highest speed in any gear at which a downshift can be completed without increasing the maximum safe motor speed.

45 It is desirable and / or necessary to use engine compression brakes when driving down long or steep slopes. Under these conditions, the driver's foot will not be on the accelerator and downshifts would occur at low engine speeds, resulting in small engine decelerations. Accordingly, the accelerometer circuit 113 is provided with a signal (BS) when the vehicle's brakes are applied. At this time, a downshift occurs at 50 as soon as the downshift enable signal (DE) allows. At the same time, the brake signal (BS) will typically increase the downshift release setting signal to a higher than normal speed. This allows the most effective engine compression brakes to occur naturally.

For some applications it is desirable to provide a "full throttle" action similar to that provided in some passenger car transmissions. Typically, this would consist of a switch 55 with a detent actuated in the extreme position of the accelerator pedal. When the accelerator pedal is depressed to the extreme position, a throttle-on-the-plank (ftTD) signal is generated by the throttle-on-the-plank switch 35.

23 192799

In gas-on-the-shelf conditions, both the downshift release signal (DE) and the upshift limit (UL) rates will be increased. This provides additional gear selection control which is particularly advantageous on slopes. At normal upshift limit settings, upshifting will result in lower engine power availability at low engine speed. Thus, for example, on ramps, upshifts may result in insufficient power to maintain vehicle speed. This problem is further aggravated by the fact that under these conditions the vehicle speed can drop significantly during the shift.

This problem can be solved by increasing the upshift limit (UL) under gas-on-the-shelf conditions. Typically, the upshift limit (UL) setting may be moved to an area of regulator down so that there will always be increased power or torque available after upshift. Normally this entails the disadvantage of vehicle deceleration during the switchover.

Increasing the downshift release setting (DE) allows the driver to force past downshifts. This is advantageous when the operator is on a slope where downshifting will be required. The earlier downshifting will result in a minimal decrease in vehicle speed. The off-the-shelf feature can also be used to provide additional gear for situations such as passing another vehicle.

As was the case with the throttle-modulated shift profiles, location and movement of the limiting shift points can be adjusted to satisfy other needs. For example, to improve the fuel economy, the upshift limit (UL) for the 20 next top gears can be set slightly lower than for the other gears and cannot be moved further by the RTD or last downshifts (LD). The result limits the maximum engine speed when the motor vehicle is operating at higher road speeds.

Other changes of the switch points may be desirable for special circumstances. It has been observed that in some vehicle configurations a much flatter ride can be obtained when upshifts do not occur when the vehicle accelerates rapidly. This can be accomplished by forbidding upshifts while the output axis change rate exceeds preset levels.

It has also proven advantageous to achieve a minimum calculated motor speed below which a downshift is commanded. This can be achieved in part by appropriately shaping the throttle-modulated shift point characteristic. Movement of this profile through vehicle acceleration and other factors can lead to situations where an engine stalling condition has been approached. To avoid this possibility, a speed signal that is too low is generated when the calculated motor speed (GOS) falls below a preset level. This overspeed signal forces a downshift request (AD).

35

Signal Glossary:

The following glossary includes analog and digital signals provided to, operating on or generated by the central processing unit 24 of the mechanical automatic transmission 10. This glossary includes a brief description of each signal and, in the case of digital signals, a further explanation 40 regarding to the state of the signal (high or low) when the given condition is true or false. The glossary will be useful when used in conjunction with the signal generation and function list of Figure 4.

SIGNAL GLOSSARY

45 -; -; -

Logic signal Abbreviations Description

Alarm ALARM signal generated by the accelerometer circuit 113 operating on an audible 50 alarm 27 to warn the driver of an incorrect action. When ALARM = 1, the audible alarm is on.

192799 24 SIGNAL GLOSSARY {continued)

Logic signal Abbreviations Description (continued) 5 Automatic downshift AD downshift request generated by the shift initiate circuit 115 based on throttle modulated speed profile. AD = 1 when switching is requested.

10 Automatic AUTO signal from driver shift control 26 indicating that the driver has selected the automatic mode. When AUTO = 1, switches are initiated automatically based on the logic rule and / or requests 15 by the switch initiator circuit 115.

Auto Upshift AU upshift request generated by the upshift initiator circuit 115 based on the throttle modulated speed profile. AU = 1 when switch 20 is requested.

Brake on BS signal obtained from the brake switch 38 on the vehicle. This is used to change the downshift speeds in automatic mode. BS = 1 when the brakes 25 are on.

Calculated motor speed GOS is a DC analog signal equal to the speed of the output shaft scaled by the numerical value of the ratio.

Clock Clear CLE clears the counter, used to generate acceleration codes, to respond to clock pulse. This signal is generated by use in the accelerator circuits.

Clock pulse CP signal generated by the clock pulse oscillator when the count clearing signal is true.

Under these conditions, the clock pulse oscillator will provide clock pulses at a fixed rate, typically at 100 pulses per second.

Clutch release CD signal used to instruct clutch release. This signal energizes the discharge valve 40 52 associated with the coupling 12.

Coupling coupling MODE A, coupling coupling modes. These logic MODE B signals are generated by the coupling MODE C, control circuit 116 and are used for the MODE D switching of various analog inputs 45 to the coupling error amplifier.

Coupling prohibition INHIBIT logic signal generated by the coupling control circuit 116 which blocks the normal analog inputs to the coupling error amplifier.

50 Downshift Release DE signal generated by the shift initiate circuit 115 when the output shaft speed is low enough to allow a downshift to the next lower gear without resulting in excessive motor speed. The de-signaa! used in both automatic and manual modes.

25 192799 SIGNAL GLOSSARY (continued)

Logic signal Abbreviations Description (continued) 5 Downshift DN impedance signal in accelerator circuit 113 which represents the conditions in which a countdown will be made. This has been defined as an aid in determining the conditions necessary for a count clearing signal to be generated.

Too high motor speed EH signal derived from the speed and synchronization circuit 112 from a comparison of the calculated motor speed (GOS) and the actual motor speed (ES). EH = 1 when the actual motor speed is greater than the calculated motor speed.

Motor speed too low EL signal derived in the speed and synchronization circuit 112 from a comparison between the calculated motor speed (GOS) and the actual motor speed (ES). EL = 1 when the actual motor speed is less than the calculated motor speed.

Motor speed ES is a direct current analog signal proportional to the speed of a motor 13.

Error E signal generating speed and synchronization circuit 112, which is based on a comparison of the output speed divided by the gear ratio for the selected gear. When the absolute value of the 30 signal exceeds predetermined limits, E = 1.

Error condition HOLD signal generated by logic to indicate an actual or potential error condition.

No holding circuits are provided.

Typical conditions for generating a hold signal could be loss of truck pressure, low battery voltage, speed pick-up failure, and so on.

Fuel valve FV signal used to control the flow

40 from the fuel to the engine 13. When FV

= 1 fuel is supplied.

Accelerator GCN this refers to the four-bit code developed by the accelerometer circuit 113 to specify the selected gear.

45 Gear set old JRC this refers to the four-bit code on the output of the lock 401 in the instruction logic circuit 114 which maintains the existing binary code gear information until a physical switch to a new 50 gear is acceptable.

Gear selection control M1, M2, M3, signals used to control the M4, M5, M6, solenoid valves 69 which accomplish gear selection MN, NR, O. When M (N) is true, the valves will physically place the transmission in (N) 55 gear. The value of M (1, 2, 3, 4, 5, 6, N or R) is specified by GCN.

192799 26 SIGNAL GLOSSARY (continued)

Logic signal Abbreviations Description (continued) 5 High pressure HP signal generated by the pressure switch 54 which senses the coupling air pressure. The switch 54 operates when the clutch air pressure exceeds the circuit count. HP = 1 when the clutch is coupled in the 10 set point.

Ignition IGN signal derived from the vehicle ignition switch 25 indicating that the ignition switch is on when IGN = 1.

Low pressure LP signal generated by the pressure switch 53 which senses the clutch air pressure. An LP = 1 signal indicates that the clutch air pressure is below the clutch threshold. LP = 1 when the clutch is disengaged.

MAN manual shift signal from the control shift control 26 indicating that the selector lever is in the manual position. MAN = 1 when the selector switch is in the manual position.

Manual downshift MDM shift signal from the control shift control 26 indicating that the selector switch lever is in the manual downshift request position.

Manual upshift MUP shift signal from the control shift control 26 indicating that the selector lever is in the manual upshift request position.

30 NEUTRAL neutral signal from control shift control 26 indicating that the selector lever is in the neutral position.

A ONE signal generated by the accelerometer circuit 113 to ensure that the accelerometer will change only one beat each time the selector switch is moved from the MUP or MDN position.

Output axis speed OS is a DC analog signal proportional to the speed of the output axis 14.

40 Overspeed O signal generated in the speed and synchronization link 112 indicating that the motor 13 could start running at too high a speed if a shift was completed in the selected gear. This signal is based on a comparison between the calculated motor speed {GOS) with a fixed reference.

Reset RESET signal generated by the accelerometer circuit 113 and used to reset the accelerometer to the "0" state 50 (neutral selection). The reset signal prefers all other signals and independently forces the accelerometer to the "0" position. of all other signals.

Reverse REV signal from driver changeover controller 55 26 indicating that the selector lever is in reverse.

27 192799 SIGNAL GLOSSARY (continued)

Logic signal Abbreviations Description (cont.) 5 Throttle on the plank switch RTD lock switch 35 physically associated with the accelerator pedal 31. The switch 35 operates with a strong detent action when the accelerator pedal is pressed down to the limit. RTD = 1 at greater than full throttle travel.

10 Select first gear, S1, S2, S3, shortcut notation for gear selection specified and so on. S4, S5, S6, in accelerometer binary code. S1 means SR, SN that the binary code counter corresponds to the first gear, and so on. SR means that the accelerometer binary code indicates a neutral choice. SN means that the accelerometer binary code indicates a reverse gear selection.

Downshift SDN signal generated and used by the accelerometer circuit 113 when a downshift is requested by one of the possible sources.

Upshift SUP signal generated by and used by the accelerator circuit 113 when a circuit has been requested from one of the 25 possible sources.

Synchronization enable SE a signal generated by the instruction logic circuit 114 when three conditions exist for operation of the synchronizer clutch or brake. When SE = 1, synchronization 30 can take place.

Accelerator pedal position TP is an analog resistance signal proportional to the accelerator pedal position 31.

Throttle switch TS signal generated by the switch 34 associated with the accelerator pedal 31. This switch energizes with light pressure on the pedal 31 and is used to indicate logic that the driver's foot is on the accelerator. TS = 1 when the foot is on the pedal.

40 Transmission neutral GN signal derived from the neutral switch 73 on the transmission 11 operating when a changeover rail is moved from the neutral position. GN = 1 when the transmission is mechanically in neutral. (Note: GN = 0 45 does not mean that the transmission is actually in gear).

Low vehicle speed U signal generated by the speed and synchronization circuit 102 when the speed of the output shaft 15 falls below a 50 predetermined set point, typically 60 to 70 revolutions per minute. U = 1 when the output shaft speed is less than about 70 revolutions per minute.

192799 28 SIGNAL GLOSSARY {continued)

Logic signal Abbreviations Description (continued) 5 Shift UP signal generated by the accelerometer circuit 113 and used to control the accelerometer when an addition is to be made.

Upshift limit UL signal generated by the shift initiation circuit 115 indicating that the motor speed exceeds a variable limit. This signal is generated by comparing the calculated motor speed (GOS) with the limitation.

15 ------ LOGICAL RULES Accelerator Circuit (113) UP MUP. ONE .U.S6. HOLD + AUTO. TS. You. S6. HOLD + 20 MUP. ONE. TS. SN. You. HOLD +

CAR . TS. S0. You. HOLD

DN MDN. ONE. SI. SN. SDN. HOLD + AUTO. TS. SDN. SI. S0. HOLD + 25 AUTO. SDN. (S4 + S5 + S6). HOLD + AUTO. You. (S4 + S5 + S6). HOLD +

U3. S1. SN. HOLD

Clock release = UP + DN

30 Reset REV. You. IGN. HÖLD + C03.U + GN.U. HOLD + IGN. U + AUTO. MUP. SN. U + 35 NEUT. U + C03 REV. TS. You. IGN. HOLD + C03.U + REV. C03. IGN 40

Alarm REV. CÖ3 + MDN.ONE.SDN + IGN. You JMEUJ. GN + NEUT. You. GN 45 SND DE. Ö. (AD + AÜTÖ + BRAKE + RTD)

SUP AU - RTD + UL

50 Instruction logic circuit (114)

S sets: (GCN * GCO) + E

reset: E. SE

M (N) JRC (N). S

55 SE = S. GN. LP

Claims (2)

29 192799 CD = S + (Ë. SE) d. Ü + U. TS FU = FUL. IGN TD puts: S. You. EH_ reset: U + EH 5 ____________ 10 Electronic steering system for an automatic transmission mechanism of a vehicle, to which, by various sensors as input signals and operating parameters: the gear to which has just been switched; the throttle angle set via the accelerator pedal; the engine speed; and the vehicle speed are supplied, wherein the electronic steering device is provided with a memory device and logically processes these input signals and generates output signals for driving a transmission mechanism actuator by means of stored characteristic switching lines, with means for changing the stored characteristic shift lines by modifying at least one of the operating parameters, characterized in that the modifying means is adapted to change the engine speed, with upshifts and downshifts being commanded, in response to the input signal representative of the engine speed by modifying the stored characteristic shift lines for a predetermined time interval following the selection of a new gear ratio. Hereby 13 sheets drawing