JP2852518B2 - How to determine shift lever position signal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a method for determining a shift lever position signal of a control system that changes control according to a shift lever position in a vehicle having a continuously variable transmission, an automatic transmission, an automatic clutch, and the like. The present invention relates to a determination method when a lever position signal is input.

[Prior art]

In a transmission that automatically shifts, shift lever positions such as parking (P), reverse (R), neutral (N), drive (D), and sporty drive (Ds) are generally set. , The lever position is electrically detected by a sensor such as an inhibitor switch, and various controls are performed to switch the transmission to neutral, forward and backward running, change of a shift pattern, and the like based on the lever position signal. Also in the automatic clutch, the clutch disconnection and other various controls are performed by the lever position signal. For this reason, the lever position signal is important as an input signal for the control system. However, a plurality of signals may be erroneously input due to a sensor failure, a break in a harness, a short circuit, or the like. There is a need. Therefore, conventionally, regarding the determination of the lever position signal,
For example, Japanese Unexamined Utility Model Publication No. 60-155461 discloses a prior art, which discloses that when a reverse signal is output and the vehicle speed is other than substantially zero, the reverse signal is invalidated.

[Problems to be solved by the invention]

However, in the above-mentioned prior art, only the determination of the reverse signal is performed only, and no measures are taken for other shift lever positions, which is insufficient. In general, when a plurality of signals are input, it is conceivable to determine a failure and activate a fail-safe program for ensuring traveling. However, there is a drawback that the number of signals for the lever position is large and this signal is used in a large number of points in the program, so that the number of fail-safe programs is very large. The present invention has been made in view of such a problem, and when a plurality of shift lever position signals are input, a fail-safe is unnecessary by always making an optimal determination in relation to a vehicle state. It is an object of the present invention to provide a method for determining a shift lever position signal.

[Means for Solving the Problems]

In order to achieve the above object, a method for determining a shift lever position signal according to the present invention determines a vehicle state from a vehicle speed signal and an engine load signal, sets a priority of the shift lever position in advance from the vehicle state, and sets a shift lever position. A shift position determination unit determines a signal from a sensor that electrically detects a position based on the priority, selects one lever position,
A lever position signal corresponding to the lever position is output. It is preferable that the vehicle stop mode and the traveling mode are determined as the state of the vehicle. In the vehicle stop mode, the stop position is prioritized over the traveling position, and in the traveling mode, the traveling position is prioritized over the stop position. In the vehicle stop mode, the vehicle is divided into a stop mode in which there is no intention to start and a start mode, and in the start mode, the traveling position may be determined in a priority order almost in the same manner as when traveling. In driving mode, it is divided into low speed region and high speed region mode,
In the high-speed range mode, the priority of the R position may be set to the lowest. In addition, the plurality of traveling positions in each mode may be determined such that the higher the gear ratio, the higher the priority.

[Action]

According to the above-described determination method, the electric lever position signal from the shift lever position sensor side is input to the determination unit to determine the lever position. When a plurality of lever position signals are input, the signal of the position with the highest priority is output. Selected and output. The stop position is preferentially selected under the condition of stopping the vehicle. In this case, the running position is preferentially selected under the start condition, and the start is ensured. Under the traveling conditions, the traveling position is preferentially selected and traveling continues. In this case, the degree of selection of the backward movement of the R position in the high-speed region is very small, thereby ensuring safety. At the traveling position, a gear having a large gear ratio is preferentially selected, so that traveling is always ensured.

【Example】

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Referring to FIG. 1, an overall configuration of a drive system in which an electromagnetic clutch is combined with a belt-type continuously variable transmission as a vehicle to which the present invention is applied will be described. The engine 1 is provided with a continuously variable transmission 4 via an electromagnetic clutch 2 of electromagnetic powder type or the like and a forward / reverse switching device 3.
And a set of reduction gears 5 from the continuously variable transmission 4
It is configured to transmit power to drive wheels 9 via an output shaft 6, a differential gear 7, and an axle 8. The electromagnetic powder type clutch 2 has a drive member 2a on an engine crankshaft 10 and a driven member 2b having a clutch coil 2c on an input shaft 11. And clutch coil 2c
The electromagnetic powder is coupled and accumulated in the gap between the two members 2a and 2b in a chain by the clutch current flowing through the clutch, and the clutch engagement / disengagement and clutch torque are variably controlled by the coupling force. The forward / reverse switching device 3 is synchronously meshed with a gear, a hub, and a sleeve between the input shaft 11 and the transmission main shaft 12, and includes a forward position at which the input shaft 11 is directly connected to the main shaft 12, and an input shaft. And a retracted position for transmitting the rotation of the rotation 11 to the main shaft 12 in the reverse direction. The continuously variable transmission 4 includes a main shaft 12 and a sub shaft arranged in parallel with the main shaft 12.
The primary shaft 12 is provided with a primary pulley 14 having a hydraulic cylinder 14a having a hydraulic cylinder 14a and the secondary shaft 13 is similarly provided with a secondary pulley 15 having a hydraulic cylinder 15a. A drive belt 16 is wound around both pulleys 14 and 15, and both cylinders 14a and 15a are configured as a hydraulic control circuit 17. Then, a line pressure according to the transmission torque is supplied to both cylinders 14a and 15a to apply a pulley pressing force, and the primary pressure changes the ratio of the winding diameter of the drive belt 16 to the pulleys 14 and 15 to continuously change the speed. It is configured to control. Next, an electronic control system of the electromagnetic powder type clutch 2 and the continuously variable transmission 4 will be described. Engine speed sensor 19 for engine 1 and primary pulley speed sensor 2 for continuously variable transmission 4
1, a secondary pulley rotation speed sensor 22, and sensors 23 and 24 for detecting the operation status of the air conditioner and the choke. Also,
The shift lever 25 of the operation system is mechanically coupled to the forward / reverse switching device 3 and has a shift lever position sensor 26 for detecting each of the ranges P, R, N, D, and Ds. In addition, the accelerator pedal
27 is an accelerator switch that detects the accelerator depressed state
And a throttle opening sensor 29 on the throttle valve side. The various signals of the switches and the sensors are input to the electronic control unit 20 and processed by software using a microcomputer or the like. The clutch control signal output from the electronic control unit 20 is input to the electromagnetic clutch 2 and the shift control signal and the line pressure control signal are input to the hydraulic control circuit 17 of the continuously variable transmission 4 to perform each control operation. I have. 2, the electromagnetic clutch control system and the continuously variable transmission control system of the control unit 20 will be described. First, in the electromagnetic clutch control system, the engine speed Ne and the shift position determination unit 60 (shift lever position sensor 2
6) has a reverse excitation mode determination unit 32 to which a signal in the P, N range other than R, D, and Ds is input, for example, when Ne <300 rpm, or
In the P and N ranges, the mode is determined to be the reverse excitation mode, and the output
3 allows a small current to flow in the opposite direction to normal. Then, the electromagnetic clutch 2 is completely released except for the residual magnetism. Also,
It has an energization mode determination unit 34 to which a determination output signal of the reverse excitation mode determination unit 32, a depression signal of the accelerator switch 28, and a rotation (hereinafter referred to as vehicle speed V) signal of the secondary pulley rotation speed sensor 22 are input. The running state is determined, and this determination signal is input to the start mode current setting unit 35, the drag mode current setting unit 36, and the direct connection mode current setting unit 37. The start mode current setting unit 35 sets the start characteristics individually in relation to the engine speed Ne and the like in the case of normal start or start using the air conditioner and choke. Then, the starting characteristics are corrected based on the travel ranges of the throttle opening θ and the vehicle speeds V, R, D, and Ds, and the clutch current is set. The drag mode current setting unit 36 determines a small drag current when the accelerator is released at a low vehicle speed in each range of R, D, and Ds,
A drag torque is generated in the electromagnetic clutch 2 to reduce the play of the belt and the drive system, thereby smoothly starting the vehicle. In this mode, the current is determined to be zero current until just before the vehicle stops after the clutch in the D range is released, thereby ensuring the coasting. The direct-coupling mode current setting unit 37 determines the direct-coupling current based on the relationship between the vehicle speed V and the throttle opening θ in each of the ranges of R, D, and Ds, fully engages the electromagnetic clutch 2, and saves power in the engaged state. . The output signals of these current setting units 35, 36, and 37 are input to the output determination unit 33, and the clutch current is determined according to the instruction. Next, the shift speed control system of the stepless speed change control will be described. , The actual speed ratio i is calculated from the actual speed ratio i = Np / Ns. The actual gear ratio i and the throttle opening θ of the throttle opening sensor 29
Is input to the target primary pulley rotation speed search unit 41, and R, D,
A target primary pulley rotation speed NPD is searched for each range of Ds using a map of i-θ based on a shift pattern.
The target primary pulley rotation speed NPD and the secondary pulley rotation speed Ns are input to the target gear ratio calculator 42, and the target gear ratio is
It is calculated by is = NPD / Ns. And this target gear ratio i
s is input to the target gear ratio change speed calculation unit 43, and the target gear ratio change speed dis / dt is calculated based on the change amount of the target gear ratio is for a certain time
Is calculated. And these actual gear ratio i, target gear ratio is,
The target speed ratio change speed dis / dt and the coefficients K ₁ and K of the coefficient setting unit 44
₂ is input to the shift speed calculating unit 45, and the shift speed di / dt is calculated as follows. di / dt = K ₁ (is−i) + K ₂ · dis / dt In the above equation, is−i is a control amount of the target and actual speed ratio deviation, and dis / dt is a delay correction element of the control system. The gear speed di / dt and the actual gear ratio i are the duty ratio search units.
Enter 46. Here, the duty ratio D of the manipulated variable is D
= F (di / dt, i), the duty ratio D becomes di / dt in upshift and downshift.
-Searched using the map of i. The value of the duty ratio D of the manipulated variable is supplied to the hydraulic control circuit
Output to the 17 speed change control solenoid valve 48. Subsequently, a line pressure control system of the continuously variable transmission control will be described. Engine speed sensor 19, throttle opening sensor 29
And an engine torque search unit 50 to which the engine speed Ne and the throttle opening θ are inputted, and obtains the engine torque T from the torque characteristic map of θ-Ne. This engine torque T
The signal of the actual gear ratio i of the actual gear ratio calculator 40 is input to the target line pressure setting unit 51, and the target line pressure PLd is determined by the product of the required line pressure corresponding to the engine torque and the actual gear ratio i. On the other hand, since the maximum value of the line pressure fluctuates as the pump discharge pressure changes depending on the engine speed, the maximum line pressure search unit 52 for inputting the engine speed Ne and the actual speed ratio i to detect this fluctuation state. And the maximum line pressure PLmax is obtained from the Ne-i map. The target line pressure PLd and the maximum line pressure PLmax are input to the pressure reduction value calculation unit 53, and the line pressure P is calculated as a ratio of the target line pressure PLd to the maximum line pressure PLmax.
LR is calculated, and this is input to the duty ratio search unit 54 to determine the duty ratio D according to the line pressure PLR. The duty signal is output to the line pressure control solenoid valve 56 via the drive unit 55. Therefore, the control system has a shift position determination unit 60 on the output side of the shift lever position sensor 26 as determination control of the shift lever position signal, and the shift position determination unit 60 has a throttle opening for determining the state of the vehicle. The signal of the secondary pulley rotation speed Ns according to θ and the vehicle speed is input. Also, it has a priority order setting unit 61 for setting a priority order according to the state of the vehicle, and when a plurality of sensor signals are input, the shift position determination unit 60 sets the shift lever position according to the priority order of the priority order setting unit 61. The selected position signal is output to the reverse excitation mode determination unit 32 of the clutch control system and the target primary pulley rotation speed search unit 41 of the continuously variable transmission control system. Priority setting unit 61 has a stop mode without vehicle stop mode is willing throttle valve set opening theta ₁ following the start as shown in the table of FIG. 3, the Surotoru valve set opening theta ₁ or launch mode of Is set. The running mode and the low-speed range mode rotational speed Ns ₁ following the secondary pulley set is set to the secondary pulley set rotational speed Ns ₁ or more high-speed range mode. And in the stop mode,
As shown in the figure, the order is determined by giving priority to the stop positions of N and P. In the start mode, the order is determined by giving priority to the travel positions of R, Ds, and D. Since the P range is not possible in the running mode, the P range is ignored, except that the running position is prioritized in the low speed range mode, and the R range is set to the lowest rank in the high speed range mode. Here, at the traveling positions of R, Ds, and D, the priority order is R>Ds> D based on the magnitude of the gear ratio. Incidentally, for the above-mentioned throttle valve set opening theta ₁ and the secondary pulley set rotational speed Ns _1, it is preferable to provide a hysteresis to decrease side with increasing side. Next, the operation of the electromagnetic clutch 2 in the vehicle configured as described above will be described. First, in the P and N ranges, a negative current flows through the electromagnetic clutch 2 by the reverse excitation mode determination unit 32, and the electromagnetic clutch 2 is released in the state of reverse excitation. When the vehicle is shifted to any one of the ranges R, D, and Ds, and the vehicle is in a substantially stopped state with the accelerator released, a slight drag torque is generated in the electromagnetic clutch 2 by the drag mode current setting unit 36 to generate creep, When the accelerator pedal is depressed, the mode is switched to the start mode current setting section 35, and a clutch current corresponding to the engine speed flows to smoothly engage the electromagnetic clutch 2. When the set vehicle speed is reached, a direct connection current flows through the direct connection mode current setting section 37, and the electromagnetic clutch 2 is held in the engaged state. Next, the operation of the continuously variable transmission will be described. First, the power corresponding to the depression of the accelerator from the engine 1 is input to the primary pulley 14 of the continuously variable transmission 4 via the electromagnetic clutch 2 and the forward / reverse switching device 3, and the drive belt 16,
The power is shifted by the secondary pulley 15 and is transmitted to the drive wheels 9 to travel. During the traveling, the target line pressure is set to be larger as the engine torque T is larger in a low speed stage where the value of the actual speed ratio i is larger, and a corresponding duty signal is input to the solenoid valve 56 to generate a control pressure. The line pressure PL is increased by controlling the line pressure with the averaged pressure. Then, as the gear ratio i becomes smaller and the engine torque T becomes smaller as the gear shifts to the higher gear, the line pressure PL is controlled so as to decrease in the same manner, so that the transmission by the drive belt 16 is always performed. A pulley pressing force corresponding to the torque acts. The line pressure PL is always supplied to the secondary cylinder 15a, and the transmission speed is controlled by supplying and discharging oil to and from the primary cylinder 14a by a transmission speed control valve (not shown) by the control pressure of the solenoid valve 48. Will be described below. First, the signals Np, Ns, and θ from the primary pulley rotation speed sensor 21, the secondary pulley rotation speed sensor 22, and the throttle opening sensor 29 are read, and the actual speed ratio i is calculated by the actual speed ratio calculation unit 40 of the electronic control unit 20. Ask. Further, the target primary pulley rotation speed search unit 41 once searches the target primary pulley rotation speed NPD from the map based on the actual speed ratio i and the throttle opening θ, and the target speed ratio calculation unit 42 corresponds to the target primary pulley rotation speed NPD. The calculated target gear ratio is is calculated. Therefore, in the region where the primary pulley rotation speed is constant, the target speed ratio is has the same fixed value as calculated by the Ns-θ method, but in the region where the primary pulley rotation speed is variable, the target speed ratio is Ns−. As compared with the value calculated by the θ method, it is set to be offset toward the lower gear, and the target speed ratio is a value that changes by itself. Using the actual gear ratio i, the target gear ratio is, the dis / dt of the target gear ratio change speed calculator 43, and the coefficients K ₁ and K ₂ of the coefficient setting unit 44, the gear speed calculator 45 uses the gear speed di / dt. Ask for. Then, the duty ratio search unit 46 searches the duty ratio D based on the shift speed di / dt and the actual speed ratio i. The duty signal is input to a solenoid valve 48 to generate a pulse-like control pressure, whereby the shift speed control valve is repeatedly operated at two positions of oil supply and oil discharge. Here, when the duty ratio becomes small, the operation time at the refueling position becomes longer due to the off time, and the primary cylinder
Refueling at 14a, thus upshifting. On the other hand, when the duty ratio increases, the operating time at the oil discharge position becomes longer due to the on-time, and the primary cylinder 14a is drained, thereby causing a downshift.
Since the shift speed di / dt in this case corresponds to a change in the duty ratio, when the deviation between the target speed ratio is and the actual speed ratio i is small, the change in the duty ratio is small and the flow rate change of the primary cylinder 14a is small. The gear speed is slowed down due to the small number of gears. On the other hand, as the deviation between the target speed ratio is and the actual speed ratio i increases, the change in the duty ratio causes the flow rate change of the primary cylinder 14a to increase, and the speed change speed increases. In this way, in the entire shift range of the low-speed gear and the high-speed gear, the upshift or downshift is performed while changing the shift speed, and the gear is continuously changed. Further, the operation of the shift lever position determination control system will be described with reference to the flowchart of FIG. First, the operation of the shift lever by the driver is detected by the shift lever position sensor 26, and an electric signal corresponding to the operation is input to the shift position determination unit 60. The shift position determination unit 60 receives the throttle valve opening θ and the secondary pulley rotation speed Ns to determine the vehicle stop, start, low-speed or high-speed traveling states. The determination is made with reference to the priority order map shown in FIG. Therefore, when the shift lever position sensor 26 and the harness are normal and only one shift lever position signal is input, the position signal is selected and output by the shift position determination unit 60. That is, in the stop and start modes, the priority map has all the ranges including P, and has all the ranges except the P range which cannot be in the traveling mode. For example, when the D range signal is input alone. The D range is selected as it is, whereby the normal clutch control and the continuously variable transmission control according to the shift lever position are performed. On the other hand, when a plurality of lever position signals are erroneously input due to a failure of the shift lever position sensor 26, a short circuit of the harness, or the like, the shift position determining unit 60 selects the higher priority based on the priority map. So when stopping,
In that mode, the N or P priority is high, so that even if the D range signal is erroneously input, the N or P range is selected, whereby the electromagnetic clutch 2 is disengaged, and the continuously variable transmission 4 has the maximum gear ratio. Return to and secure the stop condition. When the vehicle is shifted to the travel range and the accelerator is depressed, the traveling range is selected and the electromagnetic clutch 2 is engaged, and the continuously variable transmission is controlled. It becomes possible to start. In this case,
Since the priority of the traveling range is R>Ds> D according to the gear ratio, the vehicle always starts with a large gear ratio. In the case of a low-speed range during traveling, it is determined substantially in the same manner as at the time of starting, and traveling is always ensured by selecting a range with a large gear ratio. In the high speed range, the priority of the R range is the lowest in this mode, so that the danger of suddenly moving backward with a large gear ratio is avoided. Also in this case, Ds
By giving priority to the Ds range with a large gear ratio in> D, reliable traveling is ensured. Furthermore, if the R range having the highest priority is selected and the vehicle travels backward when the vehicle travels in the above-described starting and low speed regions, the vehicle enters the high speed region mode and switches to the Ds range to move forward. High-speed running in forward running and engine braking are possible, ensuring safe running. While the embodiment of the present invention has been described above, the present invention can be applied to an automatic transmission, an automatic clutch having a different structure, and the like.

【The invention's effect】

As described above, according to the present invention, the state of the vehicle is determined from the vehicle speed signal and the engine load signal, and the signal of the sensor that electrically detects the shift lever position is determined in priority order. Fail safe for input becomes unnecessary. Since the priority order is suitable according to the state of the vehicle, a signal suitable for ensuring the state of the vehicle can always be selected in response to the input of a plurality of lever position signals in each state of the vehicle. In the vehicle stop state, the stop and the start can be secured by the priority of each mode of the stop and the start. In the running state, running performance and safety can be secured by the priority of each mode in the low speed range and the high speed range, and sufficient power performance can be obtained especially in the high speed range. Priorities for running are set according to the gear ratio,
The driving reliability is the highest.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a control system of a continuously variable transmission as an application example of a shift lever position signal of the present invention, FIG. 2 is a block diagram showing an embodiment of a determination method of the present invention, and FIG. FIG. 4 is a flowchart showing the determination operation under each driving condition. 20: Electronic control unit, 22: Secondary pulley rotation speed sensor, 26: Shift lever position sensor, 29: Throttle opening sensor, 60: Shift position determination unit, 61: Priority setting unit

Claims (5)

(57) [Claims] A vehicle state is determined from a vehicle speed signal and an engine load signal, a priority order of a shift lever position is set in advance based on the vehicle state, and a signal from a sensor for electrically detecting the shift lever position is transmitted to a shift position. A method for determining a shift lever position signal, wherein a determination unit determines one of the lever positions based on the priority order and outputs a lever position signal according to the lever position. 2. A vehicle stop and running mode is determined as the state of the vehicle. In the vehicle stop mode, the stop position is prioritized over the traveling position, and in the traveling mode, the traveling position is prioritized over the stop position. The method according to claim 1, wherein the shift lever position signal is determined. 3. The vehicle stop mode is divided into a stop mode in which there is no intention to start and a start mode, and in the start mode, the running position is determined in the same priority as in running. The method of determining the shift lever position signal. 4. The method according to claim 2, wherein the driving mode is divided into a low-speed region and a high-speed region, and the priority of the reverse position is determined to be the lowest in the high-speed region mode. . 5. The method according to claim 2, wherein the plurality of traveling positions in each mode are determined such that the higher the gear ratio, the higher the priority order.