WO1991001227A1

WO1991001227A1 - Vehicle control device

Info

Publication number: WO1991001227A1
Application number: PCT/JP1990/000916
Authority: WO
Inventors: Hisashi Kinoshita; Akira Ikuma; Hiroshi Ishikawa; Toshio Aburaya; Masaki Kawanishi
Original assignee: Nippondenso Co., Ltd.
Priority date: 1989-07-17
Filing date: 1990-07-16
Publication date: 1991-02-07

Abstract

A vehicle control device, which is provided with an acceleration detecting sensor to detect the amount of acceleration acting on the vehicle and, after removal of a low frequency component of acceleration signals output from the acceleration sensor, to exercise control over objects to be controlled on the vehicle with the use of the acceleration signals, reduces an influence of acceleration signals upon control when a state that acceleration is acting on the vehicle at a fixed rate changes to another state that said acceleration vanishes, that is, a state that the vehicle is in halt while tilting changes to that the vehicle is ready to start or a state that the vehicle is turning in normal way changes to that the vehicle runs straight. In this way, when errors occur in the acceleration signals after removal of the low frequency component with the change of the state of the vehicle, influence of the acceleration signals upon control over the vehicle can be reduced with said change of the state detected. Thus, control over the vehicle caused by erroneous acceleration signal can be prevented, thereby control satisfactory in practice being possible.

Description

Description 技術 Technical Field of Vehicle Control Equipment

The present invention relates to a vehicle control device that controls an object to be controlled of a vehicle, such as a suspension device, a brake device, and a steering device, using an acceleration detected by an acceleration sensor. Background art

2. Description of the Related Art Suspensions that actively suppress a change in the attitude of a vehicle using, for example, hydraulic pressure have been known. In the suspension, the acceleration sensor detects the acceleration acting on the vehicle, thereby predicting a change in the posture of the vehicle, and controlling the predicted change in the posture.

Conventionally, this acceleration sensor forms a vibrating piece made of a single-crystal silicon from a semiconductor substrate made of a single crystal such as silicon, for example, and responds to the magnitude of the acceleration applied by the vibrating piece. It is configured to bend. A piezoresistive element is attached to the vibrating reed, and an electric signal corresponding to the degree of bending of the vibrating reed is detected from the piezoresistive element.

However, in such a conventional acceleration sensor, the resistance value of the piezoresistive element changes with time and changes in temperature when used in severe environmental conditions for a long period of time, for example, when mounted on a car. Etc., which may result in drifts that cannot be ignored. For this reason, the conventional acceleration sensor removes the low-frequency component of the signal output from the piezoresistive element by using an AC power bleeding circuit with a capacitor, etc., and removes the acceleration that acts on the vehicle without being affected by drift. Changes can be detected. FIG. 6 shows an example of the configuration of an acceleration detection device using an AC power ringing circuit. In FIG. 6, a bridge circuit is formed by the piezoresistive elements S 1 and S 2 and the resistors R 1 and R 2, and the output signal of the bridge circuit is input to the operational amplifier A 1. After this input signal is amplified by the operational amplifier A1, the low frequency component is removed by the AC power coupling circuit composed of the capacitor C and the resistor R. The signal from which the low-frequency component has been removed is amplified by the amplifier A 2 and output as an acceleration signal.

However, according to the acceleration detecting device configured as described above, the effect of the drift can be reduced by removing the low frequency component by the AC coupling circuit, but on the other hand, the acceleration Only the change of can be detected. That is, the frequency cut off by the AC coupling circuit is determined by the values of the capacitor C and the resistor R that constitute the AC coupling circuit, and the larger the value of the capacitor C or the value of the resistor R, the greater the value. However, the cut-off frequency decreases. However, it is impossible to increase the values of the capacitor and the resistor indefinitely, and the shielding frequency of the AC power coupling circuit is usually limited to about 0.1 to 0.05 Hz. . In addition, the drift caused by the temperature change fluctuates considerably.If the cutoff frequency is set too low, the drift caused by the temperature change cannot be removed. . For this reason, the frequency cut off by the AC coupling circuit is set to a frequency that can remove the drift due to the temperature change within the above-mentioned limit range. Therefore, as shown in FIG. 7, for example, when a substantially constant acceleration acts on the vehicle for a long time, the detected acceleration gradually approaches the zero level, and the value eventually becomes zero. Then, when the vehicle returns from the state where the substantially constant acceleration is acting as described above to the state where the acceleration disappears, the acceleration in the opposite direction to the acceleration that was acting up to that time is changed. The acceleration signal from the acceleration detector Is output.

The present invention has been made in view of the above points, and reduces the influence of an acceleration signal on vehicle control when an acceleration signal from which low frequency components are removed is different from an acceleration actually acting on the vehicle. Accordingly, it is an object of the present invention to provide a vehicle control device capable of executing a vehicle control that is practically satisfactory even when the vehicle control is performed using the acceleration signal as described above. Disclosure of the invention

To achieve the above object, a vehicle control device according to the present invention is mounted on a vehicle, and detects an acceleration sensor that detects the magnitude of an acceleration acting on the vehicle; and a low-speed acceleration signal output from the acceleration sensor. A vehicle comprising: a removing unit for removing a frequency component; and a control unit for controlling a control target of the vehicle using at least an acceleration signal from which a low-frequency component has been removed by the removing unit. In the control device, detecting means for detecting that the vehicle state has changed from a state in which a constant acceleration acts on the vehicle to a state in which the acceleration disappears, and when the vehicle state is detected by the detecting means, Correction means for reducing the influence of the acceleration signal on vehicle control until the acceleration signal corresponds to the acceleration actually acting on the vehicle. It is configured to comprise.

With this configuration, when the vehicle state changes from a state where a constant acceleration acts on the vehicle to a state where the acceleration disappears, the acceleration signal output from the acceleration sensor actually acts on the vehicle. Control is performed so as to reduce the influence of the acceleration signal in vehicle control for a predetermined period until the acceleration becomes compatible. As a result, for example, when the road surface on which the vehicle is stopped is inclined, and when a substantially constant acceleration based on the inclination is acting on the vehicle in the stopped state, the vehicle starts from such a state, and the vehicle is driven until then. When the acceleration acting on the Even if an erroneous acceleration signal is output from the stage, the acceleration signal must be used for a certain period until the acceleration signal corresponds to the actual vehicle speed in order to reduce the effect of the acceleration signal in vehicle control. Vehicle control without any problems can be performed. Brief description of the drawings

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, FIG. 2 is a circuit diagram showing the configuration of an acceleration sensor and a processing circuit for removing low-frequency components of the present embodiment, and FIG. Fig. 4 is a characteristic diagram showing the characteristics of the acceleration sensor, Figs. 4 (a), (b) and (c) are flowcharts showing the control flow of the present embodiment, and Figs. 5 (a) and (b), (c) and (d) are explanatory diagrams for explaining the control of the present embodiment, FIG. 6 is a configuration diagram showing a configuration of a conventional acceleration detecting device, and FIG. 7 is an acceleration detecting device shown in FIG. 8 (a) and 8 (b) are flow charts showing the control flow of the second embodiment of the present invention, and FIGS. 9 (a) and 9 (b) are the flowcharts of the present invention. In order to realize the control of the third embodiment, FIGS. 4 (b) and 4 (c) are flow charts showing changes of the flow charts. FIGS. 10 (a) and 10 (b) are flow charts of the present invention. No! FIGS. 4 (b) and 4 (c) are flow charts showing changes of the flow charts to realize the control of the embodiment, and FIGS. 11 (a) and 11 (b) are the first invention and FIG. 2 is a configuration diagram showing an outline of the second invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the suspension device of the vehicle is controlled, and the vehicle control device is applied as the suspension control device.

In FIG. 1, a wheel 10 is connected to a vehicle body via a lower arm 9, and a shock absorber 1 and a coil spring 2 are disposed between the lower arm 9 and the vehicle body. Although Fig. 1 shows the configuration of only one wheel, Fig. 1 shows all four wheels of the vehicle. The configuration shown in FIG.

The shock absorber 1 is connected to the pressure control valve 3, and the hydraulic oil in the shock absorber 1 is controlled by supplying / discharging the hydraulic oil by the pressure control valve 3. The pressure control valve 3 is connected to a pump 7 that compresses and discharges hydraulic oil from a reservoir 8 to a high pressure and is connected to the reservoir 8 via an oil cooler 6. An accumulator 4 for temporarily storing hydraulic oil is connected in the middle of the pipe connecting the pump 7 and the pressure control valve 3. In addition, a relief valve 5 is provided to prevent the oil pressure from excessively increasing due to the pump 7, and when the oil pressure at point C in the figure exceeds a predetermined value, the operation discharged from the pump 7 Reflux the oil to reservoir 8.

Here, the pressure control valve 3 includes a variable throttle valve 3a, a proportional valve 3b, and a fixed throttle valve 3c. The proportional valve 3b continuously changes the flow rate of the hydraulic oil so that the pressure difference between the points A and B in the figure becomes constant. That is, if the amount of throttle of the hydraulic oil of the variable throttle valve 3a is changed, the hydraulic pressure at the point A rises or falls. Therefore, by controlling the amount of throttle, the hydraulic pressure at the point B, ie, the hydraulic pressure of the shock absorber 1 Can be controlled.

The control of the throttle amount of the variable throttle valve 3 a is performed by an electronic control unit (ECU) 11. The ECU 11 receives detection signals from various sensors and outputs a control signal to the variable throttle valve 3a based on the detection signals. Here, a sensor that outputs a detection signal to the ECU 11 is provided in each shock absorber, a height sensor 12 that detects a stroke of the shock absorber 1, a longitudinal direction and a lateral direction of the vehicle. Acceleration sensor 13 for detecting the acceleration acting in the direction, steering sensor 14 for detecting the steering angle, vehicle speed sensor 15 for detecting the traveling speed of the vehicle, engine throttle valve Throttle position sensor 16 that outputs a signal proportional to the degree of opening of the brake pedal. There is a storage switch 17 for detecting, and a pressure sensor 18 provided for each shock absorber and for detecting the oil pressure supplied to the shock absorber 1. The acceleration sensor 13 serves as a processing circuit as a removing means for removing a low frequency component from the acceleration signal. Further, the ECU 11 takes in a signal from the control switch 19 for adjusting the vehicle height operated by the driver.

Based on signals from these sensors and switches, the ECU 11 and the pressure control valve 3 mainly execute the following three types of control.

(1) When a request to adjust the vehicle height is generated by the outlet switch 19, the vehicle height is detected by the height sensor 12 and the detected vehicle height is requested. In order to match the height, the ECU 11 outputs a control signal to the variable throttle valve 3a.

(2) Predict changes in vehicle attitude based on signals from acceleration sensor 13, steering sensor 14, vehicle speed sensor 15, slot sensor 16, and stop lamp switch 17. In order to suppress the change, the ECU 11 outputs a control signal to the variable throttle valve 3a to adjust the hydraulic pressure of each shock absorber.

(3) When the hydraulic pressure of the shock absorber suddenly increases, for example, when the vehicle gets over a bump on the road, the hydraulic pressure at point B increases. Therefore, the proportional valve 3b operates to reduce the oil pressure at point B, that is, the oil pressure of the shock absorber, in order to maintain a constant pressure difference from the pressure at point A, thereby improving the riding comfort.

Here, the acceleration sensor 13 in the present embodiment will be described with reference to the drawings.

In the acceleration sensor 13 according to the present embodiment, if the detected acceleration does not change, it is determined that the currently output acceleration signal is due to the drift, and the sensor is canceled so as to cancel the output. Correct the reference operating point of the amplifier that amplifies the output signal from the circuit. With this, It is possible to detect a change in acceleration up to a lower frequency as compared with a conventional acceleration detection device using an alternating-current power ring without lowering the function of removing the foot.

FIG. 2 shows the configuration of the acceleration sensor 13 in which semiconductor resistors 11 1 and 11 2 are connected together with resistors 12 1 and 12 2 to form a bridge circuit. You. In this case, the resistors 111 and 112 have, for example, a piezoresistive element attached to a vibrating element composed of a semiconductor, and the resistance value of the piezoresistive element is a value proportional to the bending of the vibrating element. Becomes The output signal from the bridge circuit is amplified by the differential amplifier 20 and then input to the inverting input terminal of the operational amplifier (op amp) 22. The output signal of the operational amplifier 22 is output from the output terminal 21 as an acceleration signal and is also input to the comparators 23 and 24. Further, these comparators 23 and 24 are supplied with reference voltages + △ V and — △ V set by resistors R 1 to R 3. Here, the voltage range from + △ V to 10 V corresponds to the state where the acceleration is zero. When the vehicle is under acceleration, the voltage of the signal output from the operational amplifier 22 is Since the value exceeds the above voltage range, the outputs from the comparators 23 and 24 are repeatedly turned on and off at a considerably high frequency.

The output signals from these comparators 23 and 24 are supplied to X0R25, and the output signal from X0R25 is supplied as a set command signal for monostable multivibrator 26. You. The output signal from the monostable multivibrator 26 is inverted by the inverter 27 and supplied to the AND 28. The clock signal from the clock generator 29 is further supplied to the AND 28. Therefore, when the output signal of the monostable multivibrator 26 becomes low level, the clock signal is output from the AND 28.

The output signal from comparators 23 and 24 is the flip-flop circuit 3. Also used as a set and reset command of 0. In other words, when an output signal is generated from the comparator 23, the flip-flop circuit 30 is set, and a countdown command is given to the abduction counter 31. On the other hand, when an output signal is generated from the comparator 24, the flip-flop circuit 30 is reset, and a count-up command is given to the up / down counter 31. The up / down counter 31 is supplied with an output signal from the XOR 25 as an enable signal via the inverter 32, and the output signal of the XOR 25 is supplied to the up / down counter 31. When the high level is reached, the application counter 31 is set to a countable state. In this state, the up / down counter 31 counts the clock signal from AND 28 in response to the count-down or count-down command. Then, the count value data of the counter 31 is converted into a voltage value by the resistance ladder circuit 33, and is then appropriately amplified and input to the non-inverting input terminal of the operational amplifier 22.

With this configuration, if a predetermined acceleration is applied to the vehicle and the same acceleration continues to be applied thereafter, when the acceleration is applied to the vehicle, either one of the connector and the Outputs a high-level signal. When this output signal is input to XOR 25, a high-level signal is output from XOR 25, and the monostable multivibrator 26 is set by this output signal. Outputs a high-level signal. Therefore, the signal supplied to 0 28 via the inverter 27 becomes low level, and the output of the clock signal from the AND 28 is stopped. After that, when the vehicle has a substantially constant acceleration, no new set command is issued to the monostable multivibrator 26, and the time constant of the monostable multivibrator 26 is not changed. When the corresponding predetermined time has elapsed, the output signal of the monostable multivibrator 26 goes low. At this time, since the output signal of XOR 25 still maintains the high level state, the inverter 3 The enable signal supplied to the up / down counter 31 via 2 is at a low level, and the up / down counter 31 can be counted. Therefore, when a clock signal is supplied from AND 28, the up / down counter 31 corresponds to the power-up or count-down signal from the flip-flop circuit 30. Counting. Then, the voltage signal from the resistance ladder circuit 33 corresponding to the count value of the up / down counter is input to the operational amplifier 22 to reduce the deviation from the voltage signal output from the sensor circuit. the correction _e of the reference operating point of the reference operating point is corrected to the voltage value of the output signal from the op amp 2 2 assumes a value within the voltage range of up to + AV, comparator 2

The output signals of 3 and 24 are both at the mouth level. As a result, the signal output from XOR 25 becomes high level, the enable signal input to up counter 31 becomes high level, and counting of up / down counter 31 stops. I do. By such an operation, when a substantially constant acceleration acts on the vehicle, the acceleration signal output from the output terminal 21 is as shown in FIG.

Then, as shown in Fig. 3, when the acceleration acting on the vehicle disappears, in the presence of this acceleration, the operational amplifier is set so that the acceleration signal output from the output terminal 21 becomes zero. Since the reference operating point 2 was captured, when the acceleration disappeared, an acceleration signal was output as if an acceleration in the opposite direction to the acceleration that was acting on the vehicle was applied. You.

If the acceleration acting on the vehicle is not changed, the reference signal of the operational amplifier 22 is corrected by the same operation as described above, so that the acceleration signal gradually approaches zero.

FIGS. 4 (a), 4 (b) and 4 (c) show flow charts for controlling a vehicle suspension device using such an acceleration sensor 13. FIG.

In Fig. 4 (a), when the vehicle starts moving, the acceleration signal Is shown in the flowchart for compensating to zero. Here, if the vehicle is parked at an angle, for example, when the vehicle is parked with one wheel riding on the shoulder, as shown in Fig. 5 (a), even if the vehicle is parked, A predetermined acceleration is acting on both. When the vehicle starts running from this state, when the acceleration disappears, the acceleration sensor 13 returns from the acceleration sensor 13 in the direction opposite to the acceleration acting on the vehicle as shown by the dotted line in FIG. 5 (a). Is output. For this reason, it is detected that the vehicle has started, and in the start state of the vehicle, a predetermined time T longer than the time t until the reverse acceleration signal approaches zero. Correct the acceleration signal value to zero. Therefore, for example, if the acceleration signal output from the acceleration sensor 13 is used as it is for suspension control, the vehicle may run while leaning due to an incorrectly output reverse acceleration signal. Although a problem arises, by performing suspension control using the corrected acceleration signal, it is possible to realize practically trouble-free control.

In FIG. 4 (a), initial processing is performed in step 410, and necessary flags and counters are initialized. In step 415, detection signals from each sensor and switch are fetched. In step 417, the detected acceleration _Gn taken in step 415 is set as the acceleration signal G. In step 420, it is determined whether or not the counter CN1 is zero. If not, the flow proceeds to step 430. At step 430, the value of counter CN1 is decremented by 1, and at step 440, acceleration signal G is set to zero. That is, the counter CN 1 plays a role as a timer for setting a time for correcting the acceleration signal G to zero.

If it is determined in step 420 that the counter CN1 is zero, the flow advances to step 450 to determine whether or not the flag FLG0 is zero. At this time, if the flag FLG 0 is zero, Then, it is determined whether or not the vehicle speed signal SPD output from the vehicle speed sensor 15 is higher than the set vehicle speed V ₀ , (for example, 5 km / h). The vehicle speed signal SPD is the set vehicle speed V. If it is greater than the value, proceed to step 470, set the value of flag FLG0 to 1 and set the value of counter CN1 to T. Set to. The value T of the counter CN1 set in this step 470. Is longer than the time when the acceleration signal G detected when the vehicle is parked leaning and the acceleration applied at that time disappears is approaching zero, and the value of the acceleration signal G is corrected to zero. (For example, 20 seconds). Then, the value T set for this counter CN1. The acceleration signal G is corrected to zero by the above steps 420-440 during the time corresponding to In step 460, the vehicle speed signal SPD is equal to the set vehicle speed V. If it is determined that the vehicle speed is below, the process proceeds to step 480 where the vehicle speed signal SPD is equal to the set vehicle speed V. And the acceleration signal G is corrected to zero until it is determined that the vehicle is in the starting state. That is, the flag FLG 0 indicates that the ignition switch is turned on and the vehicle speed signal SPD is the set vehicle speed V. At this point, it is determined that the vehicle has started and its value is set to 1. Then, after the value of the flag FLG0 becomes 1, the processing of steps 460 to 480 is performed by the determination processing of step 450, that is, the acceleration signal G is generated when the vehicle is in the starting state. The process of correcting to zero is omitted. In other words, the flag FLG 0 is used to always correct the acceleration signal G to zero when the vehicle has started.

In Fig. 4 (b), there is shown a front chart for correcting the acceleration signal to zero when the vehicle changes from a stopped state to a start state with the engine running. I have. In other words, as shown in FIG. 5 (b), it is detected from the acceleration acting on the vehicle when the vehicle is stopped that the vehicle has stopped, for example, by leaning on one of the wheels on the road shoulder. Then, when starting from this state, the start state is detected and a predetermined time T is set. During Correct the value of the acceleration signal to zero. As a result, even when the vehicle is shifted from a state in which the vehicle has been stopped by leaning to a state in which the vehicle starts moving, control that is practically free from problems can be realized.

In FIG. 4 (b), in step 490, it is determined whether or not the value of the counter CN1 is zero, and if not, the routine exits. This is because when the value of the counter CN1 is not zero, the process of correcting the acceleration signal G to zero is continued by the flow chart shown in FIG. 4 (a). In step 490, when the value of the counter CN1 is zero, the routine proceeds to step 500, where it is determined whether or not the flag FLG1 is zero. At this time, if the flag FLG1 is zero, the process proceeds to step 510, where the absolute value of the acceleration signal G is the reference acceleration G for determining that the vehicle is leaning when stopped. (For example, 0.05 G). The absolute value of the acceleration signal G is the reference acceleration G. When the absolute value of the acceleration signal G is smaller, the process proceeds to step 520. If the absolute value of the acceleration signal G is smaller, the process proceeds to step 590. In step 520, it is determined whether or not the vehicle speed signal SPD is higher than the reference vehicle speed V, which determines whether the vehicle is stopped (for example, 5 km Zh), and the vehicle is stopped with the vehicle speed signal SPD being larger. If not, go to step 590. In step 590, the flag FLG1 is set to zero, the value of the counter CN2 is also set to zero, and the routine exits. On the other hand, when the vehicle speed signal SPD is smaller in the determination result of step 520, the process proceeds to step 530, and the value of the counter CN2 is incremented by one. In step 540, it is determined whether or not the value of the counter CN2 has become larger than the predetermined time T, (for example, 2 seconds), that is, the time during which the vehicle is leaning and stopping is maintained for the predetermined time T, Is determined. At this time, if the value of the counter CN 2 is larger than the predetermined time T, the flow advances to step 550 to set the value of the flag FLG 1 to 1. Here, when a substantially constant acceleration is acting on the vehicle, the acceleration signal output from the acceleration sensor 13 gradually increases. When it is detected that the vehicle is leaning and stopped for a predetermined time because it approaches zero, the value of the flag FLG 1 is set to 1 when it is detected that the vehicle has continued for a predetermined time, T, and step 5 By the discrimination process at 0 0, the determination of the vehicle inclination based on the acceleration signal G at the subsequent step 5 10 is prohibited.

In step 560, the value of the counter CN2 is compared with a reference time _Tz (for example, 20 seconds) for determining that the vehicle has stopped, so that the vehicle may have stopped for a short time. Ku, it is determined whether Taka stopped reference time T ₂ or more. When the vehicle has been stopped for the reference time _{ζ ζ} or more, the process proceeds to step 570 to set the values of the flags FLG 0 and FLG 1 and the counter CN 2 to zero. In step 580, the value of the acceleration signal G is set to zero until the vehicle starts running again. Then, in step 570, the value of the flag FLG0 is reset to zero again, so that the processing of the flowchart shown in FIG. 4 (a) is executed again, and the vehicle changes from the stopped state to the start state. The predetermined time T set by the counter CN 1 when it becomes true. The acceleration signal G is corrected to zero.

Incidentally, in Step 5 6 0, in place of the vehicle is whether the vehicle stops reference time T ₂ above determination process, the time is stopped to tilt the vehicle during a predetermined time T, it is detected that continues Then, when the value of the flag FLG 1 is set to 1, the processing of steps 570 and 580 may be executed. In this case, the processing in step 500 can be omitted.

FIG. 4 (c) shows a flow chart for correcting the acceleration signal to zero when the vehicle changes from a state where the vehicle is making a steady turn to a straight state. Here, as shown in FIG. 5 (c), when the vehicle is making a steady turn while maintaining a substantially constant speed and turning radius, a substantially constant acceleration acts on the vehicle. If such a state continues for a predetermined time, the acceleration signal output from the acceleration sensor 13 is indicated by a dotted line in FIG. 5 (c). As it approaches, it gradually approaches zero. Further, when the specialist returns to the straight traveling state from such a state, the acceleration sensor 13 outputs an acceleration signal in a direction opposite to the acceleration actually acting on the vehicle. In the present embodiment, the output of the acceleration signal in the opposite direction is detected, and the acceleration signal is corrected to zero. Therefore, if the corrected acceleration signal is used for controlling the suspension device, it is possible to perform control without practical problems.

In FIG. 4 (c), in step 600, as in step 490, it is determined whether or not the value of the counter CN1 is zero, and if it is not zero, the routine exits. In Step 6 1 0, a vehicle speed signal SPD is, the vehicle is greater or not than the determining reference speed V ₂ that is traveling (e.g., 2 0 km / h) is determined, the reference speed vehicle speed signal SPD is When it is larger than V z, go to step 62. In step 62, the absolute value of the roll angle ø based on the detection signal from the height sensor 12 is equal to the reference roll angle ς & 0 (for example, when the difference between the left and right wheels is 2) to determine that the vehicle has a mouth. The absolute value of the roll angle ø is 0, which is the reference roll angle. If it is larger than the above, the process proceeds to step 630. Here, in the present embodiment, when a roll occurs when the vehicle turns, the posture control is performed to suppress the roll. However, this attitude control does not aim to make the roll zero, and a slight roll occurs when the vehicle turns. Therefore, it is possible to detect that the vehicle is in a turning state from the detection signal from the height sensor 12. In step 630, it is determined whether or not the direction of the roll generated on the vehicle and the direction of the acceleration signal G correspond correctly. If the two directions do not correspond to each other, the process proceeds to step 64. In step 64, it is determined whether or not the absolute value of the acceleration signal G output in the reverse direction is greater than a predetermined threshold value G, (for example, 0.1 G). When the absolute value is larger than the predetermined threshold value G, the process proceeds to step 65. In step 60, counter C The value of N 3 is 1 Dzu'i link Li e n t, the value of Step 6 6 0 Nioiteko »Ka c printer CN 3 is, whether greater than a predetermined reference time T ₄ (for example 4 0 ms ec) Is determined, and when the value of the counter CN3 is large, the process proceeds to step 670. Here, the fact that the value of the counter CN 3 is larger than the reference time T ₄ means that the vehicle is running and a roll is generated in the vehicle. direction coincides Orazu, is as shown in FIG. 5 (d) to al, between absolute value a predetermined threshold value G, from greater state reference time of the acceleration signal G T _4, continued At this time, it is determined that the vehicle has changed from a steady turning state to a straight running state. (In addition, in FIG. 5 (d), the portion surrounded by the dotted line X in FIG. 5 (c) is enlarged. Is shown). Then, in step 670, the acceleration signal G in the reverse direction output when the maximum roll occurs in the vehicle is corrected so that the acceleration signal G is corrected longer than the time when it approaches zero. The value T ₃ (for example, 60 seconds) is set in the counter CN 1. In Step 6 8 0, time corresponding to the counter CN value T ₃ set to 1, the acceleration signal G until is corrected to zero, to zero compensation acceleration signals G.

In step 690, the change in the attitude of the vehicle is predicted using the acceleration signal G corrected by the above processing, and the control of the above-described suspension device is executed to suppress the change in the attitude.

In the above-described embodiment, when the vehicle starts from a state in which the vehicle is parked or stopped, or when the vehicle changes from a steady turn to a straight-ahead state, the predetermined time set by the counter C # 1. Only T _3, and corrects the zero acceleration signals G. However, always at a given time Τ. , T ₃ only acceleration signal G zero rather than ToTadashi to the vehicle of the left and right wheels of the variable throttle valve 3 times with approximately equal Naruma magnitude of the braking No.铷信to be output to a (i.e. The time until the control signal difference between the variable throttle valves 3a of the left and right wheels falls within a predetermined value may be set. In other words, left and right wheels The magnitude of the control signal output to the variable throttle valve 3a becomes substantially equal, the hydraulic pressures in the shock absorbers 1 provided for the left and right wheels become substantially equal, and the vehicle attitude substantially matches the road surface. This is because there is no need to correct the acceleration signal G because it is parallel to each other.

Furthermore, the time for correcting the acceleration signal G to zero is determined by detecting the pressure value of each shock absorber 1 by the pressure sensor 18 provided in each shock absorber 1, and the hydraulic pressure of the left and right wheels is almost equal. It may be time until it becomes.

Further, the time for correcting the acceleration signal G to zero may be the time until the acceleration signal G output from the acceleration sensor 13 is detected and the acceleration signal G becomes substantially zero.

Next, a second embodiment of the present invention will be described.

In the above-described embodiment, the value of the acceleration signal G is always corrected to zero when the vehicle changes from a parked state to a start state. On the other hand, in the second embodiment, when the vehicle changes from the parked state to the start state, it is determined whether or not the vehicle is parked in an inclined state, and the vehicle is parked in an inclined state. Only when is the value of the acceleration signal G corrected to zero.

Figures 8 (a) and 8 (b) show flowcharts for implementing the above control. The flow charts shown in FIGS. 8 (a) and 8 (b) are partially modified from those shown in FIGS. 4 (a) and 4 (b) (steps 4 ′ and 4 ′). 1 1, 4 1 2, 5 5 0 ′) Therefore, only the modified steps will be described below.

In FIGS. 8 (a) and 8 (b), if it is determined in step 540 that the value of the counter CN2 is longer than the predetermined time, the time during which the vehicle is tilted and stopped is the predetermined time T. ! Is continuing. At this time, in this embodiment, the value of the flag FLG 1 is set to 1 in step 550 ′, and the value of FLG 2 is also set to 1. And these hula The values of FLG 1 and FLG 2 are stored in the ID switch (the memory that does not erase the contents even when the IG switch is turned off. Therefore, the IG switch is turned off in this state). When the vehicle is parked and then the IG switch is turned on again, it is detected by referring to the value of the flag FLG2 that the vehicle is parked in an inclined state. Can be.

In the initial processing in step 4 10 ', the value of flag FLG is set to 1, the value of flag FLG 1 is set to zero, and the values of counters CN 1, CN 2, and CN 3 are also set to zero. Is done. Then, in step 411, it is determined whether or not the value of the flag FLG2 stored in the memory is zero. If the result of this determination is that the value of the flag FLG2 is 1, the process proceeds to step 412, where both the value of the flag FLG0 and the value of the flag FLG2 are set to zero. Here, when the value of FLG0 is zero, the acceleration signal G is set to the predetermined time T when the vehicle is in the starting state. Corrected to zero. In the above-described embodiment, the flag FLG0 is set to zero in the initial processing of step 410, and the acceleration signal G is always corrected to zero when the vehicle is in the starting state. . On the other hand, in the second embodiment, the fact that the vehicle is parked in an inclined state is detected from the value of the flag FLG2, and the acceleration signal G is corrected to zero only when the vehicle starts from such a state. I am trying to do it.

Next, a third embodiment of the present invention will be described.

In the above-described embodiment, the absolute value of the acceleration signal G is the reference acceleration G, as shown in step 5100 of FIGS. 4 (b) and 8 (b). If it was larger, it was judged that the vehicle was leaning and stopped. Further, as shown in step 62 of FIG. 4C, the absolute value of the roll angle based on the detection signal from the noise sensor 12 is the reference roll angle 0. When it is larger than, it was determined that the vehicle was turning and the vehicle was turning. On the other hand, in the third embodiment, the stains shown in FIGS. 4 (b) and 8 (b) are used. Step 5110 is changed as shown in FIG. 9 (a). Further, step 62 in FIG. 4 (c) is changed as shown in FIG. 9 (b). In this modified step 5 10 ′, the control signals I (left) and I (left), which are given to the left and right wheels, respectively, are based on the control signal I for the variable throttle valve 3 a of the pressure control valve 3 provided for each wheel of the vehicle. (Right) The difference between the magnitudes is the reference value I that determines the inclination of the vehicle. It is determined whether it is larger than. That is, when the vehicle stops at an angle, there is a difference between the loads applied to the left and right wheels. At this time, in this embodiment, control is performed so that the pressure in the shock absorber on the wheel side to which a large load is applied is high, and the pressure in the shock absorber on the other wheel side is low. Therefore, when there is a difference between the magnitudes of the control signals I (left) and I (right) given to the variable throttle valves 3a for the left and right wheels, the vehicle is in a state of being inclined in the left-right direction. It is. Therefore, in the third embodiment, it is detected whether or not the vehicle is tilted when the vehicle stops, based on the control signals I (left) and I (right) given to the left and right wheels, respectively.

Also, at step 62 'shown in FIG. 9 (b), the vehicle is controlled based on the difference between the magnitudes of the control signals I (left) and I (right) for the variable throttle valves 3a of the left and right wheels. It is determined whether the vehicle is turning.

In the third embodiment, when determining the correspondence between the roll direction and the direction of the acceleration signal G in step 630 of FIG. Judgment is made from the magnitude of the control signals I (left) and I (right) for the throttle valve 3a. Also, in the third embodiment, instead of the control signal I given to the variable throttle valve 3a of each wheel, the detection signal of the pressure sensor 18 for detecting the hydraulic pressure of the shock absorber 1 of each wheel is used. May be used.

Next, a fourth embodiment of the present invention will be described.

In the fourth embodiment, as shown in step 485 of FIG. 10 (a), the vehicle speed signal detected by the vehicle speed sensor 15 and the steering sensor 1 4 based on the steering angle signal detected by obtaining the estimated acceleration G _c acting on the vehicle. Then, as shown in Step 5 1 0 ', determines whether the absolute value and the acceleration signal whether the difference is greater than the reference value K of the absolute value of G for the estimated acceleration G _c. As a result, the estimated acceleration G c becomes almost zero because the traveling speed of the vehicle is extremely low, for example, when the vehicle rides one wheel on the road shoulder and stops. On the other hand, the acceleration signal G has a value corresponding to the inclination of the vehicle. Therefore, by comparing the difference between the absolute value of the estimated acceleration G c and the absolute value of the acceleration signal G with the reference value K, it is possible to detect that the vehicle is leaning and stopped. In addition, as shown in step 62 0 ′ of FIG. 10, by comparing the absolute value of the difference between the estimated acceleration G c and the acceleration signal G with the reference value G _z , the vehicle becomes stationary. It can detect that the vehicle is turning. That is, when the vehicle is making a steady turn, a substantially constant acceleration acts on the vehicle. Therefore, the acceleration signal G gradually approaches zero, and the difference from the estimated acceleration Gc increases. If the difference between the acceleration signal G and the estimated acceleration Gc becomes larger than the reference value, it can be determined that the vehicle has made a steady turn for a predetermined time.

In the above-described embodiment, when the vehicle starts from a state where the vehicle is parked or stopped, or when the vehicle changes from a steady turn to a straight-ahead state, an erroneous acceleration signal G is detected. By compensating to zero, the influence of the acceleration signal G on suspension control is reduced. However, when an erroneous acceleration signal G is detected, an amplifier capable of reducing the weight of the acceleration signal G in predicting a change in the attitude of the vehicle or changing the amplification factor is provided. By reducing the amplification rate of the acceleration signal G, the influence of the acceleration signal G on suspension control may be reduced.

In the above-described embodiment, an example in which the control target is a suspension device and the present invention is applied to a suspension control device has been described. In addition, the present invention can be applied to a case where control is performed using an acceleration signal such as an anti-lock brake system (ABS) and a steering device as a control target. Industrial applicability

As described above, the vehicle control device according to the present invention is very effective for a device that performs vehicle control based on a signal after removing a low-frequency component of an acceleration signal output from an acceleration sensor. Examples of the device include an active suspension antilock brake system and a steering device.

Claims

The scope of the claims

1. An acceleration sensor that is mounted on a vehicle and detects the magnitude of acceleration acting on the vehicle, a removing unit that removes a low-frequency component of an acceleration signal output from the acceleration sensor, and at least A vehicle control device comprising: a control unit configured to control a control target of the vehicle using the acceleration signal from which the low frequency component has been removed by the removal unit.

Detecting means for detecting that the vehicle state has changed from a state in which a constant acceleration acts on the vehicle to a state in which the acceleration disappears;

When the vehicle state is detected by the detection means, the influence of the acceleration signal on vehicle control is reduced until the acceleration signal corresponds to the acceleration actually acting on the vehicle. Control device comprising correction means

2.The detection means includes a stop detection means for detecting that the vehicle has stopped in a tilted state, and a start detection means for detecting that the vehicle has shifted from a stop state to a start state,

When the stop detecting means detects that the vehicle has stopped in a tilted state, and when the start detecting means detects that the vehicle has shifted from a stopped state to a start state, 2. The vehicle control device according to claim 1, wherein the correction unit corrects the acceleration signal.

3. The stop detecting means includes a speed detecting means for detecting a traveling speed of the vehicle, and a timer means for detecting a continuous time,

When the timer means detects that the state in which the traveling speed of the vehicle is equal to or lower than a predetermined speed and the acceleration signal output from the acceleration sensor is equal to or higher than a predetermined acceleration is continued for a predetermined time. The vehicle control device according to claim 2, wherein the stop detection means detects that the vehicle has stopped in an inclined state.

The control object regulates the fluid pressure supplied to the shock absorber. Controlling the posture of the vehicle Te is Akti Busasupensho down,.. _¾ said stop detecting means, based on the size difference between the adjustment signal of the fluid pressure against the sucrose Kkuabusoba left and right wheels of the vehicle, said vehicle 3. The vehicle control device according to claim 2, wherein the vehicle control device detects that the vehicle has stopped in an inclined state.

5. The stop detecting means includes: a speed detecting means for detecting a running speed of the vehicle; a steering sensor for detecting a steering angle of the vehicle; a running speed detected by the speed detecting means; Calculating means for calculating an estimated acceleration acting on the vehicle based on the steering angle detected by the steering sensor;

The stop detecting means detects that the vehicle has stopped in a tilted state based on a difference between an estimated acceleration calculated by the calculating means and an acceleration signal output from the acceleration sensor. The vehicle control device according to claim 2, wherein:

6. The detecting means is a portal detecting means for detecting that a roll has occurred in the vehicle, and the direction of the roll generated in the vehicle correctly corresponds to the direction of the acceleration signal output from the acceleration sensor. Determination means for determining whether or not

When the roll detecting means detects that a roll has occurred in the vehicle, and when the discriminating means detects that the direction of the roll does not correctly correspond to the direction of the acceleration signal, the correcting means 2. The vehicle control device according to claim 1, wherein the vehicle control device corrects the acceleration signal.

(7) The roll detecting means includes: a height sensor that detects a stroke of a shock absorber of the left and right wheels of the vehicle; a roll angle calculated based on the stroke detected by the height sensor; and a reference roll angle. And comparing means for comparing

The roll detection means includes a roll angle calculated by the comparison means. 7. The vehicle control device according to claim 6, wherein, when is larger than the reference roll ¾, the occurrence of a roll in the vehicle is detected.

8. The object to be controlled is an active suspension that controls the attitude of the vehicle by adjusting the fluid pressure supplied to the shock absorber,

The roll detecting means detects that a roll is generated in the vehicle based on a difference in the magnitude of an adjustment signal of a flow rest pressure with respect to a shock absorber for left and right wheels of the vehicle. The vehicle control device according to claim 6, wherein

9. The roll detecting means includes: a speed detecting means for detecting a running speed of the vehicle; a steering sensor for detecting a steering angle of the vehicle; a running speed detected by the speed detecting means; Calculating means for calculating an estimated acceleration acting on the vehicle based on the steering angle detected by the sensor.

The roll detection means detects that a roll has occurred in the vehicle based on a difference between an estimated acceleration calculated by the exercise means and an acceleration signal output from the acceleration sensor. The vehicle control device according to claim 6, wherein:

10. An acceleration sensor mounted on a vehicle for detecting the magnitude of acceleration acting on the vehicle, a removing unit for removing a low-frequency component of an acceleration signal output from the acceleration sensor, and at least A vehicle control device comprising: a control unit configured to control a control target of the vehicle using the acceleration signal from which the low-frequency component has been removed by the removal unit;

Detecting means for detecting the start state when the state of the vehicle shifts from a stop state to a start state;

When the detecting means detects the starting state of the vehicle, a signal for reducing the influence of the acceleration signal on vehicle control until the acceleration signal corresponds to the acceleration actually acting on the vehicle. A vehicle control device comprising: a forward correction means.