JPH0764222B2 - Vehicle attitude control device - Google Patents

Description

The present invention relates to a vehicle attitude control device, and more specifically,
The present invention relates to an attitude control device for a vehicle, in which an auxiliary steering device is provided separately from the main steering device for the vehicle to control the attitude of the vehicle in a desired direction.

[Conventional technology and its problems]

BACKGROUND ART Conventionally, there is a four-wheel steering vehicle as one of vehicle attitude control devices ("A Study on Electronically Controlled Adaptive Seyaw Angular Speed Steering System for Rear Wheel Actual Steering Angle", Kanai, Uchimon, et al., 7th Applied Control Symposium Proceedings, published in February 1982). This four-wheel steering vehicle
As shown in FIG. 2, first, an auxiliary steering mechanism 61 including a hydraulic cylinder 67 and a hydraulic control device 68 for controlling the cylinder 67 is provided on the rear wheel. Next, the vehicle speed and the main steering angle of the front wheels are measured by the detectors 62 and 63, and a desired yaw rate value of the vehicle body is calculated and commanded by the circuit 4 from the measured values.
Next, the difference between this command value and the actual value of the yaw rate detected by the gyro 65 is calculated. Next, the circuit 66 calculates the auxiliary steering angle from the deviation of the yaw rate, and commands the control device 68 of the auxiliary steering mechanism 61. This allows the hydraulic cylinder 67
Activates and changes the direction of the rear wheels. With the above-described configuration, in this four-wheel steering vehicle, for example, when side wind disturbance is applied and the vehicle body moves in a direction different from the direction intended by the driver, the auxiliary steering mechanism 61 operates and the posture should be as it should be. It is said that it can be rebuilt in the direction.

However, in this four-wheel steering vehicle, cross wind is applied to the vicinity of the front wheels as shown in FIG. 3 (arrow A) with respect to the running vehicle. When the rear wheels are steered clockwise to cancel the clockwise moment due to the crosswind (arrow B), side force is generated in the direction of arrow C in the figure, and the yaw rate generated by the crosswind is suppressed and Lateral force in the vertical direction of the figure is newly generated by the side force. For this reason,
Although the rotation of the vehicle body is suppressed, parallel movement in the lateral direction is promoted to the contrary, which gives the driver anxiety. In addition, if the auxiliary steering mechanism fails and cannot move, the rear wheels are likely to be fixed in a certain direction, which is dangerous.

Further, as another one of the above-mentioned conventional techniques, there is an "omnidirectional moving carriage" (Japanese Patent Laid-Open No. 60-146757). As shown in FIG. 4, this omnidirectional mobile trolley is provided with four motors M1 each for steering. Next, the motor M2 is provided on each of the left and right drive wheels to drive the vehicle. Control target value calculation circuit 70
Reads the position of the joystick 71, and commands the direction to travel and the traveling speed. The rotation angle calculation circuit 72 calculates the rotation angle of the motor M1 based on the command value in the traveling direction and issues a command. Based on this command value, the arithmetic circuit 73 calculates the required value of the motor current and commands the four motor control devices 74. On the other hand, the rotation speed calculation circuit 75 for the left and right motors calculates and commands the rotation speed of the motor M2 based on the command value of the traveling speed.
Further, the arithmetic circuit 76 calculates the corrected rotational speeds of the left and right drive wheels necessary for making the value of the yaw rate detected by the gyro 77 zero. The adder 78 gives a command to the two motor control devices 80 via the motor voltage command value calculation circuit 79 as the final number of rotations of the left and right motors M2 by adding the output signals of the calculation circuits 75 and 76. .

The operation of the control device for the moving carriage is as follows. That is, if there is no disturbance, the motor
Since the left and right rotation speeds of M2 are equal, the motor M1 moves straight in a direction defined by the motor M1 at a desired speed (zero yaw rate). Here, when the orientation of the vehicle deviates from the desired orientation due to irregularities on the road surface or the like, a yaw rate occurs, which causes a difference in rotational speed between the two motors M2. Therefore, the yaw rate is suppressed to zero, and the vehicle can travel in the originally defined direction. As a result, in this moving dolly, the left and right drive motors try to restore the posture by making a difference in the number of rotations, so that an extra lateral force generated by the control such as that of the four-wheel steering vehicle described above as the prior art is generated. There are no shortcomings.

However, since this moving carriage is a mechanism that also corrects the direction by the driving wheels, there is a new drawback that the controllable range becomes narrow due to the interference between the driving force control system and the attitude control system. For example, when it is requested to travel at the maximum speed, the driving force of the driving wheels is naturally increased to the grip limit of the road surface. In this state, if a new driving force is added to correct the direction, the wheels will exceed the grip limit and control will be lost. Therefore, there is a problem that the range in which the posture control is possible becomes narrower as the traveling speed of the vehicle becomes higher.

Therefore, the inventors of the present invention have earnestly studied in order to solve the above-mentioned problems of the prior art, and as a result of various systematic experiments, the present invention has been accomplished.

[Object of the Invention]

An object of the present invention is to provide a vehicle auxiliary steering control device that is safe and has a wide controllable range without generating an undesired lateral force during posture control.

The present inventors have focused on the following problems with respect to the above-mentioned problems of the conventional technology. That is, the driver tries to control the vehicle to a desired posture by steering. Therefore, it is considered that the steering angle is proportional to the behavior amount such as the yaw rate of the vehicle desired by the driver. However, the proportional constant depends on the vehicle speed. Generally, the responsiveness of a behavior amount such as a yaw rate to the steering angle is sharp at high speed and becomes dull at low speed. Therefore, as the vehicle speed increases, the proportional constant should be decreased to set the target behavior amount to be small for the same steering angle. From the above, by detecting two quantities, steering angle and vehicle speed, the target behavioral quantity is calculated as the behavioral quantity desired by the driver and output as the target value for control, and a behavioral quantity detection sensor such as a gyro is used. A control force is generated according to the deviation between the measured behavioral amount such as the yaw rate and the target value, and a driving force difference is generated in the motors provided on the left and right wheels of the non-driving wheels of the vehicle to generate a difference in the vehicle body. The inventors have focused on solving the main problems of the prior art by controlling the posture of the vehicle in a desired direction by adding a moment.

[Explanation of the Invention]

The vehicle attitude control device of the present invention, as shown in FIG.
An attitude control device for controlling an attitude of a vehicle by providing an auxiliary steering device separately from a main steering device of a vehicle, and a steering angle sensor 1 for detecting a steering angle of a steering wheel, and a vehicle speed sensor 2 for detecting a speed of the vehicle. , A behavior sensor 3 for detecting the behavior amount of the vehicle
And a target behavioral amount calculation for computing an optimal target behavioral amount in consideration of the disturbance acting on the vehicle or the vehicle state from the steering angle signal output from the steering angle sensor 1 and the vehicle speed signal output from the vehicle speed sensor 2. Means 10 and means for calculating the target behavior amount
Deviation calculation means 21 for calculating the deviation between the target behavioral quantity signal output from 10 and the detected behavioral quantity signal output from the behavior sensor 3, and based on the behavioral quantity deviation signal output from the deviation calculation means 21 A correction amount calculating means 22 for calculating a correction amount equivalent to the behavior amount deviation, and a driving force or a braking force necessary for correcting and controlling the vehicle attitude based on the correction amount signal output from the correction amount calculating means 22, Alternatively, it is supplied to the motor on the basis of a control amount calculation unit 20 including a motor command value calculation unit 23 for calculating a control amount commensurate with the driving force and the braking force, and a motor command signal output from the control amount calculation unit 20. A first motor control device 31 and a second motor control device 32 for adjusting electric power to be supplied, and a power supply source connected to the first motor control device 31 and the second motor control device 32 to supply electric power to the motor.
A drive means 30 including a drive means 30 and a continuously variable control of the torque of the shaft of the left driven wheel of the driven wheels to which the power of the propulsion prime mover of the vehicle is not directly transmitted, based on the electric power controlled by the drive means 30. A second motor for continuously variably controlling the torque of the shaft of the right driven wheel of the driven wheels to which the power of the propulsion prime mover of the vehicle is not directly transmitted, based on the electric power controlled by the first motor 41 and the driving means 30. The control force is generated according to the deviation of the detected behavior amount from the target behavior amount in consideration of the disturbance acting on the vehicle or the vehicle state, and the vehicle attitude is controlled in a desired direction. It is a feature.

The operation and effect of the present invention having the above configuration are as follows. That is, the present invention is an attitude control device for controlling an attitude of a vehicle by providing an auxiliary steering device separately from a main steering device of a vehicle. First, a steering angle sensor 1 detects a steering angle at a steering wheel to determine a steering angle. Is converted into an electric signal or the like. Further, the vehicle speed sensor 2 detects the vehicle speed and converts it into an electric signal or the like corresponding to the vehicle speed. Also,
The behavior sensor 3 detects the amount of change in vehicle behavior such as yaw rate and lateral speed, and converts it into an electric signal or the like corresponding to the amount of change in behavior.

Then, in the target behavioral amount calculating means 10, the steering angle signal output from the steering angle sensor 1 and the vehicle speed signal output from the vehicle speed sensor 2 are optimized in consideration of the disturbance acting on the vehicle or the vehicle state. The amount is calculated and output as the control target value.

Then, in the control amount calculation means 20, first, the deviation calculation means 21 calculates the deviation between the target behavior amount signal output from the target behavior amount calculation means 10 and the detected behavior amount signal output from the behavior sensor 3. To do. Next, the correction amount calculation means 22
At, the correction amount equivalent to the behavior amount deviation is calculated based on the behavior amount deviation signal output from the deviation calculating means 21. Next, in the motor command value calculation means 23, a control amount commensurate with the driving force and / or the braking force necessary for correcting and controlling the vehicle attitude based on the correction amount signal output from the correction amount calculation means 22 is calculated, A motor command signal is output as the output of the control amount calculation control means 20.

Then, based on the motor command signal which is the output of the control amount calculation control means 20, in the drive means 30, the first motor control device 31 and the second motor control device 32 adjust the electric power supplied to the motor. In the first motor 41 and the second motor 42, the control force corresponding to the deviation of the detected behavior amount from the target behavior amount in consideration of the disturbance or the vehicle state acting on the vehicle to the driven wheels to which the power of the vehicle propulsion prime mover is not directly transmitted is provided. The first motor 41 and the second motor 42 are driven so as to be applied.

The power supply source 33 of the driving means 30 is connected to the first motor control device 31 and the second motor control device 32 to supply electric power to the motor.

Then, depending on the magnitude of the behavior amount calculated by the target behavior amount calculation means 10 and the magnitude of the behavior amount detected by the behavior sensor 3, the following actions are performed.

i) When the behavior amount calculated by the target behavior amount calculating means 10 and the behavior amount detected by the behavior sensor 3 match, the output of the control amount calculating means 20 becomes zero, and the motors 41 of the driven wheels 51, 52,
42 does not generate torque.

ii) When the behavior amount detected by the behavior sensor 3 is larger than the behavior amount calculated by the target behavior amount calculating means 10, a negative signal is generated at the output of the deviation calculating means 21, and the correction amount calculating means is generated by this signal. 22 calculates the moment required to suppress the amount of movement of the vehicle. This moment is generated by two motors 4
It is proportional to the torque difference between 1 and 42. Motor command value calculation means 23
Then, first, in order to make this torque difference, two motors 41,
42 determines the torque to be shared. For example, normally, a drive torque and a braking torque that are half the torque difference are commanded,
Both may be driving torque or braking torque. Next, the voltage or current of the two motors 41 and 42 required to generate this command torque is calculated according to the type of motor used. Based on this specified value, the voltage / current control circuit, chopper, used in normal motor control
A predetermined torque is exerted by the action of a power regulator such as an inverter, which adds a moment to the vehicle,
By controlling the amount of behavior, the desired amount of behavior is approached.

iii) When the behavior amount detected by the behavior sensor 3 is smaller than the behavior amount calculated by the target behavior amount calculating means 10, a positive signal is generated at the output of the deviation calculating means 21, and the correction amount calculating means is generated by this signal. 22 calculates the moment required to increase the amount of movement of the vehicle. This moment is
Similar to the case of i), this moment is added to the vehicle by the torque difference between the two motors 41 and 42, and the desired behavior amount is approximated by increasing the behavior amount.

As described above, when a behavior amount larger than the behavior amount desired by the driver occurs in the vehicle due to a disturbance such as a side wind, the moment newly added by the two motors suppresses the behavior amount and the vehicle is disturbed by the disturbance. Can be restored to its original orientation.

On the contrary, when the responsiveness of the posture change of the vehicle to the driver's steering deteriorates, such as when the vehicle has a heavy load, the moment added by the motor accelerates the amount of movement, so the driver is responsive. It is possible to drive with the same steering feeling as in normal times without experiencing the deterioration of the vehicle.

Furthermore, if the target behavioral amount is set to exceed the behavioral amount that should be obtained by steering the main steering device, the auxiliary moment of the motor can provide turning performance that exceeds the original characteristics of the vehicle, and an emergency lane change is possible. It can be dealt with by a quick turn when required.

The vehicle attitude control device of the present invention can achieve the following effects.

1) The above-mentioned correction of the behavior amount is not performed by changing the direction of the wheels by the auxiliary steering mechanism as in the conventional case, but the behavior amount generated in the vehicle body by the drive difference between the left and right driven wheels is used. , Only the amount of movement can be increased or decreased without affecting the lateral speed. Therefore, there is no fear of giving a new discomfort to the driver by the control as in the conventional case.

2) Furthermore, since the means for applying the moment is the motor, the safety is high when the control system fails. That is, in general, the electronic control unit of the vehicle is
It is usually used in a bad environment such as noise, and it is extremely difficult to eliminate malfunctions. This device is roughly classified into two modes, that is, a case where an excessive control amount is commanded and a case where it is not controlled. More important to the vehicle is the former case. In the conventional system using the auxiliary steering mechanism, in the case of a failure in this mode, the wheels remain steered in the wrong direction, which may lead to a fatal accident. In the device of the present invention, by setting the motor control device so as to be destroyed when an excessive control amount is commanded, even if an excessive control amount is commanded, power is cut off due to destruction of the motor control device. So, although the ability to change posture is lost, there is no danger of losing control.

3) In the conventional method of correcting the behavior amount by providing a difference in the number of rotations of the left and right motors of the driving wheels in a motor-driven vehicle, a difference in the number of rotations is generated when the vehicle is traveling even if the driving force is raised to the limit. There is no room. In the present invention, a driving force difference is provided to a wheel (driven wheel) different from the wheel that propels the vehicle to correct the behavior amount. Therefore, even if the driving force of the propulsion wheels reaches the limit of gripping the road surface, the moment for attitude control can be added regardless of this. In particular, on a road with a low slip limit driving force such as an icy road, it is possible to increase the total propulsive force by applying driving torque to both the left and right driven wheels. You can also expect stability. 4) In the present invention, since the motor is provided on the driven wheels other than the drive wheels of the main prime mover of the vehicle, the motor is activated in an emergency such as when the main prime mover breaks down at a railroad crossing or an intersection. It is possible to avoid the danger of escape.

〔Example〕

First Embodiment A vehicle attitude control system according to a first embodiment of the present invention will be described with reference to FIGS. 5 and 6.

The vehicle attitude control device according to the present embodiment is applied to an auxiliary steering device for a vehicle having a main steering device, and is an example of a type in which left and right motors are commanded to have torques of equal magnitude and opposite directions.

As shown in FIG. 5, the device of the present embodiment has a steering angle sensor 1
The vehicle speed sensor 2, the behavior sensor 3, the target behavioral amount calculation means 10, the control amount calculation means 20, the drive means 30, the first motor 41, and the second motor 42.

The steering angle sensor 1 measures the steering angle of the steering wheel 5 of the vehicle 4, is composed of a magnetic encoder, and is mounted coaxially with the steering wheel 5.

The vehicle speed sensor 2 detects the speed of the vehicle 4, is composed of a tacho generator, and is incorporated in a transmission (not shown).

The behavior sensor 3 detects a yaw rate as a behavior amount of the vehicle 4, and includes a yaw rate sensor 7 formed of a rate gyro, and is incorporated on the floor in the vehicle compartment.

The target behavioral amount calculation means 10 is composed of a target yaw rate calculation circuit 11 and calculates a target yaw rate from the steering angle signal output from the steering angle sensor 1 and the vehicle speed signal output from the vehicle speed sensor 2.

The control amount calculation means 20 includes a deviation calculation means 21, a correction amount calculation means 22, and a motor command value calculation means 23.

The deviation calculation means 21 comprises a subtraction circuit 211 for calculating the deviation between the target yaw rate signal output from the target yaw rate calculation means 11 and the detected yaw rate signal output from the yaw rate sensor 7.

The correction calculation means 22 is composed of a moment calculation circuit 221 that calculates an additional moment necessary to make the yaw rate deviation zero based on the yaw rate deviation signal output from the subtraction circuit 211.

The motor command value calculation means 23 is the moment calculation circuit 22.
A torque calculation circuit 23 that calculates the driving torque or braking torque that each of the left and right motors should exert from the magnitude and sign (significance) of the correction signal (moment command value) output from 1
1 and 233 and current calculation circuits 232 and 234 that calculate the current necessary to generate this torque according to the type of motor, and calculate the control amount necessary to correct and control the vehicle attitude. .

The drive unit 30 includes a first motor control device (left) 31, a second motor control device (right) 32, and a power supply source 33.

The first motor control device 31 includes a power supply source 33 and a first motor.
A first chopper 312 that is connected to 41 and adjusts the power of the electric power supplied to the motor, and outputs a signal that controls the first chopper 312 based on the voltage or current value commanded to the first motor 41. And a first voltage / current control circuit 311 that

The second motor control device 32 includes a power supply source 33 and a second motor.
A second chopper 322 that is connected to 42 and adjusts the power of the electric power supplied to the motor, and outputs a signal that controls the second chopper 322 based on the voltage or current value instructed to the second motor 42. And a second voltage / current control circuit 321.

The power supply source 33 is a battery that is connected to the first motor control device 31 and the second motor control device 32 and supplies electric power to the motor.

The first motor 41 is connected to the left driven wheel 51 and continuously variably controls the torque of each shaft of the driven wheel based on the electric power controlled by the driving means 30.

The second motor 42 is connected to the right driven wheel 52 and continuously variably controls the torque of each shaft of the driven wheel based on the electric power controlled by the driving means 30.

The target yaw rate calculation circuit 11, the subtraction circuit 211, the moment calculation circuit 22, and the motor command value calculation circuit 23 composed of the torque calculation circuits 231, 233 and the current calculation circuits 232, 234 perform calculation processing by a microcomputer. .

The function performed by this arithmetic processing will be described in detail with reference to FIG.

First, from the steering angle sensor 1, the value of the steering angle δ _f as the pulse count value of the magnetic encoder, and from the vehicle speed sensor 2, the value of the vehicle speed u as the actual value of the vehicle speed obtained by converting the output of the tacho generator into a digital value, From the yaw rate sensor, the value of the yaw rate ω is read as the actual value of the yaw rate obtained by converting the output of the rate gyro into a digital value (P1).

Next, the target yaw rate ω ^* is calculated by the following formula (P
2).

ω ^* = K ₁ δ _f (1) Here, K ₁ is a proportional constant that changes with respect to the vehicle speed u as K ₁ = β ₁ / (α ₁ u + 1) (2) Is. α ₁ and β ₁ are appropriate constants.

Next, the program corresponding to the subtraction circuit 211 executes the following calculation (P3).

Δω = ω ^* −ω (3) Next, the required moment m is calculated from the yaw rate deviation Δω.
Calculate according to the following formula (P4).

_{m (k) = a 0 ·} Δω (k) + a 1 · Δω (k-1) + m (k-1) ··· (4) where, k represents a time point of control. The above equation corresponds to the PI (proportional / integral) control equation of the continuous value control system. a ₀
Is the proportional gain and a ₁ is the integral gain. These gains are selected to be large within the limit that the system becomes unstable due to the error of the measurement value.

Next, the command torques T _R and T _L of the left and right motors are calculated according to the following equation (P5).

T _R =-(m / t) · (r / λ) T _L = -T _R (5) t is the distance between the wheels with the motor (tread),
r is the radius of the wheel, and λ is the reduction ratio from the motor to the wheel. Standing at the center of gravity of the vehicle and taking the clockwise moment positive, T _R is the braking torque, and T _L is the driving torque.

Next, the motor current command values i _R ^* and i _L ^* are obtained according to the following equation (P6).

i _R ^* = T _R / K _t i _L ^* = T _L / K _t (6) K _t is the torque constant of the motor.

Next, based on the preset limit formula (maximum limit),
Determine the output values of i _R ^* and i _L ^* obtained in P6 (P7, P8, P
9).

The relationship between the above program and each circuit of FIG. 5 is as follows:
It looks like this:

・ Target yaw rate calculation circuit 11 → P1, P2 ・ Subtraction circuit 211 → P3 ・ Moment calculation circuit 221 → P4 ・ Torque calculation circuit 231, 233 → P5 ・ Current calculation circuit 232, 234 → P6, P7, P8, P9 Next, The voltage / current control circuits 311 and 321 use normal current control type pulse width modulation (PWM) circuits. A deviation signal between the values of i _R ^* , i _L ^* and the motor currents i _R , i _L detected by a sensor (not shown) is created, and this signal and the triangular wave carrier are compared, depending on the magnitude relationship between the two. The choppers 312 and 322 are driven by the generated pulses, and the current of each motor is controlled so as to follow the command value.

The operation and effect of this embodiment having the above configuration are as follows.

First, the steering angle δ _f and the output of the tacho generator are converted into digital values as the count values of the pulses of the magnetic encoder, which are the outputs of the steering angle sensor 1 for measuring the steering wheel angle of the vehicle and the vehicle speed sensor 2 for measuring the vehicle speed. The vehicle speed u as the actual value of the vehicle speed is input to the target behavioral amount calculation means 10. Further, the value of the yaw rate ω as the actual value of the yaw rate obtained by converting the output of the rate gyro into a digital value, which is the output of the yaw rate sensor 7 for detecting the yaw rate as the behavior amount of the vehicle 4, is input to the deviation calculating means 21. It

Next, in the target behavioral amount calculation means 10, the steering angle signal δ _f
The target yaw rate ω ^{* is} calculated from the vehicle speed signal u and the vehicle speed signal u, and the target yaw rate ω ^* is output to the subtraction circuit 211 of the control amount calculation means 20.

Next, in the control amount calculation means 20, first, the subtraction circuit 211 of the deviation calculation means 21 performs a deviation calculation of the target yaw rate signal ω ^* and the detected yaw rate signal ω to obtain the yaw rate deviation signal Δω to the correction calculation means 22. Output. Next, the moment calculation circuit 221 of the correction calculation means 22 outputs to the motor command value calculation means 23 the additional moment m (k) calculated to make the yaw rate deviation zero based on the yaw rate deviation signal Δω. Further, a motor command value calculation means
In 23, the torque calculation circuits 231 and 233 output the command torques T _R and T _L calculated based on the moment command value m (k), and the current calculation circuits 232 and 234 output the command torque T _R ,
The motor current command values i _R ^* , i _L ^* calculated from T _L
Output to 42.

Further, in the motor control devices 31, 32 of the driving means 30, the choppers 312, 3 are controlled by the voltage / current control circuits 311, 321 based on the motor current command values i _R ^* , i _L ^* output to the motors 41, 42.
22 is controlled and the power of the electric power supplied to the motor is adjusted.

Next, the motors 41 and 42 continuously variably control the torque of each shaft of the driven wheels based on the electric power controlled by the drive means 30, thereby controlling the attitude of the vehicle.

As a result, if the driver steers by δ _f under a certain vehicle speed u, the yaw rate ω ^* desired by the driver at that time is determined by the formulas (1) and (2) as a target value for control. If the vehicle is traveling with a yaw rate of ω ^* , Δω in the equation (3) is zero, and control is not performed. If the actual vehicle yaw rate ω does not match ω ^* due to disturbances or other causes, the excess / deficiency Δω
Is calculated for each control cycle by the formula (3), and the moment m required to make Δω zero is determined by the formula (4). Furthermore, the torque required for the motor to generate m is obtained as the torque having the same magnitude and the opposite direction by the equation (5), and the required value of the current is determined by the equation (6), and the torque is passed through the PWM circuit. Ordered to the chopper.
As a result, the left and right motors generate a predetermined torque,
Bring the vehicle yaw rate closer to the desired value.

As a result, in the vehicle equipped with the device of the present embodiment, since the torque of the motor is equal in magnitude to the driving torque and the braking torque, only the yaw rate is affected without affecting the lateral motion of the vehicle and the motion in the traveling direction. Can be controlled independently.

Further, the motor generating the braking torque operates as a generator, and converts the kinetic energy of the vehicle into electric energy. This energy returns to the input side (battery side) of the braking side chopper, but since the braking side chopper and the driving side chopper are connected at the input side, the energy recovered from the braking side is directly passed through the driving side chopper. It is supplied to the drive motor. Therefore, even when a large moment is generated, it is sufficient to supply only the energy for the loss of both motors from the battery, so that the battery having a small capacity is required.

Second Embodiment A vehicle attitude control device according to a second embodiment of the present invention will be described in detail with reference to FIGS. 7 to 9 focusing on differences from the first embodiment.

The vehicle attitude control device of the present embodiment is applied to an auxiliary steering device of a vehicle having a main steering device, and is an example of a type in which left and right motors are commanded to drive side torques having different magnitudes.

As shown in FIG. 7, the device of the present embodiment has a steering angle sensor 1
A vehicle speed sensor 2, a behavior sensor 3, a throttle angle sensor 7, an engine rotation sensor 8, a target behavioral amount calculating means 10, a control amount calculating means 20, a driving means 30, and a first motor 41. , The second motor 42 and the road surface friction coefficient determination device 70
Consists of.

The steering angle sensor 1, the vehicle speed sensor 2, and the behavior sensor 3 are the first
The configuration is similar to that of the embodiment.

The throttle angle sensor 7 detects the throttle angle of the engine, is composed of a potentiometer, and is incorporated in the carburetor.

The engine rotation sensor 8 detects the number of rotations of the engine, is composed of a magnetic encoder, and is incorporated in the flywheel.

Both the target behavior calculating means 10 are constructed in the same manner as in the first embodiment.

The road surface friction coefficient determining means 70 is a device that determines the friction coefficient of the road surface, and is configured by a device that determines the friction coefficient based on reflection of laser light or the like, or a manual switch device that is operated by a driver. The road surface friction coefficient determining means 70
The road surface friction coefficient signal output from is input to three changeover switch means 224, 239, 240 provided in the control calculation means 20, the changeover switch means, based on the input signal,
The contact is switched to the contact H or the contact L depending on whether the friction is high (high μ) or low (low μ).

The control amount calculation means 20 includes a deviation calculation means 21, a correction amount calculation means 22, and a motor command value calculation means 23.

The deviation calculation means 21 comprises a subtraction circuit 211 for calculating the deviation between the target yaw rate signal output from the target yaw rate calculation means 11 and the detected yaw rate signal output from the yaw rate sensor 7.

The correction amount calculation means 22 is based on the yaw rate deviation signal output from the subtraction circuit 211, and calculates the additional moment required to make the yaw rate deviation zero. Circuit 2
23, and the common contact C is connected to the subtraction circuit 211, the contact H is connected to the first moment calculation circuit 222, and the contact L is connected to the second moment calculation circuit 223. Then, the first changeover switch means 224 switches to the contact point H or L based on the road surface friction coefficient signal output from the road surface friction coefficient determination means 70. In the case of H, the yaw rate deviation signal is calculated as the first moment calculation. Circuit 222
In the case of L, the yaw rate deviation signal is transmitted to the second moment calculation circuit 223, and the yaw rate deviation signal output from the subtraction circuit 211 is transmitted.

The motor command value calculation means 23 includes first torque calculation means 235a, 235b and second torque calculation means 237a, 237b corresponding to the left and right driven wheels 51, 52, respectively, and a first current calculation circuit.
236, a second current calculation circuit 238, and a second changeover switch means
239, third changeover switch means 240, and first adder 241
A second adder 242 and an engine torque estimation circuit 243.
And a propulsion motor torque calculation circuit 244, and the driving torque or braking torque to be exerted by each of the left and right motors from the magnitude and sign (significance) of the correction signal (moment command value) output from the correction amount calculation means 22. Is calculated to calculate the control amount necessary for correcting and controlling the vehicle attitude.

In the second changeover switch means 239, the contact H is the output terminal of 235a of the first torque calculation means, and the contact L is the first adder 241.
The common contact C is connected to the output terminal of the first current calculation circuit 236.

In the third changeover switch means 240, the contact H is the output terminal of 235b of the first torque calculation means, and the contact L is the second adder 242.
, And the common contact C is connected to the input terminal of the second current calculation circuit 238, respectively.

The correction signal (moment command value) output from the correction calculation means 22 is transferred to the contact H of the first changeover switch means 224.
If connected to the first torque calculation circuit 235a, 235b
Further, when the first changeover switch means 224 is connected to the contact L, it is configured to be inputted to the second torque calculation circuits 237a and 237b, respectively, and the drive that the left and right motors 41 and 42 should exhibit. Calculate the torque.

Then, the control torque signal output from the first torque calculation circuit 235a is transmitted to the second changeover switch means 239 and further input to the first current calculation circuit 236.
The control torque signal output from the first torque calculation circuit 235b is transmitted to the third changeover switch means 240 and further input to the second current calculation circuit 238.

The engine torque estimation circuit 243 uses the throttle angle sensor 7
The throttle angle signal input from the engine speed sensor and the engine speed signal input from the engine speed sensor 8
The engine torque T _e is estimated based on the engine power performance curve shown in the figure, and an engine torque estimation signal is output.

The propulsion motor torque signal calculation circuit 244, based on the engine torque estimation signal output from the engine torque estimation circuit 243, outputs the propulsion motor torque command signal according to the following equation to the first adder 241 and the second adder. Output to 242.

T _p = K ₂ · T _e λ _e / λ (7) where λ _e is the reduction ratio from the engine to the wheels, λ is the reduction ratio from the motor to the wheels, and the constant K ₂ is 0 to 1.0. It can be arbitrarily determined within the range.

The control torque signal output from the second torque calculation circuit 237a is added to the motor torque command value T _p output from the propulsion motor torque calculation circuit 244 in the first adder 241, and the second changeover switch means is provided. It is output to the terminal L of 239.

The control torque signal output from the second torque calculation circuit 237 is added to the motor torque command value T _p output from the propulsion motor torque calculation circuit 244 by the second adder 242, and the third switching is performed. It is output to the terminal L of the switch means 240.

The drive unit 30 includes a first motor control device (left) 31, a second motor control device (right) 32, and a power supply source 33.

The first motor control device 31 includes a power supply source 33 and a first motor.
41 to output a signal for controlling the first chopper 312 based on the current value instructed by the first chopper 312 for adjusting the power of the electric power supplied to the motor and the first current calculation circuit 236. And a first voltage / current control circuit 311 that

The second motor control device 32 includes a power supply source 33 and a second motor.
A second chopper 322 that is connected to 42 and adjusts the power of the electric power supplied to the motor, and outputs a signal that controls the second chopper 322 based on the current value commanded by the second current calculation circuit 238. And a second voltage / current control circuit 321.

The power supply source 33 is a battery that is connected to the first motor control device 31 and the second motor control device 32 and supplies electric power to the motor.

The first motor 41 is connected to the left driven wheel 51 and continuously variably controls the torque of the shaft of the driven wheel based on the electric power controlled by the driving means 30.

The second motor 42 is connected to the right driven wheel 52 and continuously variably controls the torque of the shaft of the driven wheel based on the electric power controlled by the driving means 30.

The target yaw rate calculation circuit 11, the subtraction circuit 211, the first moment calculation circuit 222 and the second moment calculation circuit 223, the first torque calculation circuits 235a and 235b and the second torque calculation circuits 237a and 237b, and the first Current calculation circuit 23
6. A motor command value calculation circuit 23 including a second current calculation circuit 238, a first adder 241, and a second adder 242.
Is performed by arithmetic processing by a microcomputer.

The function performed by this arithmetic processing will be described in detail with reference to FIG.

Here, the calculation processing by the microcomputer corresponding to the first moment calculation circuit 222, the first torque calculation circuits 235a and 235b, the first current calculation circuit 236, and the second current calculation circuit 238 is the first embodiment. And (1) in FIG.
Since it is the same as the expression (6), the description thereof will be omitted. In addition,
P1, P2, P3, P4, P5, P6, P7, P8, P9 in the first embodiment
Correspond to P11, P12, P13, P19 and P21, P22 and P23, P24, P25 and P26 in the second embodiment and FIG. 9, respectively.

Next, in the second moment calculation circuit 223, the required moment m ′ at low μ is calculated by the equation (4) ′ similar to the equation (4).
Is calculated.

m ′ (k) = a _o ′ · Δω (k) + a ₁ ′ · Δω (k−1) + m ′ (k−1) (4) ′ where the gains a ₀ ′ and a ₁ ′ are Set smaller than a ₀ and a _{1 in} equation (4).

Next, the second torque calculation circuits 237a and 237b calculate the torques T ″ _R and T ″ _L for generating moments of the left and right motors at the time of low μ by the expression (5) ′ similar to the expression (5).

Next, the first adder circuit 241, second adding circuit 242, the command torque T _'R when by adding the torque for torque and vehicle propulsion for moment generating low μ of the left and right motors by the following equation, T ′ _L
Ask for.

T ′ _R = T ″ _R + T _P T ′ _L = T ″ _L + T _P (8) Next, the engine torque estimation circuit 243 and the changeover switch 224,
The functions of 229 and 240 are also realized by a program. That is, P4
Enter the road friction coefficient μ in 1 and determine the level of μ in P15,
When it is judged to be high μ, as in the first embodiment, P21, P2
2. Execute P23 and the following P26. When it is judged to be low μ, read the throttle angle and engine speed on P16, and
The engine torque is estimated at 17, and the propulsion motor torque is calculated at P18 using equation (7), the required moment is calculated at (19) on P19, and the command torque is calculated at equations (5) 'and (8) at P20. Calculate and execute the following P23 to P26.
The flow chart of the program is also shown in FIG.

The operation and effect of this embodiment having the above configuration are as follows.

First, when running on a high μ road, the same program as in the first embodiment is executed as it is.

Next, when running on a low μ road, the program is executed in the following steps.

That is, the engine torque T _e is estimated from the throttle angle and the engine speed, and the motor torque T _P proportional to T _e is the motor torque necessary to assist the engine to propel the vehicle, and has the same value on the left and right. . On the other hand, the motor torques T ″ _R and T ″ _L necessary to correct the posture can be obtained by the equations (4) ′ (5) ′ if the yaw rate deviation Δω is known. The final required torque T _'R and T' _L is determined by the sum as (8) of the propulsion torque and moment generating torque, the left and right motor by the motor control apparatus as in the case of high μ based on this To control.

As a result, in the present embodiment, the same effect as in the first embodiment is produced on a road with a high μ.

Further, on a low μ road, the motor exerts both the torque required to correct the posture and the torque as the auxiliary propulsion force. Since the posture is corrected by the torque difference between the left and right motors, it is possible to control only the yaw rate to a desired value without affecting the lateral movement of the vehicle, as in the first embodiment. Since the direction of the vehicle can be controlled on the low μ road with a moment smaller than that on the high μ road, the gain at the time of calculating the required moment may be small. The motor further generates auxiliary propulsion torque in the same direction on the left and right to drive the rear wheels. As a result, the driving force of the vehicle is distributed to all the wheels as in the known four-wheel drive vehicle, so that stable running can be performed even on a low μ road where slipperiness occurs.

In the first and second embodiments described above, the main drive source of the vehicle is the engine, but other drive sources such as a motor can be used.

Further, in the above-mentioned embodiment, the power supply source for the attitude control is the battery, but the present invention is not limited to this, and other means can be used. For example, the output can be adjusted by using the engine generator. It is possible.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing the concept of the present invention, FIGS. 2 to 4 show a conventional technique, FIG. 2 is a schematic configuration diagram thereof, and FIG. 3 is a problem of the conventional technique shown in FIG. FIG. 4 is an explanatory diagram for explaining points, FIG. 4 is a schematic configuration diagram of another conventional technique, FIGS. 5 and 6 show a first embodiment of the present invention, and FIG. 5 is a system diagram showing the whole thereof. FIG. 6 is a flowchart of a computer program used in the first embodiment, FIGS. 7 to 9
FIG. 7 shows a second embodiment of the present invention, FIG. 7 is a system diagram showing the whole thereof, FIG. 8 is a diagram showing engine power performance used in the second embodiment, and FIG. 9 is a second embodiment. 3 is a flowchart of a computer program used. 1 ... Steering angle sensor, 2 ... Vehicle speed sensor, 3 ... Behavior sensor, 10 ... Target behavior amount calculation means, 20 ... Control amount calculation means, 21 ... Deviation calculation means, 22 ... Correction amount calculation means ,twenty three…
... motor command value computing means, 30 ... driving means, 31 ... first motor control means, 32 ... second motor control means, 33 ... electric power supply source, 41 ... first motor, 42 ... second Second motor,
51, 52 …… Driven wheels.

Front Page Continuation (72) Inventor Taiji Otachi, Nagakute-cho, Aichi-gun, Aichi-gun, Nagaminate Yokomichi No. 41, Toyota Central Research Institute, Inc. (72) Inventor, Kazuhiko Takasu, Aichi-gun, Nagakute-machi, Aichi-gun No. 41 No. 1 Nobuo Yoshikuni, Examiner, Toyota Central Research Institute, Inc.

Claims (1)

[Claims] 1. A posture control device for controlling a posture of a vehicle by providing an auxiliary steering device separately from a main steering device of the vehicle, wherein a steering angle sensor for detecting a steering angle of a steering wheel and a speed of the vehicle are detected. A vehicle speed sensor, a behavior sensor that detects the amount of movement of the vehicle, and a steering angle signal output from the steering angle sensor and a vehicle speed signal output from the vehicle speed sensor are used in consideration of the disturbance or the vehicle state acting on the vehicle. Target behavior amount calculating means for calculating a target behavior amount, and deviation calculating means for calculating a deviation between the target behavior amount signal output from the target behavior amount calculating means and the detected behavior amount signal output from the behavior sensor. A correction amount calculating means for calculating a correction amount equivalent to the behavior amount deviation based on the behavior amount deviation signal output from the deviation calculating means; and a vehicle based on the correction amount signal output from the correction amount calculating means. Driving force or braking force required to correct and control both postures,
Alternatively, a motor command value calculating means for calculating a control amount commensurate with the driving force and the braking force, a control amount calculating means comprising: and an electric power supplied to the motor based on a motor command signal output from the control amount calculating means. A drive unit comprising a first motor control device and a second motor control device, and a power supply source connected to the first motor control device and the second motor control device to supply electric power to the motor; Based on the controlled electric power, the power of the propulsion motor of the vehicle is not directly transmitted, the first motor for continuously variably controlling the torque of the shaft of the left driven wheel of the driven wheels, and the electric power controlled by the drive means. Based on this, a second motor that continuously variably controls the torque of the right driven wheel shaft of the driven wheel to which the power of the vehicle propulsion prime mover is not directly transmitted, and controls the vehicle attitude in the desired direction. Attitude control device for a vehicle is characterized in that no in earthenware pots.