JPH01111538A - Vehicle attitude controller - Google Patents

Abstract

PURPOSE:To expand the controllable range of vehicle attitude by calculating a desired behavior amount as the one desired by a driver from detected values of steering angle and vehicle speed and generating a controlling force according to the deviation of behavior amount of actual yaw rate or the like from the desired behavior amount. CONSTITUTION:In an auxiliary travelling device provided separately from a main one, a desired behavior amount is calculated 10 from the outputs of a steering angle sensor 1 and vehicle speed sensor 2 in the consideration of the external turbulence acting on the vehicle or vehicle condition while the deviation of behavior amount detected by a behavior sensor 3 from the desired one is calculated 21. Also, an equivalent correction amount is calculated 22 on the basis of the behavior amount deviation and a controlling amount corresponding to a drive force and/or braking force necessary for correcting controllably the vehicle attitude on the basis of said correction amount is calculated 23. This controlling amount is used as a motor commanding signal so that first and second motors 41, 42 are driven through respective motor controlling devices 31, 32 to control the shaft torque of left and right driven wheels and the vehicle position in the desired direction.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vehicle attitude control device, and more specifically,
The present invention relates to a vehicle attitude control device that includes an auxiliary steering surface separate from the vehicle's main steering device and controls the vehicle attitude in a desired direction.

[Conventional technology and its problems]

Conventionally, one of the vehicle attitude control devices is a four-wheel steering vehicle ("A study of an adaptive Sayo angular velocity steering system for electronically controlled rear wheel actual steering angle", Joint Venture, Inner Concave, etc., Vol. 7 Applied Control Symposium Proceedings, published February 1982). As shown in FIG. 2, this four-wheel steering vehicle is first provided with an auxiliary steering mechanism 61, which consists of a hydraulic cylinder 67 and a hydraulic control device 68 for controlling the cylinder 67, on the rear wheels. Next, the vehicle speed and the main steering angle of the front wheels are measured by the detectors 62 and 63, and the desired yaw rate value of the vehicle body is calculated and commanded by the circuit 4 from the fixed values on both sides. 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 instructs the control device 68 of the auxiliary steering mechanism 61 to calculate the auxiliary steering angle. This causes the hydraulic cylinder 67 to operate and change the direction of the rear wheels. With the above configuration, in this four-wheel steering vehicle, when the vehicle body moves in a direction different from the direction intended by the driver due to crosswind disturbance, for example, the auxiliary steering mechanism 61 is activated to change the attitude to the original direction. They believe they can get back on track.

However, in this four-wheel steering vehicle, when the vehicle is running, a crosswind is applied to the vicinity of the front wheels as shown in FIG. 3 (arrow A). When the rear wheels are steered clockwise to counteract the clockwise moment caused by this crosswind (arrow B), a side force is generated in the direction of arrow C in the figure, which suppresses the yaw rate caused by the crosswind. At the same time, a new lateral force in the vertical direction in the figure is generated due to the side force. For this reason,
Although the rotation of the vehicle body is suppressed, parallel movement in the lateral direction is accelerated, giving the driver a sense of anxiety. Furthermore, if the auxiliary steering mechanism malfunctions and stops moving, there is a high possibility that the rear wheels will become fixed in a certain direction, which is dangerous.

Another example of the above-mentioned prior art is an "omnidirectional movable trolley" (Japanese Unexamined Patent Publication No. 146757/1983). As shown in FIG. 3, this omnidirectional movable trolley is first equipped with a motor M1 on each of its four wheels so that it can be freely steered.

Next, a motor M2 is provided for each of the left and right drive wheels to drive the vehicle. A control target value calculation circuit 70 reads the position of the joystick 71 and instructs the direction and speed in which the vehicle should travel. A rotation angle calculation circuit 72 calculates and commands the rotation angle of the motor M1 based on the command value of the running direction. Based on this command value, the arithmetic circuit 73 calculates the required value of the motor current and issues the command to the four motor control devices 74. On the other hand, the rotation speed calculation circuit 75 for the left and right motors calculates the rotation speed of the motor M2 based on the travel speed command value and issues a command. Further, the arithmetic circuit 76 calculates the corrected rotational speed of the left and right drive wheels necessary to make the value of the yaw rate detected by the gyro 77 zero. The adder 78 adds the output signals of the arithmetic circuits 75 and 76, and outputs the result as the final rotational speed of the left and right motors M2 to the two motor control devices 80 via the motor voltage command value arithmetic circuit 7.9. command.

The operation of the control device for this mobile cart will be explained as follows. That is, when there is no disturbance, the left and right rotational speeds of the motor M2 are equal, so the motor moves straight in the direction determined by the motor M1 at a desired speed (yaw rate is zero). Here, if the direction of the vehicle deviates from the desired direction due to an uneven 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 determined direction. As a result, this movable trolley tries to restore its posture by creating a difference in the rotation speed between the left and right drive motors, which eliminates the extra lateral force generated by control like the four-wheel steering vehicle mentioned earlier as a conventional technology. There are no drawbacks.

However, since this mobile cart uses a mechanism in which direction correction is also performed using the driving wheels, a new drawback occurs in that the driving force control system and the attitude control system interfere with each other, resulting in a narrow controllable range. For example, when a vehicle is required to travel at maximum speed, the driving force of the drive wheels is naturally increased to the maximum grip of the road surface. In this state, if you try to add additional driving force to correct the direction, the wheels will exceed their grip limit and you will be unable to control the vehicle. Therefore, there has been a problem in that as the traveling speed of the vehicle increases, the range in which attitude control can be performed becomes narrower.

Therefore, the present inventors conducted intensive research to solve the problems of the prior art as described above, and as a result of conducting various systematic experiments, they came up with the present invention.

[Purpose of the invention]

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

The present inventors focused on the following points regarding the above-mentioned problems of the prior art. That is, the driver attempts to control the vehicle into a desired attitude by steering.

Therefore, the steering angle is considered to be proportional to the amount of behavior desired by the driver, such as the yaw rate of the vehicle. However, the proportionality constant depends on the vehicle speed. Generally, the responsiveness of behavioral quantities such as yaw rate to the steering angle is sharp when driving at high speeds, and slow when driving at low speeds.

Therefore, as the vehicle speed increases, the proportionality constant should be made smaller, and the target behavior amount should be set smaller for the same steering angle. Based on the above, two quantities, steering angle and vehicle speed, are detected, the target behavior quantity is calculated as the behavior quantity desired by the driver, and outputted as a target value for control, and a behavior quantity detection sensor such as a gyro is used. A control force is generated according to the deviation between the measured behavior quantity such as the actual yaw rate and the target value, and a driving force difference is generated in the motors installed on each of the left and right non-driving wheels of the vehicle, and the control force is applied to the vehicle body. We focused on solving the main problems of the prior art by adding a moment to control the attitude of the vehicle in a desired direction.

[Description of the invention]

As shown in FIG. 1, the vehicle attitude control device of the present invention has the following features:
A steering angle sensor detects a steering angle of a steering wheel in an attitude control device that controls the attitude of a vehicle by providing an auxiliary steering device separate from a main steering device of the vehicle.

1, a vehicle speed sensor 2 that detects the speed of the vehicle, a behavior sensor 3 that detects the amount of behavior of the vehicle, a steering angle signal output from the steering angle sensor 1, and a vehicle speed signal output from the vehicle speed sensor 2. a target behavior amount calculation means 10 that calculates an optimal target behavior amount in consideration of the disturbance acting on the vehicle or the vehicle state; and a target behavior amount signal output from the target behavior amount calculation means 10 and the output from the behavior sensor 3. a deviation calculation means 21 that calculates the deviation from the detected behavior amount signal, and a correction amount calculation that calculates a correction amount equivalent to the behavior amount deviation based on the behavior amount deviation signal output from the deviation calculation means 2. means 22, and motor command value calculation means 23 for calculating a control amount corresponding to the driving force and/or braking force necessary for correcting and controlling the vehicle attitude based on the correction amount signal output from the correction amount calculation means 22. , a system consisting of? III calculation means 20, a first motor control device 31 and a second motor control device 32 that adjust the electric power supplied to the motor based on the motor command signal that is the output of the control amount calculation means 20, and the first motor A driving means 30 comprising a power supply source 33 connected to a control device 31 and a second motor control device 32 to supply power to the motor, and a disturbance acting on the vehicle or the vehicle state based on the power controlled by the driving means 30. In order to generate a control force according to the deviation of the detected behavior amount from the target behavior amount considering the It consists of a motor 41 and a second motor 42, and is characterized in that it controls the attitude of the vehicle in a desired direction.

The functions and effects of the present invention having the above configuration are as follows. That is, the present invention provides an attitude control device that controls the attitude of the vehicle by providing an auxiliary steering device separate from the main steering device of the vehicle. First, the steering angle sensor 1 detects the steering angle at the steering wheel. , and converts it into an electrical signal that corresponds to the steering angle.

Further, the vehicle speed sensor 2 detects the vehicle speed and converts it into an electrical signal corresponding to the vehicle speed. Further, the behavior sensor 3 detects the amount of change in vehicle behavior such as yaw rate and lateral speed, and converts it into an electrical signal or the like corresponding to the amount of change in behavior.

Then, the steering angle signal outputted from the steering angle sensor 1 and the vehicle speed signal outputted from the vehicle speed sensor 2 are used in the target behavior amount calculation means 10 to determine the optimum target behavior in consideration of the disturbance acting on the vehicle or the vehicle state. Calculates the amount and outputs it as a target value for control.

In the control amount calculation means 20, first, the deviation calculation means 21 calculates the deviation between the target behavior type signal outputted from the target behavior amount calculation means 10 and the detected behavior amount signal outputted from the behavior sensor 3. do. Next, the correction amount calculation means 22 calculates a correction amount equivalent to the behavior amount deviation based on the behavior amount deviation signal outputted from the deviation calculation means 21. Next, the motor command value calculation means 23 calculates a control amount corresponding to the driving force and/or braking force necessary to correct and control the vehicle attitude based on the correction amount signal output from the correction amount calculation means 22, A motor command signal is output as the output of the control amount calculation control means 20.

Based on the motor command signal that is the output of the control amount calculation control means 20, the drive means 30 adjusts the electric power supplied to the motor using the first motor control value 231 and the second motor control device 32. The first motor 41 and the second motor 42 apply a control force to the driven wheels to which the power of the vehicle propulsion prime mover is not directly transmitted, in accordance with 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. First motor 41 to give
and drives the second motor 42.

Note that 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 power to the motor.

Therefore, depending on the magnitude of the behavior amount calculated by the target behavior amount calculation means 10 and the behavior amount detected by the behavior sensor 3, the following effects occur.

i) When the behavior amount calculated by the target behavior amount calculation means 10 and the behavior amount detected by the behavior sensor 3 match, the output of the control amount calculation means 20 becomes zero, and the motor 41.42 of the driven wheel 51.52 does not generate torque.

11) If the behavior amount detected by the behavior sensor 3 is larger than the behavior amount calculated by the target behavior amount calculation means 10, a negative signal is generated at the output of the deviation calculation means 21, and this signal causes the correction amount calculation means to 22 calculates the moment necessary to suppress the amount of behavior of the vehicle. This moment is proportional to the torque difference between the two motors 41,42. The motor command value calculating means 23 first determines the torque to be shared by the two motors 41, 42 in order to create this torque difference. For example, normally, the driving torque and braking torque of the torque difference A are commanded, but both may be the driving torque or the braking torque. Next, the voltage or current of the two motors 41 and 42 necessary to generate this command torque is calculated depending on the type of motor used. Based on this specified value, a predetermined torque is exerted by the action of power regulators such as voltage and current control circuits, choppers, and inverters used in normal motor control, thereby adding a moment to the vehicle and suppressing the amount of movement. By doing this, you can get closer to the desired amount of behavior.

iii) If the behavior amount detected by the behavior sensor 3 is smaller than the behavior amount calculated by the target behavior amount calculation means 10,
A positive signal is generated at the output of the deviation calculating means 21, and based on this signal, the correction amount calculating means 22 calculates the moment necessary to increase the amount of behavior of the vehicle. This moment is generated by the two motors 41.4 as in case ii) above.
This moment is added to the vehicle by the torque difference between the two and the amount of behavior is increased to bring it closer to the desired amount of behavior.

As described above, when a disturbance such as a crosswind causes the vehicle to exhibit a larger amount of behavior than the driver desires, the newly added moment by the two motors suppresses the amount of behavior, and the disturbance caused by the disturbance It is possible to restore the posture of the vehicle to its original orientation.

Conversely, when the responsiveness of the vehicle's posture change to the driver's steering worsens, such as when the vehicle's loaded weight becomes large, the moment added by the motor increases the amount of behavior, so the driver's responsiveness becomes You can drive with the same steering feel as normal without experiencing any deterioration.

Furthermore, if the target behavior amount is set to exceed the amount of behavior that should be obtained by steering the main steering system, the auxiliary moment of the motor will provide turning performance that exceeds the vehicle's original characteristics, making it possible to avoid emergency lane changes. Able to quickly change direction when required.

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

I) The correction of the amount of behavior described above is not done by changing the direction of the wheels using an auxiliary steering mechanism as in the past, but instead uses the amount of behavior generated in the vehicle body due to the drive difference between the left and right driven wheels. , only the amount of behavior can be increased or decreased without affecting the lateral velocity.

Therefore, there is no risk of giving the driver a new sense of discomfort due to control as in the conventional case.

2) Furthermore, since the means for applying the moment is a motor, safety is high in the event of a failure in the control system. That is, vehicle electronic control devices are generally used in adverse environments such as high and low temperatures, vibrations, and noise, and it is extremely difficult to completely eliminate malfunctions. The failure modes of this device can be roughly divided into two: cases in which an excessive control amount is commanded, and cases in which control is not performed. The former case is more important for vehicles. In systems using conventional auxiliary steering mechanisms, a failure in this mode would leave the wheels steered in the wrong direction, potentially leading to a fatal accident. In the device of the present invention, the motor control device is set to be destroyed when an excessive control amount is commanded, so that even if an excessive control amount is commanded, the power is cut off due to the destruction of the motor control device. Therefore, although the ability to change its attitude will be lost, there is no risk of it becoming uncontrollable.

3) In the conventional method of correcting the amount of behavior by setting a rotation speed difference between the left and right motors of the drive wheels in a motor-driven vehicle, even if the driving force is increased to near the limit, a rotation speed difference will still occur if the vehicle is running. There's no room. In the present invention, the amount of behavior is corrected by providing a driving force difference between wheels (driven wheels) different from the wheels that propel the vehicle. Therefore, even if the driving force of the propulsion wheels has reached the limit capable of gripping the road surface, a moment for attitude control can be added regardless of this. Particularly on roads with low slip limit driving force, such as frozen roads, the total propulsive force can be increased by applying drive-side torque to both the left and right driven wheels, similar to what is called a four-wheel drive vehicle. You can also expect driving stability. 4) In the present invention, since the motor is provided on the driven wheels that are separate from the driving wheels of the main motor of the vehicle,
In the event of an emergency situation, such as when the main motor malfunctions and stops at a railroad crossing or intersection, the motor can be activated to escape and avoid danger.

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

The vehicle attitude 11 control device of this 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 torques of equal magnitude and opposite direction are commanded to the left and right motors. .

As shown in FIG. 5, the device of this embodiment includes a steering angle sensor 1
, vehicle speed sensor 2 , behavior sensor 3 , target behavior type calculation means 10 , control amount calculation means 20 , drive means 30 ,
It consists of a first motor 41 and a 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 into a transmission (not shown).

The behavior sensor 3 detects the yaw rate as a behavior amount of the vehicle 4, and includes a yaw rate sensor 7 configured with a rate gyro, and is installed on the floor of the vehicle interior.

The target behavior amount calculation means 10 includes a target yaw rate calculation circuit 1
1, the target yaw rate is calculated 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 includes the target yaw rate calculation means 11.
The subtraction circuit 211 calculates the difference between the target yaw rate signal output from the yaw rate sensor 7 and the detected yaw rate signal output from the yaw rate sensor 7.

The correction calculation means 22 includes a moment calculation circuit 221 that calculates the 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 performs a torque calculation to calculate the driving torque or braking torque to be exerted by each of the left and right motors from the magnitude and sign (positive or negative) of the correction signal (moment command value) output from the moment calculation circuit 221. circuits 231 and 233, and a current calculation circuit 23 that calculates the current required to generate this torque according to the type of motor.
2.234, and calculates the control amount necessary to correct and control the vehicle attitude.

The drive means 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 first chopper 312 connected to the power supply source 33 and the first motor 41 to adjust the power of the power supplied to the motor, and a voltage commanded to the first motor 41. Alternatively, the first voltage/current control circuit 311 outputs a signal for controlling the first chopper 312 based on the current value.

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

The power supply source 33 includes a battery connected to the first motor control device 31 and the second motor control device 32 to supply 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 drive 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 drive means 30.

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

The functions performed by this arithmetic processing will be explained in detail based on FIG. 6.

First, the steering angle sensor 1 takes the value of the steering angle δ as the pulse count value of the magnetic encoder, and the vehicle speed sensor 2 takes the value of the vehicle speed U as the actual value of the vehicle speed obtained by converting the output of the tachogenerator into a digital value. The value of yaw rate ω is read from the yaw rate sensor as the actual value of the yaw rate obtained by converting the output of the rate gyro into a digital value (Pl).

Next, the target yaw rate ω1 is calculated using the following formula (P2
).

ω1= K1 δ, ... (1) Here, K, with respect to vehicle speed U, K, = β+ / (α+ u + 1)
It is a constant of proportionality that changes as shown in 12). α3
,β.

is a suitable constant.

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

Δω; ω“ −ω (3) Next, the required moment m is determined from the yaw rate deviation Δω according to the following formula (P4).

m(k) = ao・Δω(k)+aI・Δω(k−
1) 10m(k-1) (4) Here, k represents the time point of control. The above equation corresponds to an arithmetic equation for PI (proportional/integral) control of a continuous value control system.

ao is a proportional gain and a is an integral gain. These gains are selected to be large within the limit where the system becomes unstable due to causes such as errors in measured values.

Next, the command torque TR1TL for the left and right motors is determined according to the following equation (P5).

T++ = (m/l) ・ (r/λ)TL=
-TR...(5) Ren is the distance between the wheels to which the motor is attached (tread),
r is the radius of the wheel, and λ is the reduction ratio from the motor to the wheel. If we stand at the center of gravity of the vehicle and take a positive clockwise moment, then T is the braking torque and Tt is the driving torque.

Next, motor current command values iR' and i♂ are determined according to the following equations (P6).

iR”=’r*/K- it umbrella =T, /Kt ...(6) K1 is the torque constant of the motor.

Next, based on the preset limit formula (maximum limit),
Determine the output value of ijl″ and i obtained in P6 (P
7, P8, P9).

The relationship between the above program and each circuit in FIG. 5 is shown below.
It is as follows.

・Target yaw rate calculation circuit 11-4 PI, P2・Subtraction circuit 211-P3 ・Moment calculation circuit 221 →P4・Torque calculation circuit 231.233 →P5・Current calculation circuit 232.23
4 → P6, P7, P8, P9 Next, the voltage/current control circuits 311 and 321 use normal current control type pulse width modulation (PWM) circuits. i,
A deviation signal was created between the value of 1'', i♂ and the motor current 111% IL detected by a sensor (not shown), and this signal was compared with the carrier wave of the triangular wave, and generated according to the magnitude relationship between the two. The choppers 312 and 322 are driven with pulses to control the current of each motor to follow the command 1fL4.

The functions and effects of this embodiment having the above configuration are as follows.

First, the steering angle δt and the output of the tachogenerator were converted into digital values as count values of magnetic encoder pulses, which are the outputs of the steering angle sensor 1 that measures the steering wheel angle of the vehicle and the vehicle speed sensor 2 that measures the vehicle speed. The vehicle speed U is inputted to the target behavior amount calculation means 10 as the actual value of the vehicle speed. Further, the value of yaw rate ω, which is 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 that detects the yaw rate as a behavioral quantity of the vehicle 4, is input to the deviation calculation means 21. Ru.

Next, in the target behavior amount calculation means 10, the steering angle signal δ
, and the vehicle speed signal U, the target yaw rate sensor is calculated and outputted 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 calculates the difference between the target yaw rate signal ω'' and the detected yaw rate signal ω, and outputs the yaw rate deviation signal Δω to the correction calculation means 22. Output.

Next, based on the yaw rate deviation signal Δω, the moment calculation circuit 221 of the correction calculation means 22 calculates an additional moment) m(k
) is output to the motor command value calculation means 23. Furthermore, in the motor command value calculation means 23, a torque calculation circuit 231
．． 233 outputs command torques T, I, and TL calculated based on the moment command value m(k), and current calculation circuits 232 and 234 output command torques T u , T L
The motor current command value 1*"slL* calculated from is output to the motor 41.42.

Furthermore, in the motor control device 31.32 of the drive means 30, the motor current command value i output to the motor 41.42
Voltage/current control circuit 311.321 based on R', i♂
controls the choppers 312 and 322 to adjust the power of the electric power supplied to the motor.

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

As a result, if the driver steers the vehicle by δ at a certain vehicle speed U, the yaw rate ω'' desired by the driver at that time is determined as the control target value using equations (1) and (2). If the vehicle is traveling with a yaw rate of exactly ω", Δω in equation (3) is zero, and no control is performed. If the actual yaw rate ω of the vehicle does not match ω9 due to disturbance or other causes, the excess or deficiency Δω
is calculated for each control period using equation (3), and the moment m required to make Δω zero is determined using equation (4).

Furthermore, the torque of the motor required to produce m is (
Using equation 5), the torques are determined to be equal in magnitude and opposite in direction, and the required value of current is determined using equation (6), which is then commanded to the chopper via the PWM circuit. As a result, the left and right motors generate a predetermined torque, bringing the yaw rate of the vehicle closer to the desired value.

As a result, in a vehicle equipped with the device of this embodiment, since the torque of the motor is equal in driving torque and braking torque, only the yaw rate can be controlled without affecting the lateral movement of the vehicle or even the movement in the forward direction. can be controlled independently.

Additionally, the motor that generates the braking torque operates as a generator, converting the kinetic energy of the vehicle into electrical energy. This energy is transferred to the input side of the chopper on the braking side (
Returning to the battery side), since the braking-side chopper and the driving-side chopper are connected on the input side, the energy recovered from the braking-side is directly supplied to the drive motor via the driving-side chopper. Therefore, even when a large moment is generated, the battery only needs to supply energy for the loss of both motors, so a unique effect is achieved in that a small capacity battery is sufficient.

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

The vehicle attitude control device of this embodiment is applied to an auxiliary steering device of a vehicle having a main steering device, and is an example of a type that commands drive-side torques of different magnitudes to left and right motors.

As shown in FIG. 7, the device of this embodiment includes a steering angle sensor 1
, vehicle speed sensor 2 , behavior sensor 3 , throttle angle sensor 7 , engine rotation sensor 8 , target behavior amount calculation means 10 , control amount calculation means 20 , drive means 30 , and first motor 41 , a second motor 42, and a road surface friction coefficient determining device 70.

The steering angle sensor 1, the vehicle speed sensor 2, and the behavior sensor 3 are the first
The structure 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 built into the carburetor.

The engine rotation sensor 8 detects the engine rotation speed, is composed of a magnetic encoder, and is incorporated into the flywheel.

The target behavior recalculation means 10 is configured similarly to the first embodiment.

The road surface friction coefficient determination means 70 is a device that determines the friction coefficient of the road surface, and includes a device that determines the friction coefficient based on reflection of laser light or the like, and a manual switch device that is determined and operated by the driver. The road surface friction coefficient signal outputted from the road surface friction coefficient determination means 70 is transmitted to three changeover switch means 224 and 23 provided in the control calculation means 20.
9.240, and the changeover switch means switches to contact H or contact depending on whether the friction is high friction (high μ) or low friction (low μ) based on the input signal.

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 includes the target yaw rate calculation means 11.
The subtraction circuit 211 calculates the difference between the target yaw rate signal output from the yaw rate sensor 7 and the detected yaw rate signal output from the yaw rate sensor 7.

The correction amount calculation means 22 includes a first moment calculation circuit 222 and a second moment calculation circuit that calculates the additional moment necessary to make the yaw rate deviation zero based on the yaw rate deviation signal output from the subtraction circuit 211. It consists of a circuit 223 and a first changeover switch means 224 having a common contact C connected to the subtraction circuit 211, a contact H connected to the first moment calculation circuit 222, and a contact R connected to the second moment calculation circuit 223. Then, the first changeover switch means 224 switches the contact point H or L based on the road surface friction coefficient signal output from the road surface friction coefficient determination means 70, and in the case of H, the yaw rate deviation signal is used for first moment calculation. In the case of L, the yaw rate deviation signal outputted from the subtraction circuit 211 is transmitted to the circuit 222, and the yaw rate deviation signal output from the subtraction circuit 211 is transmitted to the second moment calculation circuit 223, respectively.

The motor command value calculation means 23 operates on the left and right driven wheels 51 and 52.
First torque calculation means 235a, 2 corresponding to
35b and second torque calculation means 237a, 237b
, the first current calculation circuit 236, and the second current calculation circuit 2
38, a second changeover switch means 239, a third changeover switch means 240, a first adder 241, a second adder 242, an engine torque estimation circuit 243, and a propulsion motor torque calculation circuit 244. The driving torque or braking torque to be exerted by each of the left and right motors is calculated from the magnitude and sign (positive or negative) of the correction signal (moment command value) outputted from the correction amount calculation means 22, and the vehicle attitude is corrected and controlled. Calculate the control amount necessary to do so.

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

The third changeover switch means 240 has a contact H connected to the output terminal of the first torque calculation means 235b, a contact point connected to the output terminal of the second adder 242, and a common contact C connected to the output terminal of the second current calculation circuit 238. connected to each input terminal.

The correction signal (moment command value) output from the correction calculation means 22 is transmitted to the first torque calculation circuit 235 when the first changeover switch means 224 is connected to the contact H.
a, 235b, if the first changeover switch means 224 is connected to the contact, a second torque calculation circuit 237;
a, 237b, respectively, and calculates the drive torque to be exerted by each of the left and right motors 41, 42.

The control torque signal output from the first torque calculation circuit 235a is transmitted to the second changeover switch means 23.
9 and is further input to the first current calculation circuit 236. Further, the control torque signal outputted from the first torque calculation circuit 235b is transmitted to the third changeover switch means 2.
40 and is further input to the second current calculation circuit 238.

The engine torque estimation circuit 243 calculates the engine torque T8 based on the engine power performance curve shown in FIG. 8 using the throttle angle signal input from the throttle angle sensor 7 and the engine rotation speed signal input from the engine rotation sensor 8. and outputs an engine torque estimation signal.

The propulsion motor torque signal calculation circuit 244 calculates the propulsion motor torque command signal to the first adder 241 and the second adder based on the engine torque estimation signal output from the engine torque estimation circuit 243 using the following formula. 242
Output to.

Tp = to, T, λ. /λ (7) Here, λ8 is the reduction ratio from the engine to the wheels, λ is the reduction ratio from the motor to the wheels, and the constant 2 is arbitrarily determined in the range of 0 to 1.0.

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

Further, the control torque signal outputted from the second torque calculation circuit 237b is added to the motor torque command value T outputted from the propulsion motor torque calculation circuit 244 in the second adder 242, and the third switching It is output to the terminal of the switch means 240.

The drive means 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 receives commands from a first chopper 312 that is connected to the power supply source 33 and the first motor 41 and adjusts the power of the power supplied to the motor, and a first current calculation circuit 236. and a first voltage/current control circuit 311 that outputs a signal to control the first chopper 312 based on the current value.

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

The power supply source 33 includes a battery connected to the first motor control device 31 and the second motor control device 32 to supply 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 drive 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 drive means 30.

The target yaw rate calculation circuit 11, the subtraction circuit 211, the first moment calculation circuit 222, the second moment calculation circuit 223, and the first torque calculation circuit 235a, 23
5b, second torque calculation circuits 237a, 237b, first current calculation circuit 236, second current calculation circuit 23
8. The motor command value calculation circuit 23, which is composed of the first adder 241 and the second adder 242, performs calculation processing by a microcomputer.

The functions performed by this arithmetic processing will be explained in detail based on FIG. 9.

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 performed in the first embodiment. Since these are the same as equations (1) to (6) in FIG. 6, their explanation will be omitted. In addition, Pl, P2, P3, P4 in the first example
, P5, P6, Pl, P8, and P9 are Pll, Pl2, Pl3, Pl9, and P2 in the second embodiment and FIG.
1, P22, P23, P24, P25, and P26, respectively.

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

m"(k) = a,"・Δω(k) 10a, +・Δω(k-1) 10m'(k-1) ・・(
4) 'Here, the gain a O' + a + ' is (4)
Set smaller than a @ and a l in the formula.

Next, in the second torque calculation circuits 237a and 237b, (5
) is similar to equation (5) to calculate moment generation torques Tl+, Tll for the left and right motors at low μ.

1゛T”t”T”, ...(5)
Next, first addition circuit 241. The second addition circuit 242 is
By adding the torque for moment generation and the torque for vehicle propulsion, the command torque T' for the left and right motors at low μ is obtained using the following formula.
Find R+T'L.

T'R=T''R+TpT'L=T''', +T,
(8) Next, the functions of the engine torque estimating circuit 243 and the changeover switches 224, 229, and 240 are also realized by a program. That is, the road surface friction coefficient μ is input in PI3, the level of μ is determined by PI3, and when it is determined that μ is high, P21, P22, P23, and the following up to P26 are executed as in the first embodiment. .

When it is determined that μ is low, read the throttle angle and engine speed with PI6, estimate the engine torque with PI3,
In PlB, the propulsion motor torque is calculated by equation (7), and PI3
Then, the required moment is calculated by equation (4), and P2O is calculated by (5).
The command torque is calculated using the formula and the formula (8), respectively, and the following steps P23 to P26 are executed.

A flowchart of the program is also shown in FIG.

The functions and effects of this embodiment having the above configuration are as follows.

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

Next, when driving on a road with low μ, execute the program using the following steps.

That is, the engine torque T0 is estimated from the throttle angle and the engine speed, and the motor torque T, which is proportional to T, is estimated.
is the motor torque required to propel the vehicle by assisting the engine, and is the same value on both the left and right sides. On the other hand, the motor torques T"R and T11. required to correct the attitude can be found using equations (4)' and (5)' if the yaw rate deviation Δω is known.The final required torque 7+ and T'L is determined by equation (8) as the sum of the propulsion torque and the moment generation torque, and based on this, the left and right motors are controlled by the motor control device as in the case of high μ.

As a result, this embodiment produces the same effect as the first embodiment on roads with high μ.

Furthermore, on roads with low μ, the motor exerts both the torque necessary to correct the posture and the torque as auxiliary propulsive force. Since the posture is corrected by the torque difference between the left and right motors, only the yaw rate can be controlled to a desired value without affecting the lateral movement of the vehicle, similar to the first embodiment. On a low μ road, the direction of the vehicle can be controlled with a smaller moment than on a high μ road, so the gain when 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 wheels, similar to a known four-wheel drive vehicle, so even though the engine is the main drive source of the vehicle on slippery low μ roads, other drive sources such as motors can be used. Can be used.

Further, in the above-described embodiment, the power supply source for attitude control is a battery, but it is not limited to this and other means can be used. For example, an engine generator may be used to adjust the output. It is possible.

[Brief explanation of the drawing]

Fig. 1 is a schematic block diagram showing the concept of the present invention, Figs. 2 to 4 show the prior art, Fig. 2 is a schematic block diagram thereof, and Fig. 3 is a problem with the prior art shown in Fig. 2. FIG. 4 is a schematic configuration diagram of another prior art, FIG. 5 and FIG. 6 show a first embodiment of the present invention, and FIG. 5 is a system diagram showing the entire system. Figure 6 is a flowchart of the computer program used in the first embodiment, Figures 7 to 9
The figures show the second embodiment of the present invention, Fig. 7 is a system diagram showing the entire system, Fig. 8 is a diagram showing the engine power performance used in the second embodiment, and Fig. 9 is a diagram showing the engine power performance used in the second embodiment. It is a flowchart of the computer program used. 1... Steering angle sensor, 2... Vehicle speed sensor, 3...
Behavior sensor, 10...Target behavior amount calculation means, 20...
- Controlled amount calculation means, 21... Deviation calculation means, 22...
・Correction amount calculation means, 23...Motor command value calculation means,
30... Drive means, 31... First motor control means,
32... Second motor control means, 33... Power supply source, 41... First motor, 42... Second motor,
51.52... Driven wheel. Figure 3 Figure 6

Claims (1)

[Scope of Claims] An attitude control device that controls the attitude of a vehicle by providing an auxiliary steering device separate from a main steering device of the vehicle, comprising: a steering angle sensor that detects the steering angle of a steering wheel; and a steering angle sensor that detects the speed of the vehicle. a vehicle speed sensor that detects the amount of vehicle behavior; a behavior sensor that detects the amount of behavior of the vehicle; and a vehicle speed sensor that takes into account disturbances acting on the vehicle or the vehicle state based on the steering angle signal output from the steering angle sensor and the vehicle speed signal output from the vehicle speed sensor. A target behavior amount calculation means for calculating an optimal target behavior amount; and a deviation calculation means for calculating the deviation between the target behavior amount signal output from the target behavior amount calculation means and the detected behavior amount signal output from the behavior sensor. and a correction amount calculation means for calculating a correction amount equivalent to the behavior amount deviation based on the behavior amount deviation signal outputted from the deviation calculation means; A motor command value calculation means for calculating a control amount commensurate with the driving force and/or braking force necessary to correct and control the posture; A control amount calculation means consisting of: A motor command signal that is the output of the control amount calculation means. a first motor control device and a second motor control device that adjust the electric power supplied to the motor based on the above, and a power supply source that is connected to the first motor control device and the second motor control device and supplies electric power to the motor. a driving means for driving a vehicle to generate a control force according to a deviation of a detected behavior amount from a target behavior amount in consideration of disturbances acting on the vehicle or the vehicle state based on the electric power controlled by the driving means; A first motor and a second motor that continuously and variably control the torque of each axis of the driven wheels to which power is not directly transmitted, and are characterized by controlling the attitude of the vehicle in a desired direction. Attitude control device for vehicles.