Abstract: A solenoid drive circuit is provided with an energization controller that controls the energization/de-energization of a coil and is disposed either between a power source and the coil or between the coil and ground. A diode allows electric current to flow toward the power source and is connected between the power source and ground while bypassing the coil. A switch is provided either between the power source and the diode or between the diode and ground. Therefore, it is possible to easily switch between a state in which the electric current flowing through the coil is gradually reduced and a state in which the electric current flowing through the coil is rapidly reduced by switching over between conduction and cutoff of the switch.

Abstract: An electric power steering system for a vehicle that consists of a motor control signal calculation device for calculating a motor control signal for driving a motor to generate a steering assist torque, which is based on at least a steering torque detected by a steering torque sensor, a motor control signal correction calculation device for calculating a corrected motor control signal from an amount of motor control signal correction calculated by an external control device and the motor control signal, a driving device for driving a motor based on the corrected motor control signal calculated by the motor control signal correction calculation device; and a motor control signal correction amount reducing device for reducing the amount of motor control signal correction according to vehicle speed.

Abstract: A co-operative control system for a vehicle including a force distribution device for distributing the driving force or braking force between the right and left wheels or between the front and rear wheels, includes a first control means for controlling the operation of the force distribution device, an electric power steering device, having a motor for applying a steering assist torque to a vehicle steering system, and a second control means for calculating a motor control signal for driving the motor. The motor control signal is based on at least the steering torque detected by a steering torque detecting means.

Abstract: A co-operative control system for a vehicle having a force distribution device for distributing at least one of a driving force and a braking force between spaced apart wheels, the co-operative system having: a first control mechanism for controlling the operation of the force distribution device, an electric power steering device having a motor for applying a steering assist torque to a steering system of the vehicle, and a second control mechanism for calculating a motor control signal for driving the motor based on at least a steering torque detected by a steering torque sensor, and for inhibiting drive of the motor based on at least an actual motor detected by a current sensor and the steering torque.

Abstract: A left hydraulic pump 3L connected to a left wheel and a right hydraulic pump 3R connected to a right wheel are interconnected by a first oil passage 21 and a second oil passage 22 to constitute a closed circuit. First and second variable throttle valves 8L and 8R are mounted between the first and second oil passages 21 and 22 and a tank 6. A first on-off valve 11L is disposed between two working chambers 9L.sub.2 and 9L.sub.3 of the left hydraulic pump 3L and the second oil passage 22, and a second on-off valve 11R is disposed between two working chambers 9R.sub.2 and 9R.sub.3 of the right hydraulic pump 3R and the first oil passage 21. For example, if the first variable throttle valve 8L is throttled, the pressure in the first oil passage 21 is risen to open the first on-off valve 11L, thereby increasing the amount of oil discharged from the first hydraulic pump 3L.

Abstract: A brake system for a vehicle includes a liquid pressure generating device for generating a liquid pressure for braking dependent upon a manual operation, an actuator for generating a liquid pressure for braking dependent upon an electrical command signal, and an electromagnetic switchover valve which is switchable between a first state in which a wheel brake is connected to the liquid pressure generating device upon deenergization of the electromagnetic switchover valve, and a second state in which the wheel brake is connected to the actuator upon energization of the electromagnetic switchover valve. The brake system further includes a controller.

Abstract: A left hydraulic pump connected to a left wheel and a right hydraulic pump connected to a right wheel of a vehicle are connected by a first oil passage and a second oil passage to constitute a closed circuit, and first and second variable throttle valves are provided between the first and second oil passages and the tank. Either one of the first and second variable throttle valves is throttled to cause the first and second hydraulic pumps to produce a braking force and a driving force, respectively, thereby controlling a yaw moment. At the same time, when either one of left and right wheel suspensions expands, the roll rigidity of the vehicle increases or decreases to vary the cornering forces of the wheels, thereby producing a yaw moment which assists in the yaw moment produced by the first and second hydraulic pumps.

Abstract: In an antilock brake control for a vehicle for individually regulating braking forces of left and right wheel brakes in accordance with a locking tendency of left and right wheels during braking of the vehicle, a steering angle, a vehicle speed and a yaw rate of the vehicle are detected. A reference yaw rate is determined based on the steering angle and the vehicle speed. When a locking tendency of only an outer wheel during turning of the vehicle, of the left and right wheels is detected during turning of the vehicle, the braking force for the outer wheel is regulated in accordance with the tendency of the outer wheel, and the braking force for an inner wheel during turning of the vehicle is regulated in accordance with a difference between the reference yaw rate and the detected actual yaw rate. Thus, it is possible to enhance the turning characteristic while avoiding a loss in total braking force during turning of the vehicle.

Abstract: In a brake control system for yaw control in a vehicle, the conditions for starting a brake operation are that the absolute value of a deviation between a target yaw rate determined in a target yaw rate determining device and an actual yaw rate detected by a yaw rate detecting device is equal to or greater than a preset deviation value and that the absolute yaw rate is equal to or greater than a preset value. The wheel brake for an outer wheel, during turning of the vehicle, is operated by the yaw control system based on the deviation between both the yaw rates. However, brake control does not occur when both of the yaw rates are the same in direction and are large. Thus, yaw control is conducted immediately when necessary, but the conduction of unnecessary yaw control is avoided, thereby reducing the frequency of the brake operation.

Abstract: A brake system for a vehicle includes a liquid pressure generating device for generating a liquid pressure dependent upon a manual operation, actuators having output ports for outputting a liquid pressure dependent upon an electrical command signal from a controller, and which are adapted to be connected to a reservoir when the actuators are non-operative, and switchover valves switchable between a state in which wheel brakes are connected to the liquid pressure generating device, and a state in which the wheel brakes are connected to the actuators. In the brake system, on-off valves are connected between the output ports of the actuators and the switchover valves, and are opened when the liquid pressures output from the actuators is equal to or higher than a predetermined value.

Abstract: A total longitudinal force which is a sum total of the longitudinal forces applied to the plurality of wheels is detected or determined, and the longitudinal forces applied to the wheels are controlled on the basis of a front wheel-side target wheel longitudinal force and a rear wheel-side target wheel longitudinal force determined by distribution of the total longitudinal force at predetermined distribution proportions. When the slipping of a wheel is detected, the distribution proportions are changed, so that the target wheel longitudinal force is larger on one of the front and rear wheel sides in which more wheels are in non-slipping states.

Abstract: An antilock brake control system for a vehicle is capable of switching between an individual control mode and a collective control mode. The individual control mode regulates the braking forces of left and right wheel brakes in accordance with locking tendencies of the left and right wheels during braking. The collective control mode collectively regulates the braking forces of the left and right wheel brakes in accordance with one of the detected locking tendencies of the wheels, the direction of a vehicle's yaw rate and the steering direction. When these directions coincide with each other, the individual control mode is selected, but when these directions do not coincide with each other, the collective control mode is selected. Thus, it is possible to easily determine a state where the friction coefficients of the road sections, with which the left and right wheels are contacted, are different. Thus, stability is insured in the collective control mode.

Abstract: A traction control device for a vehicle decreases the driving torque for a driving wheel connected to a power source through an automatic transmission in response to the detection of an excessively slipping tendency of the driving wheel at the time of acceleration of the vehicle. In the traction control device, the shifting motion of the automatic transmission is predicted by a shifting predicting means based on operational parameters of the power source and a shifting characteristic of the automatic transmission. The operational parameters of the power source are assumed by an foreseeing means based on values before shifting of the operational parameters of the power source and operational parameters of the vehicle as well as gear shift positions detected before and after shifting by a gear shift position detecting means.

Abstract: A brake system for a vehicle includes a master cylinder for outputting a liquid pressure corresponding to a braking operation quantity, an electric actuator capable of outputting the liquid pressure corresponding to the braking operation quantity, and a switch-over valve capable of switching the connection and disconnection between the master cylinder and wheel brake. The electric actuator is connected to the wheel brake to block the back flow of a working liquid from the wheel brake. Braking pressure applied to the wheel brake is detected by pressure detector. When a difference between the detected braking pressure and a target braking pressure corresponding to the braking operation quantity exceeds a predetermined range, an output liquid pressure from the master cylinder is applied to the wheel brake.

Abstract: A traction control device for a vehicle includes a control unit for operating wheel brakes for left and right driven wheels connected to a power source through a differential, when an excessively slipping tendency is produced in one or both of the driven wheels. In the traction control, an input torque supplied from the power source to the differential is detected by an input torque detecting device. A limit driving torque is determined based on a detection value detected by the input torque detecting device at the time when it is detected by a slip detecting device that only one of the driven wheels is fallen into the excessively slipping tendency. A braking torque to be applied to the one driven wheel is determined based on a value resulting from the subtraction of the limit driving torque from a current detection value detected by the input torque detecting device.

Abstract: A total longitudinal force which is a sum total of the longitudinal forces applied to the plurality of wheels is detected or determined, and the longitudinal forces applied to the wheels are controlled on the basis of a front wheel-side target wheel longitudinal force and a rear wheel-side target wheel longitudinal force determined by distribution of the total longitudinal force at predetermined distribution proportions. When the slipping of a wheel is detected, the distribution proportions are changed, so that the target wheel longitudinal force is larger on one of the front and rear wheel sides in which more wheels are in non-slipping states.

Abstract: A braking force control system of a vehicle, capable of independently controlling at least braking forces of front wheel brakes, a braking force of a left rear wheel brake and a braking force of a right rear wheel brake. The braking force control system includes front wheel-side controls for controlling the braking forces of the front wheel brakes on the basis of a quantity of operation of a brake operating member and a deceleration of the vehicle, and rear wheel-side controls for independently controlling the braking forces of the left rear wheel brake and the right rear wheel brake on the basis of a turning level of the vehicle. Thus, it is possible to provide a sufficient braking force, while stabilizing the behavior of the vehicle, during braking in a turning state of the vehicle, by conducting a control of deceleration for the front wheels increased in load during braking, and by conducting a control of turning for the rear wheels largely contributing to the control of turning.

Abstract: A target torque is determined in a target torque determination device on the basis of an accelerator operation amount detected by an accelerator operation amount detector and power source output detected by a power source output detector. A target driving force is determined in a target driving-force determination device on the basis of driving force detected by a driving-force detector and the target torque. A target acceleration is determined in a target acceleration determination device on the basis of a travel resistance detected by a travel resistance detecting device and the target driving force. The operation of an actuator is controlled on the basis of an acceleration detected by an acceleration detecting device and the target acceleration. Thus, it is possible to provide a power source output control in accordance with the travel resistance, while simultaneously taking into consideration the current state of the power source and the responsiveness thereof.

Abstract: An anti-lock control method for a vehicle includes the steps of: calculating an operation control quantity on the basis of a braking pressure at the start of an anti-lock control when a wheel is about to be locked during braking, and controlling the operation of an actuator, capable of adjusting the braking force of a wheel brake by the operation control quantity in order to reduce the braking force. In this process, the braking pressure at the start of anti-lock control is corrected with the locking tendency of the wheel to set an adjusted reference braking pressure, and the operation control quantity is calculated on the basis of the adjusted reference braking pressure. Thus, it is possible to determine the reference braking pressure with good accuracy, leading to an enhanced accuracy of the anti-lock control.

Abstract: A method for preventing the slipping of a vehicle engine during braking, by judging whether or not there is an excessive slipping of driven wheels on the basis of detection values detected by driven wheel speed detectors for detecting driven wheel speeds and detection values detected by follower wheel speed detectors for detecting follower wheel speeds, such that if it is decided that there is excessive slipping during engine braking, an actuator capable of changing the output from an engine mounted in the vehicle is operated to increase the output from the engine, wherein the method comprises steps of: detecting a gear position in a transmission disposed between the engine and driven wheels; determining a target engine revolution number on the basis of the gear position and the detection values of the follower wheel speeds at the time when it is decided that there is the excessive slipping; and determining a control amount for operation of the actuator on the basis of the target engine revolution number.