Abstract: The present invention provides a sensor-fault detection circuit for use with either an inductive or capacitive-type sensor. The sensor-fault detection circuit conducts a test signal into the sensor circuit for testing such sensor circuit. A time difference measuring device is provided to analyze for correct duration of the transit time of a test signal or test pulse, respectively, passing through the sensor. In the event that the transit time does not fall within a predetermined range tolerance, a fault indication can be activated. The circuit can be used, for example, to test an inductive bar-type sensor to determine the speed of a wheel on a vehicle.

Abstract: The vehicular deceleration control apparatus applies deceleration to a vehicle in accordance with the amount of operation of an accelerator. The deceleration control apparatus determines whether there is an abnormality based on a deviation between a set target deceleration and a detected actual deceleration. If an abnormality of a system is detected, the apparatus discontinues the control, and transmits a system abnormality signal to indicate the abnormality to other systems and to an operator.

Abstract: The present invention provides a vehicular brake control device which makes it possible to detect a failure or malfunction in closing an electromagnetic valve which is placed between a master cylinder and each of wheel cylinders. The vehicular brake control device includes a pressure application device which is capable of applying a hydraulic pressure automatically, i.e., regardless of a brake pedal depression, to each of wheel cylinders by way of a hydraulic pressure control device 17 from a master cylinder 20 and an ECU 18 which drives the pressure application unit 12 and the hydraulic pressure control device 17 to adjust a braking force of each of wheels. The hydraulic pressure control device 17 includes a set of pressure-maintaining and pressure-reducing valves for each wheel. The ECU 18 has a pressure application check division 77 which begins to check the pressure application at a predetermining timing.

Abstract: When the increasing gradient of the operating power is larger than a predetermined gradient, if a master pressure PM2 corresponding to a second predetermined operating power F2 is larger than a second predetermined fluid pressure Pth2, a servo function failure in the brake operation is determined; if it is smaller than the second predetermined fluid pressure Pth2, fluid leakage failure (S23, S26, S27) is determined. Furthermore, if the master pressure PM0 corresponding to the first predetermined operating power F0 is larger than a first predetermined fluid pressure Pth1, small amount fluid leakage failure is determined; if it is smaller than the first predetermined fluid pressure Pth1, large amount fluid leakage failure (S28, S29, S30) is determined.

Abstract: When it is detected that a vehicle is running on a road surface which has a coefficient of friction sufficiently low as to invite ready road wheel slippage, a control which enables the vehicle to automatically follow a preceding vehicle at a predetermined inter-vehicle distance, is inhibited. In one embodiment, when a request for vehicle follow-up is issued by the driver, and the follow-up is inhibited, the driver is informed of the low frictional coefficient of the road and is required to issue a confirmation that follow-up is required before its implementation can be carried out.

Abstract: A brake force control apparatus is provided that performs a brake assist control in which a brake force larger than that of a normal time is generated when an emergency braking is required in a vehicle, and prevents a change in a driving stability when an abnormality occurs in a vehicle characteristic changing control for maintaining the driving stability of the vehicle. When an abnormality is detected (steps 102, 106-114) in one of the vehicle characteristic changing controls, an increasing slope of a brake force of rear wheels is decreased (step 104) in the brake assist control. Alternatively, the brake assist control may be prohibited (step 140).

Abstract: A braking pressure control apparatus for a hydraulically operated brake, including a first hydraulic system having a first hydraulic pressure source power-operated to pressurize a working fluid and capable of controlling the fluid pressure, for operating the brake, a second hydraulic system having a second hydraulic pressure source operable by an operating force acting on a manually operable brake operating member, to pressurize the working fluid to a pressure higher than a level corresponding to the operating force, for operating the brake, a switching device operable to selectively establish a first state in which the brake is operated with the pressurized fluid delivered from the first hydraulic pressure source, and a second state in which the brake is operated with the pressurized fluid delivered from the second hydraulic pressure source, and a diagnosing device operable to diagnose the second hydraulic system on the basis of the fluid pressure in the second hydraulic system.

Abstract: A method and a device for generating an error signal in a motor vehicle. In this context, the vehicle has a drive engine as well as an actuating arrangement which can be actuated by the driver of the vehicle, and with the assistance of which a braking system is activated. Further, a detecting arrangement detects an actuation of the actuation arrangement. A wheel drag torque quantity is determined which represents the drag torque caused by the engine at the vehicle wheels. Moreover, a deceleration quantity is determined which represents the longitudinal deceleration of the vehicle. Furthermore, a braking quantity is determined which represents the operating state of the actuating arrangement. The error signal is then generated as a function of the determined drag torque quantity, the determined deceleration quantity, and the determined braking quantity. Thus, it is possible to perform diagnostics on the safety-relevant brake lights switch without requiring additional outlay for hardware.

Abstract: A method is disclosed for operating an electromechanical brake system 2 of a motor vehicle that contains two brake circuits 24 and 28 that are powered by the on-board network 20 in the normal mode and by the respective emergency power storage mechanisms 22a and 22b in the emergency mode. In the emergency mode of the brake system 2, one of the two brake circuits 24, 28 is only operated by the control unit 10 until the emergency power storage mechanism 22b assigned to this brake circuit 28 has reached a residual power value that is sufficient for locking the wheels of this brake circuit at least once while the motor vehicle is at a standstill.

Abstract: A method for detecting fault in vehicle motion sensors for a motor vehicle includes providing a measured lateral acceleration signal and yaw rate signal. The method further includes calculating, respectively, a first and second road bank angle estimate based on these signals. Also included is determining a first and second maximum road bank angle based on the first and second road bank angle, respectively, and calculating a first and second threshold based on these values. The method further includes comparing whether the first and second road bank angles exceeds the second and first thresholds, respectively, and if so, indicating either one or both a lateral acceleration signal fault or yaw rate signal fault.

Abstract: The speed of a pump motor in a vehicle brake control system is controlled by comparing an actual pump motor speed to a threshold speed. The actual pump motor speed is determined by measuring the pump back emf while the motor is de-energized. If the actual pump motor speed is greater than the threshold speed, the motor remains de-energized. If the actual pump motor speed is less than the threshold speed, the pump motor is energized with a pulse width modulated voltage having a variable duty cycle and a variable frequency which are functions of the difference between the actual pump motor speed and the threshold speed.

Abstract: An apparatus for diagnosing a fault in a dynamic system includes a controller which controls the dynamic system through use of a control input signal and vibrates the dynamic system through use of an vibration signal irrelevant to the internal state quantity of the dynamic system; an observer for estimating, on the basis of a response output from the vibration dynamic system, total disturbance which is a sum of an internal disturbance vector stemming from a fault in the dynamic system and a vibration disturbance vector occurring in the dynamic system through vibration; a correlation calculation unit which calculates cross-correlation between the thus-estimated total disturbance and the internal state quantity of the dynamic system and separates a component related to the internal disturbance from the total disturbance; and a diagnostic unit for diagnosing a fault in the dynamic system on the basis of the thus-separated component related to the internal disturbance.

Abstract: A compliance unit (8) for use in an hydraulic braking system is disclosed which is adapted to absorb hydraulic fluid from a master cylinder (1) during normal braking and, in the event that a fault in the braking system is detected the unit is adapted to return fluid to the master cylinder (1). The compliance unit (8) therefore effectively decreases its compliance in the event of a fault. The unit (8) may comprise a pair of pistons (14, 15) working in a stepped bore against a first and second biasing force, with a third variable biasing force provided to cancel out the second biasing force during normal operation to provide an increased compliance.

Abstract: A method of diagnosing an electrically operated brake for abnormality thereof in an automotive vehicle wherein a wheel is braked by a friction force generated by an electric motor of the brake upon an operation of a brake operating member, the method comprising the steps of: applying an abnormality checking drive signal to the electric motor to operate the electric motor while the brake operating member is placed in a non-operated position; detecting a quantity relating to an output of the electric motor while the drive signal is applied to the electric motor; and determining that the electrically operated brake is abnormal, if the detected quantity does not normally correspond to a magnitude of the abnormality checking drive signal.

Abstract: A system and method for enabling an abrupt bias fault in a vehicle motion sensor (24), such as a yaw rate sensor or a lateral acceleration sensor to be both quickly and accurately diagnosed. When a potential fault is first indicated, it is signaled as true only if the vehicle is in a stable state and vehicle vibration is ruled out as a cause of abrupt signal change. Processing of signals is conducted by microprocessor.

Abstract: A status of one or more subsystems positioned on one or more trailers is communicated to a tractor electrically and mechanically connected to the trailer. The status may be automatically supplied by the subsystem or may be requested either by the operator of the tractor/trailer combination or automatically by another subsystem on either the tractor or the trailer. A spread spectrum data communications signal representing the status of a respective subsystem is superposed on the power bus. The status of the respective subsystem can then be determined from the spread spectrum data communications signal. Preferably, the status of the subsystem is indicated to an operator positioned on the tractor. A command for controlling a subsystem on a trailer can also be communicated from the tractor to the trailer over the power bus. A spread spectrum data communications signal representing the command is produced on the power bus, and the subsystem is controlled based on the spread spectrum data communications signal.

Abstract: The invention relates to a method and device for controlling braking force distribution in a motor vehicle. In the case of failure of the braking system, the braking force distribution regulator enters emergency mode. The regulation is activated when the speed and the deceleration of the vehicle exceed given minimum values. The invention also concerns emergency measures for regulating the braking force distribution in the case of the certain individual errors.

Abstract: A method of monitoring a brake system which is equipped with anti-lock control (ABS) and a system for electronic control of brake force distribution (EBV). The system includes two brake circuits in a black/white brake circuit split-up, the EBV function or control is principally released only when the vehicle deceleration exceeds a predetermined limit value (GWN). To identify a front-axle brake circuit failure, acceleration criteria, i.e., criteria responsive to the acceleration behavior of the vehicle wheels, are predetermined and monitored. Further, slip range monitoring in conjunction with acceleration range monitoring is performed.

Abstract: A method and an apparatus for controlling a braking system of a vehicle. The braking action is established or regulated at at least one wheel brake, by electrical structure, as a function of a driver's braking input. A capability for conventional action by the driver is cut off by a valve. A pressure medium is enclosed in a portion of the braking system. In at least one operating state in which an expansion in the volume of the enclosed medium may be expected, the valve is briefly opened in order to reduce the expansion in volume.

Abstract: A method of predicting a minimum stopping distance required to stop a subject vehicle by a braking system thereof, including: (a) a step of obtaining measurement data for each of at least one sample vehicle which is braked by a braking system thereof operated with its full braking capacity, the measurement data including a weight and a running speed of the sample vehicle, a stopping distance through which the sample vehicle has run to be stopped, a tire radius of the sample vehicle, and optionally a tire width of the sample vehicle; (b) a step of obtaining at least one predicting equation on the basis of the measurement data in a statistical manner, the equation providing a predicted value of the minimum stopping distance on the basis of a weight, a running speed and a tire radius of the subject vehicle, and optionally a tire width of the subject vehicle; and (c) a step of calculating the predicted value of the minimum stopping distance, by substituting the weight, the running speed, the tire radius of the ru

Abstract: A controller for a hydraulic control system includes a microprocessor having a diagnostic routine. The diagnostic routine is operable to exercise an arithmetic logic unit within the microprocessor to verify that the arithmetic logic unit is functioning properly. Upon detection of a malfunction of the arithmetic logic unit, the diagnostic routine disables the hydraulic control system and generates a warning signal.

Abstract: A fluid pressure source apparatus has a pump, an accumulator, a pressure switch, and a control device for turning on and off the pump in accordance with the signal from the pressure switch. The control device has a pressure increase control unit. When the pressure detection signal of the pressure switch indicates a high pressure, the pressure increase control unit estimates a pressure reduction N resulting from a fluid pressure consumption by a fluid pressure circuit. If the estimated amount of pressure reduction N exceeds a set value KN=KN1, KN2, the pressure increase control unit drives the pump for a set time KT=KT1, KT2, thereby ensuring a predetermined range of accumulator pressure despite a possible failure of the pressure switch or sensor.

Abstract: A hydraulic automotive vehicle brake system with an actuating assembly that is attached to the splashboard of the automotive vehicle and is operable by the vehicle brake pedal. In order to reduce the possibility of risk to the driver during a collision (especially a rear end collision), the present invention provides a system which simulates an increase volume requirement of the brake system, thus permitting increased actuating travel of the actuating assembly.

Abstract: An apparatus and method for testing, for example, ABS systems in which a variable reluctance detector is positioned adjacent a ring of ferromagnetic teeth mounted on a wheel is provided. The amplitude and period of individual cycles of the output of the detector are measured and the product of the measured amplitude and period is calculated to provide an indication of the performance of the ABS detector system. The rate of change of the product may be analyzed to more reliably distinguish fault conditions from the effects resulting from, for example, variations in the speed of the wheel. The peak-to-peak amplitude of the product may be monitored to indicate tooth eccentricity, and the mean of the product may be monitored to indicate the detector-to-tooth gap.

Abstract: A circuit arrangement for safety-critical control systems, for example, for the control of anti-lock brake systems, is based on an at least partly redundant processing of input data which are taken into account for generating control signals. The control system is disconnected upon non-correlation of the signals. A microprocessor system is provided for data processing and includes two or more central processor units permitting parallel processing of the input data. The output data of the CPUs are checked for correlation. Each write/read memory of the microprocessor system has a generator to generate a test information. The write/read memories and the read-only memories are extended by memory spaces for the test information. In every writing or reading access to the memories, the contents of the memory space is tested with the associated test information for correlation, and an error identification signal is generated in the absence of correlation or plausibility.

Abstract: In a vehicle motion control system, a target rear-wheel steering-angle calculating section calculates a target rear-wheel steering angle, a rear-wheel steering-quantity setting section sets a rear-wheel steering quantity, and a rear-wheel steering signal output section outputs a rear-wheel steering quantity to a motor driving section to perform a steering angle control. In addition, a front-and-rear wheel steering response-parameter calculating section calculates a response parameter, and a front-and-rear wheel steering target yaw-rate calculating section calculates a target yaw rate. A yaw-rate difference calculating section calculates a yaw-rate difference, a target braking-force calculating section calculates a target braking force, and a braked-wheel discriminating section selects a wheel to be braked.

Abstract: A control system for motor vehicles in which the errors in wheel velocities created by tolerances between the tires are compensated.

Abstract: This invention relates to a braking control system for an electric automobile that runs by driving wheels with an electric motor. The braking control system controls braking of a vehicle through regenerative braking by the motor. Upon application of brakes, the braking control system can make combined use of mechanical braking by a mechanical brake system (11) and regenerative braking by a drive motor (2). The braking control system is designed to control regenerative braking of the motor (2) by a regenerative braking control device (12) so that greater braking force is produced when a failure in the mechanical brake system (11) is detected by a failure detection device (22) than when the mechanical brake system (11) is detected to be normal.

Abstract: An anti-lock braking system as well as the method thereof, is capable of recording the operating conditions of elements thereof. The anti-lock braking system includes a microcomputer having first and second memories. The method includes a step for resetting data stored in the second memory. A slip rate of a wheel, electric signals applied to both motor and a solenoid valve assembly, an output voltage and a RPM of the motor, an output pressure of a pump, and a pressure of a fluid passing through the solenoid valve assembly are permanetly recorded in the second memory. By using the anti-lock braking system, the user can easily find a malfunctioned element of the anti-lock braking system and can save the time and money normally used in checking the anti-lock braking system when the anti-lock braking system malfuntions.

Abstract: An electronic controller applies a braking force to selected wheels when sudden tire rupture is detected. A tire rupture signal indicative of whether a tire on the vehicle has ruptured is generated. Signals corresponding to a desired trajectory of the and the actual trajectory of the vehicle are calculated. Corresponding brake actuator signals are generated and applied to appropriate brakes of the vehicle, controlling the actual trajectory of the vehicle.

Abstract: A control device for an automotive vehicle comprises a differential disposed between wheels or wheel axles of a vehicle an antiskid brake control device to control an antiskid brake device which is capable of adjusting a brake pressure applied to a brake device of the vehicle to prevent wheels of the vehicle from locking, a differential limiting control device having a differential limiting device being capable of controlling and transferring a differential limit to the differential, and operating to decrease the differential limit while the antiskid brake device is operating, such that when either the antiskid brake control device or said differential control device fails, the non-failing control device receives a failure signal from the failing control device and the non-failing control device controls the vehicle towards a stable condition or increases a brake force.

Abstract: In a circuit arrangement for a brake system with anti-lock system and/or traction control with input circuits, output circuits, control circuits, monitoring circuits, comparator circuits and circuits for switching off the control in the event of a fault, a continuous monitoring of the control circuits and of the monitoring circuits is made possible. Both the control circuits and the monitoring circuits comprise watchdog circuits for processing a watchdog algorithm which tests the functioning of the control circuits and monitoring circuits and comparator circuits for comparing the results of the watchdog algorithms respectively processed in the watchdog circuits. The output circuits only enable the control if both the control signals output by the control circuits correspond to the corresponding signals of the monitoring circuits and the results of the watchdog algorithms respectively processed in the watchdog circuits correspond.

Abstract: To enhance the reliability of a brake system with electronic control of the brake force distribution, a short pressure reduction pulse, which is negligible for the braking process, is applied to the front wheels (VR, VL) during a braking operation, and the reaction of the front wheels to the pressure reduction pulse is sensed. If imbalance of the front-wheel brakes or a defect is concluded from the reaction, the limitation of the pressure rise in the wheel brakes of the rear wheels (HR, HL), which is an effect of the brake force distribution control, is minimized or eliminated. Thus, the rear wheels provide an increased contribution to the braking process in this situation.

Abstract: Method of providing brake retardation capability safety check. Method includes generating a signal representing vehicle mass, and combining it with an electric brake feedback signal and a brake cylinder pressure signal to generate a signal representing vehicle deceleration rate. Integrating the signal representing vehicle acceleration rate to generate an output signal representative of a process cycle speed reduction value. Inputting and storing values of process cycle speed reduction output signals to and in, respectively, a summation unit. Adding such values inputted to summation unit to a predetermined number of seconds worth of process cycle speed reduction values and generating output signal representative of braking effort available in terms of speed reduction over such predetermined number of seconds. Inputting brake command signal to brake command jerk limiting unit.

Abstract: A failure detecting apparatus for an anti-skid brake control system of a motor vehicle comprises a main microcomputer for generating a hydraulic pressure control signal for controlling an actuator adapted to generate braking efforts to be applied to wheels of the motor vehicle, an auxiliary microcomputer for detecting occurrence of a failure in the main microcomputer on the basis of the hydraulic pressure control signal, a test signal generating means implemented in the main microcomputer or the auxiliary microcomputer to generate a test signal, an anti-skid brake control arithmetic means incorporated in the main microcomputer to generate a hydraulic pressure control signal on the basis of either a wheel speed signal or the test signal, and a hydraulic pressure control signal monitoring means implemented in the auxiliary microcomputer to monitor the hydraulic pressure control signal generated in response to the test signal, to thereby check the validity of the hydraulic pressure control signal.

Abstract: A circuit configuration for a brake system with anti-lock control and/or traction slip control composed of circuits for conditioning wheel sensor signals, controller circuits for analyzing and processing the conditioned sensor signals and for generating braking pressure control signals, monitoring circuits which process the sensor signals irrespective of the controller circuits, and circuits for exchanging and comparing signals of the controller circuits with corresponding signals of the monitoring circuits. The monitoring circuits have a simpler structure than the controller circuits. The control philosophy is reproduced in the monitoring circuits. In particular, the control phases are determined by the reproduction on the basis of the same control criteria and control parameters which the controller circuits use. The signals of the reproduction circuits are united with the valve-excitation signals in correlation circuits for the detection of errors.

Abstract: The invention proposes a process for error recovery in electronic control devices as well as apparatus for controlling the steering angle of the rear wheels of a motor vehicle. The control device controls an actuating member to which is connected a safety device. In the main operation of the control device, transmitter signals are detected, actuating values are calculated and the actuating member is controlled corresponding to the calculated values. The calculated actuating values and the detected transmitter signals are checked for consistency. On the basis of the checked values, a decision is made as to whether to continue running the main program or resort to one of two emergency measures. In the first emergency measure, the safety device is activated and the control of the actuating member is switched off. In the second emergency measure, the signals of transmitters continue to be detected and actuating values are calculated from these signals.