Abstract: An anti-lock braking system (ABS) for multi-axle vehicles equipped with multiple wheel-speed sensors and modulators for adjustment of braking pressure. The brake cylinder for each wheel may be controlled by an individual modulator, or, alternatively, a single common supply axle modulator may regulate both brake cylinders of an axle. In a preferred embodiment, the ABS is controlled by an ABS electronic control unit (ECU), which has four regulating channels with four corresponding end stages for controlling three modulators, where one of the modulators is commonly regulated by two end stages. The ECU also detects whether it is coupled to a proper ABS. The ABS electronic control unit eliminates the danger of an undetected installation of an ABS electronic control unit into an incompatible anti-lock braking system.

Abstract: An automatic deceleration control apparatus for a vehicle operates so as to secure appropriate tire grip performance, depending on the conditions of a road surface on which the vehicle runs turning, and restrain excessive rolling of the vehicle body, there by stabilizing the turning behavior of the vehicle at all times. While the vehicle is turning on a high-friction road surface without undergoing haw moment control, a safe vehicle speed is computed within the rollover limit of the vehicle. While the vehicle is turning on a low-friction road surface under haw moment control, on the other hand, a safe vehicle speed that ensures satisfactory tire grip performance is computed in accordance with an estimated road friction coefficient. When the vehicle is about to exceed its safe speed as it turns, it is automatically decelerated to the safe speed or below. Thus, the vehicle can be prevented from spinning, drifting out, or rolling over.

Abstract: A tire pressure monitoring system and method for vehicles equipped with anti-ing lock breaking systems (ABS), especially vehicles with more than two axles, is provided. Wheel sensors associated with the ABS are utilized to sense variables which depend on wheel rotation, such as speed of rotation of the wheels or travel distances covered by the wheels. An ABS control unit logically combines the determined variables with one another and performs an evaluation with respect to change of rolling radii of the wheels while allowing for changes of the variable caused by driving operation. The ABS control unit generates a warning signal when the change of variables caused by tire pressure decrease exceeds a preselected limit value. In addition to the wheel sensors, a tire pressure measuring system which measures the absolute tire inflation pressure of the wheels of at least one axle and generates a warning signal when the measured tire inflation pressure drops below a preselected setpoint pressure can be utilized.

Abstract: A process for the verification of an antilock braking system (ABS) in a vehicle to check for correct connection of the component wheel sensors (3, 4, 17, 18, 19, 20), braking pressure modulators (7, 9, 12), and brake cylinders (5, 6, 10, 11, 13, 14) is proposed. The method can be used in a new installation of the ABS or when resuming operation after repair of the system. In a first step, the user causes a single sensed wheel to rotate. This actuates a testing mode in the ABS electronic controller (8). The electronic controller (8) then actuates the modulator belonging to the rotated wheel. From the response of the sensed wheel and/or the actuated modulator, the user recognizes whether the matching between the sensor of the rotated wheel and the actuated modulator is correct. This procedure is then repeated with the other sensed wheels.

Abstract: A method is provided for the generation of wheel acceleration control signals and wheel deceleration control signals for an anti-lock system for wheels of a vehicle. The vehicle is furnished with a digital electronic anti-lock system with at least one microprocessor. The microprocessor calculates a wheel comparison speed (v.sub.diff). The wheel comparison speed is obtained by a filtering of the actual wheel speed (v.sub.wheel), and follows in time to the actual wheel speed (v.sub.wheel). A deceleration signal (-b) or an acceleration signal (+b), respectively, is then furnished when the absolute value of the difference (.DELTA.) between the wheel comparison speed (v.sub.diff) and the actual wheel speed (v.sub.wheel) surpasses a preset value as based on the sign of the difference (.DELTA.).

Abstract: An error detection and display system for an apparatus having first and second operating states comprises a testing device, a display unit (e.g., a warning light), and a switch-on control unit. The testing device runs primary error test cycles for detecting errors of a first kind which occur during the first operating state of the apparatus (e.g., a vehicle at standstill), and secondary error test cycles which occur and can be detected only in the second state of the apparatus (e.g., the vehicle moving above a predetermined minimum speed). The system also includes a non-volatile memory wherein all occurrences of errors of the second kind are stored. The switch-on control unit switches on the testing device and the warning light when the vehicle is first started. If no error of the first kind is detected by the testing device and no error of the second kind is stored in the error memory, the switch-on control unit switches off the warning light while the vehicle is still at a standstill.

Abstract: An electronic circuit, in particular for an anti-skid protection system for vehicles is provided with at least with one microcomputer (2). The microcomputer (2) controls a load (4) via a final amplifier (3). A resistor circuit (6, 7, 8) is furnished for surveillance of the final amplifier (3) as well as of the load (4). The resistor circuit (6, 7, 8) is disposed parallel to the final transistor (5). The microcomputer (2) or a separate control circuit scans the voltage at the junction nodal point (9) between the final transistor (5) and the load (4) at predetermined points in time and checks it for appropriate level. The resistor circuit (6, 7, 8) is connectable via an electronic switch (10, 11), controlled by the microcomputer (2) or by the separate control circuit, as desired with the operating voltage U.sub.B or with ground. The circuit allows a distinction of errors of the final transistor (5) and of the load (4).

Abstract: A circuit for the surveillance of the switching state of a power transistor is constructed such that both, the voltage applied to the power transistor (1) is surveyed by way of a voltage comparator (7), as well as the voltage applied to the load (3) is surveyed by way of a further voltage comparator (8). The comparator (7) in the switched-on state and the comparator (8) in the switched-off state are activated by the input signal (U.sub.IN) of the power transistor (1). The output signals of the two comparators (7, 8) are combined to a status signal (U.sub.Stat). It is possible by way of the proposed circuit to recognize both a short circuit or, respectively, a shunt circuit of the load as well as a leakage current of the power transistor (1) and thus an interruption of the load occurs.

Abstract: A circuit arrangement for protecting the antilocking electrical system from overvoltages developed in the vehicle's electrical systems. Such overvoltages can be caused by a load dump and can lead to destruction of the vehicle's electrical system. To sense an overvoltage condition, a test circuit is provided which is connected to the vehicle's electrical system. The voltage test circuit provides an output signal when the voltage of the vehicle's electrical system exceeds a first threshold value. This output signal is used to switch the final stage of the antilocking electrical system. The overvoltage is thereby conducted directly to one or more low-resistance solenoid valves which limit the voltage in such a way that it no longer presents any danger to the vehicle's electrical system.

Abstract: A protection circuit for monitoring and recognizing an undervoltage condition in the electrical system of a motor vehicle having an anti-skid brake control system in order to minimize and reduce any adverse effects on the braking action of the vehicle wheels. The protection circuit includes at least one comparator circuit to recognize if the voltage falls below a predetermined reference threshold voltage. When the supply voltage falls below the threshold voltage, the comparator circuit deactivates at least one of two diagonal switching circuits to remove automatic brakes on at least two wheels of a vehicle by the anti-skid brake control system.

Abstract: A multiplex cabling system for controlling electrical apparatus on motor vehicles, which consists of a central transmitter and several area transmitter-receivers, each connected to several controlled devices and/or indicators. Coupling between the central transmitter and the area units is made by a star-arranged line system which consists of a separate, two-wire connecting channel between the central transmitter and each area transmitter-receiver. To further increase the system's reliability and security, the central transmitter includes two microprocessors which are normally assigned to control a different pair of diagonally-opposite area transmitter-receivers. If one processor fails, the other unit assumes full system control.

Abstract: An arrangement for monitoring the function of a programmable electronic switching circuit, such as, a microprocessor or microcomputer, characterized by a monitoring switch is associated with and is connected with the reset input and the clear input of the programmable electronic switching circuit and the monitoring switch includes a measuring circuit for determining the program length.

Abstract: A circuit arrangement for influencing the brake pressure venting phase and/or brake pressure retaining phase for an antiskid vehicle braking system when the measured velocity difference deviates from a given velocity difference during controlled braking. The velocity change is determined as a function of the wheel tendency or tendencies by measuring and differentiating the velocity value or values at the interval boundaries of an assigned time .DELTA.t of the control signals or by the assigned times of the control signals. A switching circuit, to which the brake pressure control signals, such as, the acceleration +b, deceleration -b and slip .lambda. control signals, and a signal representing the wheel tendencies, such as, either positive or negative velocity change of the sensed wheel or wheels, can be set upon drop away of a +b or -b signal. The switching circuit controls a shifting circuit which changes the assigned time .DELTA.t or some or all assigned times .DELTA.

Abstract: A speed measuring circuit for digitally determining the angular speed of a rotating object employing a sensor and control unit for producing a sequence of signals proportional to the speed of the rotating object and for measuring the speed which is inversely proportional to the cycle duration. A storage register for storing a certain number of fixed values which are associated with certain speed values and which are graduated as preset of a predetermined speed measuring range. A comparator and control unit for comparing the cycle duration value measured each time with the fixed values and for setting the measured value equal to one of two successive speed step values when the measured value falls within the speed interval which is limited by the two successive speed step values.

Abstract: This disclosure relates to a method and an arrangement for filtering disturbing signals in the digital measurement of the cycle duration for an antiskid control system for motor vehicles. The detrimental influence of short disturbances on the production of control signals is suppressed by means of the filtering process. The production of the control signals takes place in accordance with the result obtained from a comparison of the respective measured value .tau..sub.n with a reference value .tau..sub.B. The filtering is carried out in a manner so that when a digital measured value .tau..sub.n enters, a new reference value .tau..sub.B', is produced as a function of the difference between the reference value .tau..sub.B and the mean value obtained from the reference value .tau..sub.B and new measured value .tau..sub.n.

Abstract: A digital speed detecting circuit of the type in which pulses of a clock frequency are counted during a time interval of a cycle of the sinusoidal signal obtained from a sensor of the rotating member whose speed is being measured. The pulse count throughout the speed range of the rotating member is adjusted to be within a range best suited for accurate evaluation, since the pulse count exceeds this range at high and low speeds. This is accomplished in a first embodiment by shifting to a different counting frequency in different speed ranges and correcting the speed signal obtained by a factor corresponding to the degree of frequency change. In a second embodiment, the counting frequency is monitored and adjusted each cycle of the sinusoidal signal by comparing in a shift register the stage of advancement of a binary counter that produces the pulse count with a reference stage establishing the upper limit of the evaluation range.

Abstract: An antiskid control system for a vehicle in which acceleration and deceleration control signals are generated by a control circuit in accordance with the rotational speed of a wheel monitored by a sensor device that produces a pulse train whose frequency varies with wheel speed. A digital counter operates for the duration of each pulse cycle of the sensor signal whereby the pulse count obtained represents a cycle duration of the sensor signal. Within the control circuit to which the sensor signal is supplied, a control unit transfers the pulse count after each cycle to a first shift register as a measure of the cycle duration. The first shift register outputs the pulse count of the measured cycle duration to a comparator to which there is also connected a pulse count of a reference cycle duration supplied by a second shift register to which the pulse count of a previous measured cycle duration has been supplied by the first shift register to form the reference cycle duration.

Abstract: A checking circuit for periodically monitoring the electronic operating reliability of a vehicle antiskid control system during periods of operation, as well as prior to operation, by injecting a periodic test pulse into the system control channel. An evaluation circuit detects the transmission of the test pulse by the control channel and output amplifier as an indication of the ability of the electronic devices to effect a subsequent energization of the system modulator valve at the time of de-energization thereof, or de-energization of the system modulator valve at the time of energization thereof. A warning device is activated in the absence of a test pulse transmission within a predetermined time duration following generation thereof.

Abstract: A signal multiplier circuit in which a sinusoidal input signal corresponding to the angular velocity of a rotating member, such as a vehicle wheel, is connected directly to one input of each comparator of a positive and a negative polarity responsive network. The sinusoidal input signal is concurrently connected to the other input of each comparator via a signal modifying circuit whose output deviates from the sinusoidal input signal, consequently effecting operation of the respective comparators a predetermined number of degrees beyond the positive and negative transitions of the sinusoidal input signal. Each comparator output is thus phase displaced relative to the other and is connected via logic circuits which provide a signal whose polarity alternations are a multiple of the sinusoidal input signal generated to thereby provide a more accurate response of wheel anti-skid signal sensing circuitry at low vehicle speeds.

Abstract: In an anti-skid brake control system for a wheeled vehicle, an electronic circuit for generating a wheel speed signal in accordance with the time duration of a half cycle of a sinusoidal waveform generated by a sensor that detects the presence or absence of teeth of a rotor that revolves with a wheel of the vehicle is arranged so that the measured time duration of both a positive and a negative alternation of the waveform is utilized to obtain accurate wheel skid control at relatively low speeds. Slight differences in the measured time duration of a positive and negative half cycle due to slight variations in the dimensions of a tooth and adjacent space are sensed and modified as required to assure correspondence between the measured time durations in order to avoid false sensing of a wheel skid condition.