摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A wheel speed measuring apparatus is provided for use in an anti-skid brake control system such that a digital speed signal is obtained having good accuracy without resorting to expensive manufacturing methods to assure exact conformity of the teeth and teeth spaces of the rotor member of the wheel sensor device used in the anti-skid control system. The speed measuring apparatus consists of at least two corresponding portions, each consisting of a control unit, a counter and a data register. The control unit of one portion responds to a positive polarity transition of the square wave signal generated by the wheel sensor, while the control unit of the other portion responds to negative polarity transitions, to initiate operation of the respective counters. The count output of each counter therefore provides a digital speed signal corresponding to a full cycle duration of the square wave signal, with one cycle overlapping the other to compensate for any deviations in the half-cycle durations due to size differences in the teeth and spaces of the rotor member of the sensor that generates the square wave signal.
摘要:
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. The reference cycle duration and measured cycle durations are compared to obtain a difference signal which is subsequently compared to an admissible difference signal to provide the acceleration and deceleration control signals when the difference exceeds a preselected amount. The admissible difference is formed as a fraction of the reference cycle duration by selecting an output of the second shift register corresponding to a preselected stage thereof.
摘要:
A method for error processing in electronic controllers, particularly, in motor vehicles, is provided whereby errors determined on each vehicle start are permanently written in an error memory. On repeated recognition of similar errors, an error counter, provided for the error, is increased. In the case where it is determined that the error counter has reached a pre-determined state on a renewed vehicle start, a special “poor maintenance” is launched, which only permits the start of the monitored function when further tests are carried out and completed.
摘要:
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. However, if an error of the second kind is stored in the error memory, the switch-on control unit will keep the warning light on until the vehicle is traveling above the predetermined minimum speed and no new errors of the first or second kind are detected by the testing device.
摘要:
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).