Robert Boschgmbh

Peter Dilger

Gunter Honig

Helmut Kauff

Werner Nitschke

Edmund Jeenicke

Alfred Schulz

Winfried Klotzner

Wilfried Venzke

Heinrich Baumann

Klaus Glockler

Repetitive processes in internal combustion engines which are dependent upon the values of particular parameters are controlled either by a main computer or an auxiliary computer. Switching from the main to the auxiliary computer takes place if a sequence error detecting stage detects errors in the desired alternation between the main control signals furnished by the main computer and reference mark signals indicative of predetermined angular positions of a shaft of the engine. Specifically, the system is switched to operate under control of the auxiliary computer if such an alternation error occurs again within a predetermined number of cycles. The switching can also take place as a result of missing reference mark signals and as a result of the absence of monitoring signals indicative of correct operation of the main computer program.

Apparatus for detecting malfunction in cyclically repetitive processes

A fuel metering apparatus in an internal combustion engine is proposed, in which the metering signal is correctable in accordance with the mixture composition and/or the exhaust gas composition, this composition is detected by means of a sensor for at least one component of the mixture and/or exhaust gas, and the sensor signal proceeds to a single threshold switch for evaluation. The output level of the threshold switch is monitored in its course and the correction signal as well as an error recognition signal are derived from it.

Fuel metering apparatus in an internal combustion engine

An apparatus for controlling the current through an electromagnetic injection valve of an internal combustion engine during its pickup and holding phases by opening and closing a first switch connecting the valve to a voltage source. The first switch is initially closed by a valve timing circuit to initiate pickup of the valve. A first current-sensing resistor connected in series with the first switch produces a signal to open the first switch when the valve current attains an upper threshold value which assures valve pickup, and to close a second switch connected in series with a second current-sensing resistor across the valve. When the valve current drops to a lower threshold value greater than the valve drop-out current, the second current-sensing resistor produces a signal to reclose the first switch and open the second switch for a predetermined time, after which the first switch is again opened and the second switch closed. The cyclic opening and closing of these switches by the second current-sensing resistor continues until both switches are opened by the valve timing circuit. In another embodiment, the pickup time of the valve is determined by measuring the time for the valve current to increase to a predetermined value after it is first energized by the value timing circuit, and the valve holding time is adjusted in accordance with the valve pickup time, to assure correct fuel injection even when the voltage source is not maintained constant.

Apparatus for controlling the current through an electromagnetically

A nonlinear characteristic curve of a frequency-voltage converter is approximated by summing the outputs of energized ones of a plurality of either voltage or current sources. The current sources are energized and de-energized in accordance with information contained in storage elements which may, for example, be parts of a shift register, or of an addressable storage. The breaks in the characteristic curve are achieved by changing the number of energized current sources or the current supplied by at least some of the sources at time intervals Ti=1/fi, where fi are the break frequencies and where time is measured starting with the leading edge of each pulse of the pulse frequence having the frequency f.sub.x which is to be converted to a voltage. Voltage-frequency converters can be created by connecting the frequency-voltage converter into the feedback path of a converter circuit receiving a voltage U.sub.x and furnishing the frequency f.sub.x in response thereto.

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Neuried, Germany

Peter Dilger