Robert Boschgmbh

Winfried Klotzner

Rolf Daumer

Edmund Jeenicke

Manfred Schenk

Uwe Kiencke

Ulrich Flaig

Immanuel Krauter

Martin Zechnall

Ingo Gorille

Ernst-Olav Pagel

Wolfgang Borst

Wolfgang Busse

Hans-Christoph Du Mont

Karl Ott

Alfred Schulz

Gunter Honig

Heinz Moller

Gunther Kaiser

Peter Dilger

Hermann Vetter

Clemens Meichle

Cylinder recognition apparatus for a distributorless ignition system

The resistance to supply voltage, e.g. battery, fluctuation of an input/output circuit for a control system, e.g. vehicular ignition/fuel injection system, is improved by placing a comparator K in each analog input line, and using a voltage divider UD to compensate the reference voltage U.sub.R applied to one of the comparator inputs. Processing speed is increased by using digital comparators 22-26, which test not only for threshold value equal to counter state, but also for threshold value greater than counter state, in the duty-cycle modification circuit. Chip count is reduced and integration is increased by using a single voltage divider to supply all the input comparators and by using a High-Speed Output (HSO) port on the central processing unit (CPU) to perform multiple output tasks.

Vehicle control system with HSO-triggered output

An apparatus including a computer for generating a time duration signal is proposed, intended in particular for controlling fuel metering or ignition processes in internal combustion engines, wherein the time duration signal is formed in accordance with the formula

Apparatus for generating a time duration signal

The destination of commands provided by a microcomputer to an input-output unit over a data bus is provided without an address bus, while a control circuit in the input-output unit is connected with the microcomputer by connections for only three binary signals in one direction, 'clear', chip-select and data strobe and one in the other, namely interrupt. The control circuit has a decoder connected to the data bus that sorts out the commands, feeding the outputs through a gate array that are enabled by the chip-select and data strobe signals for timing. Commands for switching, such as beginning and ending counts, and so on are one-byte commands directly transmitted to the appropriate circuits of the input-output. Read and write commands are two-byte commands sequenced by a sequencing and lockout circuit, the circuit selected in first byte being activated to read or write to or from the data bus in the second byte while the decoder is blocked. The direction of transmission of the data bus is controlled over a single connection from the control circuit in accordance with whether a write command is or is not present.

Microcomputer system with input/output unit connected to the remainder

To reduce the data processing requirements within operating cycles of an automotive-type microprocessor or computer, the input/output unit has an angle increment counter receiving angle increment signals synchronized with rotation of the crankshaft of the engine, the counter providing output signals to comparators which, when the count state reaches predetermined values as applied from a data bus, derived from the microprocessor, to the comparator, then provides output signals to control the engine, for example by providing ignition control output signals, fuel injection control output signals, or the like. To further simplify computational tasks of the microprocessor, the input/output unit contains a timing element, for example a counter, which can provide variable timing intervals, for example by controlling the clock rate of the counter or a count number, under control of the data bus, and a transfer switch which selectively applies to a further counter either the signals from the timing circuit or from the crankshaft angle increment counter so that, as desired, data then being processed in the microprocessor can be selectively based on or compared with engine speed, or predetermined timing intervals, for consequential control of other operating parameters of the engine and the entire power train system of which it is a part.

Control system for an operating event in a vehicular power train

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.

Frequency-voltage and voltage-frequency converters

An input-output unit carries out some of the operations previously carried out in the microcomputer controlling the ignition, injection, etc. processes so that the number of bits in the microprocessor can be reduced. The input-output unit includes a counter which furnishes speed-dependent or angle-dependent signals. During a predetermined angle of rotation or while a particular speed-dependent value is counted and down, a frequency proportional to the quantity of air in the air inlet is counted, the resultant air number transferred to the microprocessor where it is modified. The modified air number can be counted down in the same counter which was used to count down the speed-dependent signals. The time required for counting down the modified air number determines the injection time and/or the closing time for an electronic switch in the primary circuit of the ignition coil. When the angle-dependent signal is used, a further counter counts down the air number several times, each time generating an interrupt signal. The latter count is in the microprocessor and when a predetermined number has been received, the microprocessor furnishes a terminate signal ending the controlled process.

Input-output unit for microprocessor controlled ignition or injection

To control the ignition timing in a multicylinder engine, the computer output signal which controls the current flow through the ignition coil for generating the spark in the first cylinder is delayed and then applied to the ignition coil controlling the spark in a subsequent cylinder. The computer output signal is delayed by passing through a shift register whose clock input is derived from a pulse generator generating a pulse for each predetermined incremental angular rotation of the crankshaft. If a single ignition coil and a distributor are used, the computer output signal and the delayed computer output signal are applied to an OR gate whose output controls a switch controlling the current through the ignition coil. When more than one ignition coil is used, the computer output signal is applied to a switch controlling the current through the first coil, the delayed computer output signal to a switch controlling the current to a second coil. Further delays may be furnished for a control of sparking in additional cylinders.

Simplified computer ignition control system

Repetitive operations, such as fuel injection and/or ignition timing of a gasoline engine, are controlled by a microprocessor with reference to engine operation parameters that provide electrical inputs in a manner achieving increased efficiency and economy by the provision of an input-output unit that supplies considerable preprocessing of the input signals under control of the microprocessor through the usual data and address buses. Counters are operated to count down from count limit values. The counting rate, as well as the count limit values, are capable of being varied by commands through the data bus, from time to time, so as to make the capabilities of the system adaptable to a wide variety of particular engines. The system is readily programmable for a particular application or machine if a programmable read-only memory (PROM or EPROM) is used for programming the microprocessor.

Input-output unit for a microprocessor engine control system

A fuel injection system receives valve control pulses, the length of which determines the fuel quantity delivered to the engine. A first counter receives a pulse train whose frequency depends on the air flow rate and this pulse train is admitted for a period defined by the engine speed. The content of the counter is then counted out at a frequency which is synthesized from operational parameters of the engine, including, in particular, the temperature. For this purpose, there is generated a temperature-dependent frequency which is fed to a multiplier circuit which combines this frequency with data derived from a memory to generate an output signal which is further processed to provide the fuel injection pulses for the engine.

Apparatus for determining the duration of fuel injection control pulses

A fuel injection apparatus for internal combustion engines, having a digital control apparatus for producing an actuating electrical signal for the engine injection valves proportional to the engine speed and the quantity of air aspirated by the engine, and a signal correction apparatus for modulating the injection actuating pulse in accordance with other parameters of the engine, such as fuel enrichment during starting or warmup of the engine, adjustment for idle, partial load, and full load conditions, and adjustment for the air-fuel ratio for both short time variable conditions, and long time variations such as variations in barometric pressure. This correction apparatus includes auxiliary storage register, interconnected to numerical frequency converters, which produce the correction signal from the information stored in the auxiliary storage registers.

Fuel injection apparatus for internal combustion engines

A central digital memory contains data relating values of operational variables of an installation to values of a stored parameter. The central memory is addressed in parallel via input lines carrying the address of the stored data. The address is generated by selecting one of several discrete input lines leading to an address selector memory which contains preliminary addresses related to the various operational states of the installation. A portion of the preliminary address is delivered directly to the central memory whereas another portion is used to preset a counter. If the particular operational state is dependent on another parameter, for example temperature, a temperature-dependent clocking frequency is admitted to the counter and alters its contents which are then used to supplement the first portion of the address already delivered to the central memory. If no temperature dependency exists, the second portion of the address is passed on without change.

Method and apparatus for addressing a digital memory

Operating parameters, such as speed and loading of the engine are converted in electrical signals which are converted into pulse rates, to control counting of an address counter, addressing a read-only (ROM) memory in which characteristics of the engine are stored. To provide easy introduction of additional parameters such as temperature, idle condition, maximum speed, start condition, etc., the final value of an accumulator counter, the number of which at a given time controls the ignition timing, can be changed; further, to simplify the system, the speed and load signals are processed during a portion of the time between successive ignition events, the remaining portion of the time being controlled solely by one of the parameters (preferably speed), thus simplifying the circuitry by providing a transfer switch connecting for the remaining period only the selected (preferably speed) signal to the accumulator counter, the count state of which controls the ignition instant.

Growing community of inventors

Maulbronn, Germany

Winfried Klotzner