Nissan Motor Company Limited

Hidetoshi Kanegae

Toshimi Abo

Masaharu Asano

Akio Hosaka

Seishi Yasuhara

Minoru Tomikashi

Masao Nakajima

Akira Hino

Masaaki Uchida

Kenji Masaki

Yoshihisa Kawamura

Katsunori Oshiage

Takashi Ueno

Akito Yamamoto

Shigeo Ishitani

An apparatus for analyzing control data for finding a cause of a trouble produced in a device controlled with a plurality of controlled variables. The apparatus includes sensors sensitive to a condition of the device for producing signals indicative of parameters reflective of the sensed condition. The parameter indicative signals are fed to a control circuit which calculates a valve corresponding to a setting of each of the controlled variables from a desired relationship. The calculated values are stored in time sequence along with the corresponding values of the parameter indicative signals. The stored values are transferred from the first memory to a second memory upon occurrence of a command signal indicating a trouble produced in the device. The transfer values are analyzed to find a cause of the trouble.

Trouble checking apparatus

A trouble checking apparatus for use with an automotive vehicle having sensors sensitive to a condition of the automotive vehicle for producing sensor signals indicative of parameters reflective of the sensed condition. The apparatus includes a control circuit responsive to the sensor signals for calculating a value corresponding to a setting of each of a plurality of means for controlling the automotive vehicle. A self-checking unit is connected to the control circuit for checking the sensor signals applied to the control circuit to provide a self-checking code indicative of a cause of automotive vehicle trouble when at least one of the sensor signals has an abnormal value. An external trouble checking unit is connected through a detachable connector to the self-checking unit for utilizing the sensor signals fed to the control circuit and the self-checking code to find a cause of automotive vehicle trouble.

Automotive vehicle trouble checking apparatus

A fail-safe system for an engine control system is capable of performing a fail-safe operation when a crank angle sensor fails. When the crank angle sensor malfunctions, at least one of a crank reference signal and a crank position signal will be absent. The fail-safe system prevents the engine from stalling even when one of the crank reference signal and the crank position signal is absent. The fail-safe operation will be carried out when the absence of the crank reference signal and/or the crank position signal is detected. In the fail-safe operation, a fail-safe signal is produced for controlling engine operation as a replacement for an engine control signal from the engine control system under normal conditions. The signal value of the fail-safe signal may be variable in accordance with an engine operating condition derived from an engine control parameter other than the crank angle sensor signals.

Fail-safe system for automotive engine control system for fail-safe

A failsafe system for an engine-control servomotor compares a servomotor command signal to a feedback signal from the servomotor. When the magnitude of the difference between the two signals is greater than a predetermined value for a predetermined time, the failsafe system shuts down the servomotor or performs some other engine shut-down procedure. The failsafe system includes a comparator for comparing the two signals, the output of which leads to two other op-amp-type comparators connected in parallel, which work on negative or positive outputs of the first-mentioned comparator, respectively. Each of the later comparators receives a reference voltage input against which to compare the output of the first-mentioned comparator. Their outputs lead parallelly to time-delay circuits which check for a positive output for a predetermined length of time by a well-known capacitor-integration technique.

Failsafe for an engine control

A start-up failsafe system for an engine control system monitors a command signal and the corresponding feedback signal for a fuel injection rate control servo device when the starter motor switch is closed. If the feedback signal and the command signal differ by more than a predetermined amount, the failsafe system acts to prevent operation of the starter motor.

An air-fuel ratio control system is disclosed for controlling the air-fuel ratio of a mixture supplied to an engine on one side of stoichiometric. The system comprises a sensor for detecting the arrival of the inlet air-fuel ratio at its stoichiometric level and fuel supply means for supplying a controlled amount of fuel to the intake system of the engine. Control means is associated with the sensor for providing first and second control signals to the fuel supply means so as to control the amount of fuel supplied therethrough. The first control signal occurs to cause the inlet air-fuel ratio to vary toward the stoichiometric level and the second signal occurs for a predetermined period of time after the inlet air-fuel ratio arrives at the stoichiometric level to cause the inlet air-fuel ratio to vary away from the stoichiometric level.

Air-fuel ratio control system for internal combustion engines

A fuel control system for a dual-shaft gas turbine engine having a gasifier turbine and a power turbine comprises a device for supplying fuel to a combustor of the engine by an amount necessary for engine ignition during engine starting. Under normal operating conditions, fuel is supplied to the combustor by a closed loop controller. An accelerating device increases the fuel supply to the combustor as time progresses from a first time when engine ignition takes place to a second time when the closed loop control of fuel supply takes place, thereby shortening the time period required for the engine to reach normal operation.

Fuel control system for gas turbine engine

To shorten the time length of a start phase of the operation of a two-shaft gas turbine engine, closed-loop control of the rate of fuel feed is performed based on the magnitude of deviation of actual rate of rotation of the gas generator shaft from a target value during a time period shortly after starting of the engine, until actual speed of the power turbine sufficiently nears a target value, and then the basis of closed-loop control is switched over to the magnitude of deviation of actual speed of the power turbine from the target value. This method is practised by appropriately presetting the target value of the rotation rate of the gas generator shaft and by continuously making a comparison between the aforementioned two deviations and always selecting the smaller one of the two for use it as a feedback signal to produce a fuel feed rate control signal.

Two-shaft gas turbine engine

Disclosed is a device useful for detection of air/fuel ratio of an air-fuel mixture subjected to combustion in a combustor by sensing oxygen in the exhaust gas, using a solid electrolyte concentration cell type oxygen-sensitive element which requires supply of a DC current to flow through its solid electrolyte layer between reference and measurement electrode layers to establish a reference oxygen partial pressure at the interface between the reference electrode and the solid electrolyte. The device comprises a control circuit to vary the intensity of the current for the oxygen-sensitive element in dependence on the magnitude of output voltage of the oxygen-sensitive element at least when a predetermined one of said output voltage and a reference voltage is higher than the other in order to compensate variations of the magnitude of the reference oxygen partial pressure caused mainly by variations of the temperature.

Oxygen sensing device having means for control of current to produce

A control system is disclosed which includes a digital microcomputer adapted to perform routines for controlling various operating parameters for an internal combustion engine. The system includes at least one switch adapted to detect a specified engine operating condition. Means are provided for causing the microcomputer to perform a routine required for the specified engine operating condition when the time of continuous occurrence of the specified condition exceeds a predetermined value.

Control system for internal combustion engines

A fuel injection valve of an internal combustion engine is opened at a predetermined crank angle position. A counter starts to count pulses from a clock pulse signal generator at the predetermined crank angle position, and produces a signal to close the fuel injection valve when the accumulated count in the counter reaches an integer value which corresponds to the ratio of Ti to Tc where Ti is the fuel injection time duration, calculated by a calculating means from engine operational parameters, and Tc is the period of the signal from the clock pulse signal generator. The clock pulse signal generator is controlled by the calculating means, and the period Tc of its output signal is thereby varied. The ratio of Ti to Tc should preferably be selected so as to be as close to the capacity of the counter as possible. A voltage controlled oscillator may be used as the clock pulse signal generator, together with a digital to analog converter which converts the fuel injection time interval Ti to a voltage value which is inputted to the voltage controlled oscillator so as to control its output frequency.

Fuel injection control system for an internal combustion engine

A gas turbine control system with a control signal generator for a two-shaft gas turbine having a compressor turbine and a power turbine. The gas turbine control system comprises, in combination, a control signal generator for outputting signals for giving optimum fuel supply rates to the fuel control valve in accordance with gas generator shaft speeds of the compressor turbine until the power turbine speed approaches a target power turbine speed, so that the turbine system can be controlled under direct control conditions, a comparator for outputting a signal to switch the system from direct control to feedback control when the signal level under the feedback control becomes smaller than that under the direct control, and a selector for selecting one of the above-mentioned two control conditions, in addition to a conventional feedback control system having a power turbine differential speed detector and an calculation unit.

Fuel control system for a gas turbine

Actual signals from various sensors which sense the operational state of an internal combustion engine, or dummy signals from a dummy signal generator, are selectively supplied to a control unit. This unit calculates from the actual or dummy signals and outputs control signals which are then selectively supplied to actual loads, such as actuators, or dummy loads, thereby determining the control signals under respective conditions.

Apparatus for testing a control system for automotive vehicle

An internal combustion engine self-testing control system has a microcomputer, which includes a memory unit pre-programmed with a program for testing the microcomputer. The system is so programmed as to be able to test itself by using an indicator to show the system state before controlling actuators that affect the engine operating values. That is, since it is impossible to test the system merely by observing the indicator states produced by the system, one or more test processes are added before controlling the actual engine operating values. In one example, the test timing is controlled by a power signal generated when the power supply is turned on, a start signal is generated when a starting switch is turned on (while the engine is being cranked), and a revolution indicating signal is generated when the engine is rotating. In this case, the checking is carried out somewhere in the interval between instigating of the power signal and the end of start signal, between the beginning of the start signal and the end of the start signal, or somewhere between instigation of the power signal and the beginning of the start signal, etc. Therefore, by observing the indicator states in the system whenever the power switch and the starting switch are turned on, it is possible to readily test the control system for an internal combustion engine.

Self-testing control system for an internal combustion engine

When the rate of increase of the load on a gas turbine with time is higher than a reference value, the amount of fuel supplied to the turbine is temporarily increased whereas, when the rate of decrease of the load with time is higher than a certain predetermined value, the amount of fuel supplied to the turbine is temporarily decreased. However, for a certain predetermined time interval after this decreasing of the fuel amount has ended, an increase in the amount of fuel supplied to the turbine is suppressed to a minimum even if the load on the gas turbine increases.

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Yokohama, Japan

Hidetoshi Kanegae