Nippondenso Co., Ltd.

Toyota Jidosha Kogyo Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Yuji Hirabayashi

Susumu Akiyama

Katsunori Ito

Yoshihisa Sato

Takao Saito

Kenzo Ito

Takahide Kawamura

Hiroyasu Fukaya

Katsuhiro Ina

Haruhiko Ogiso

Atsushi Suzuki

Masakazu Ninomiya

Kazuaki Minami

Tetsuo Tanigawa

Hidemichi Tanabe

Mitsunori Takao

Norio Omori

Naoki Maeda

Kazushi Akutsu

Takahiko Kimura

Kiyohumi Kage

Katsonori Ito

A communication system includes a plurality of separate transmission units. A common signal line connects the units. A token is transferred from a first of the units to a second of the units during one sequence. The token is a right to output data to the common signal line. When the token is rejected by the second unit, the token is retransferred from the first unit at maximum a predetermined number of times during that sequence to the second unit. When the retransferred token is rejected by the second unit, the token may be transferred from the first unit to a third of the units during that sequence. In a next sequence, said predetermined maximum number of times said token is retransmitted to said second unit is then reduced.

Communication system

A plurality of control units are connected via a common signal line through which they communicate. Each control unit is operative to control an apparatus according to certain information the control unit normally receives directly through an exclusive signal line by operation of a directly-inputting device. A check is made to determine whether the directly-inputting device is operating normally. If not, then the required information is inputted from its source indirectly through another control unit by way of the common signal line.

Communication control system

Control units are mutually connected by separate common signal lines. A data link is provided between the control units via a preselected one of the common signal lines. A check is made as to whether the preselected common signal line is operating normally or abnormally. When the preselected common signal line is operating abnormally, the preselected common signal line is replaced by another common signal line in the data link.

A plurality of control systems mounted on a vehicle such as an automobile, and provided for different controlled objects are respectively made of control computers. These control computers are linked by a common data bus. These computers exclusively execute, for example, an engine control, a transmission control, a brake control, a suspension control, and a auto drive control. The data bus is further connected to a diagnosis computer. Each control computer detects a signal from the sensor provided corresponding to each controlled object, and outputs the detect signal to the data bus. Each control computer executes the logical operation for its control on the basis of its detect signal and various data transferred to the data bus. The diagnosis computer supervises an operating state of each control system on the basis of the data transferred to the data bus. When an abnormality is detected, the diagnosis computer stores this data in a large-capacity memory, and displays the abnormality.

Overall diagnosis apparatus for vehicle-mounted control devices

A data network system for a vehicle having a plurality of separate and distinct control computers carrying out a predetermined control function of the vehicle and a data communication line for communicating data among the control computers. One of the control computers determines the number of the other computers which are linked with the data communication line, and in response to that number a data transfer rate output from each of the control computers to the data communication line is determined.

Network system for data communication in a vehicle

Sensors detect parameters. Control units control vehicle equipments in accordance with the detected parameters. In each of the control units, at least one of the detected parameters and internally produced data is converted into serial data as communication data, and serial data is converted into other form data. A transmission medium connects the control units via a serial data link. Serial interfaces are associated with the control units respectively. Each of the serial interfaces includes a connection terminal connected to the transmission medium, an input terminal and an output terminal both connected to the associated control unit. Each of the serial interfaces inputs serial data from the associated control unit via its input terminal and outputs the inputted data to the transmission medium via its connection terminal. Each of the serial interfaces inputs serial data from the transmission medium via its connection terminal and outputs the inputted data to the associated control unit via its output terminal.

Communication system for vehicle

Disclosed is an azimuth determination apparatus attached to a motor vehicle for determinating the forward direction of the vehicle. The azimuth determination apparatus includes an azimuth sensor for generating orthogonal first and second signals indicative of the forward direction of the vehicle. Two azimuth vectors are obtained on the basis of the orthogonal first and second component signals, first components of the two azimuth vectors being maximum and minimum. The determination is made in terms of the fact that the difference between second components of the two azimuth vectors is below a predetermined value. In accordance with the determination, the orthogonal first and second component signals are corrected on the basis of said two azimuth vectors so that the accurate moving direction of the motor vehicle can be obtained irrespective of the remanence of the vehicle.

Azimuth determination apparatus

An engine control method and apparatus generally applicable to those control systems of the engine such as an ignition system, fuel injection system, etc., which are controlled to optimum operation in accordance with the engine operating conditions. A plurality of angular pulses are generated during each rotation of the engine and these pulses are counted. In response to each pulse, an angular interrupt request is generated and the interrupt is performed in response thereto. The angular interrupt routines are of the highest priority and are executed irrespective of the execution status of the central processing unit to control an electric device associated with the engine in accordance with control data calculated by the central processing unit. Program interrupt requests are generated during selected angular interrupt routines when the counted number of angular pulses reaches a predetermined value. Program interrupt routines of lower priority than the angular interrupt routines are then executed to calculate the control data for the electric device.

Computer based engine control with lower priority interrupt requests

An engine control method generally applicable to those control systems of the engine such as an ignition system, fuel injection system, etc., which are controlled to optimum operation in accordance with engine operating conditions. Angular pulses are generated each time the output shaft of the engine rotates a predetermined angular amount. These angular pulses are counted from the occurrence of a position pulse which is generated at a predetermined angular position of the output shaft of the engine. A central processor is employed to calculate a first angular position at which an electric device for the engine is to be controlled. The central processor also calculates a time interval between the first angular position and a second angular position at which one of the angular pulses is to be provided just before the first angular position. When the angular pulse counting reaches a value corresponding to the second angular position, fixed frequency clock pulses are then counted. When the calculated required time interval has passed as determined by counting the fixed frequency clock pulses, the electric device is controlled.

Engine control event timing employing both crank angle rotation and time

In an air flow control apparatus for controlling an amount of air flow under control of a throttle valve in an engine, a sensor produces a first signal indicative of engine operation, and another sensor produces a second signal indicative of the atmospheric pressure. A microcomputer determines whether or not the first signal indicates an idling condition of the engine. If so, the microcomputer calculates, in dependence upon the first signal, a first parameter indicative of an amount of the air flow necessary for maintaining a desired idling condition of the engine. If not, the microcomputer calculates, in dependence upon the first signal, a second parameter indicative of an amount of the air flow related to loaded condition of the engine. Furthermore, the microcomputer calculates, in dependence upon the second signal, a third parameter indicative of an additional amount of the air flow related to the atmospheric pressure to compensate the second parameter and produces first and second output signals respectively indicative of the first and compensated second parameters. An electrically operated valve is responsive to the first and second output signals for controlling an amount of the air flow respectively related to idling and loaded conditions of the engine.

Air flow control apparatus for internal combustion engine

An engine control method generally applicable to those control systems of the engine such as an ignition system, fuel injection system, etc., which are controlled to optimum operation in accordance with the engine operating conditions. In this method, an operation starting timing and an operation ending timing of the control system, e.g., in the case of the ignition system, an ignition coil energization starting timing and an ignition timing (an energization ending timing) are computed at each of predetermined computing cycles, and the latest computed ignition timing, for example, which is computed after the coil energization has been started further taking into consideration of the actual coil energization timing and a minimum required energization period is compared with an ignition timing computed in the preceding computing cycle, and a corrective computation of the latest computed ignition timing is carried out depending on the result of the comparison to obtain an optimum ignition timing. Also the history of the ON-OFF state of a bleed valve in an engine air supply system is monitored. The actual duty cycle of the valve is compared with a desired duty cycle to determine whether or not to open the valve for a succeeding time period.

Method and apparatus for controlling the duty cycle of an off-on type

Spark ignition timing of an internal combustion engine is oscillated on each side of a variable reference setting by varying it at stepwisely variable amounts during positive and negative swings and the resultant engine speed is detected in at least three successive phases. The detected engine speed values are compared one against each other to determine whether they satisfy one of two specified conditions. The variable reference is adjusted in a direction toward an optimum position depending on which one of the conditions is satisfied.

Method and system for operating an internal combustion engine at optimum

Spark ignition timing of an internal combustion engine is oscillated on opposite sides of the setting of a variable reference timing and the resultant engine speed is detected in at least three successive phases of the oscillation and stored in respective memories. The contents of the memories are compared with each other to detect whether they establish one of two predetermined relationships which occur exclusively in the absence of a manual command input to the engine. The variable reference setting is adjusted by a predetermined amount in a specified direction in response to the established relationship. The process is repeated so that the reference setting approaches an optimum advance angle at which the engine output torque is at a maximum. When the reference setting is at or near the optimum point or when a manual command engine input is present, the registered engine speed values establish a relationship other than the predetermined ones and the reference setting is not adjusted.

Method and system for operating a power-producing machine at maximum

An engine control method and apparatus generally applicable to those control systems of the engine such as an ignition system, fuel injection system, etc., which are controlled to optimum operation in accordance with the engine operating conditions. In this method, an operation starting timing and an operation ending timing of the control system, e.g., in the case of the ignition system, an ignition coil energization starting timing and an ignition timing (an energization ending timing) are computed at each of predetermined computing cycles, and the latest computed ignition timing, for example, which is computed after the coil energization has been started, further taking into consideration the actual coil energization timing and a minimum required energization period is compared with an ignition timing computed in the preceding computing cycle, and a corrective computation of the latest computed ignition timing is carried out depending on the result of the comparison to obtain an optimum ignition timing.

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Aichi, Japan

Yuji Hirabayashi