Hitachi, Ltd.

Takeshi Hirayama

Shigeru Oho

Fumio Hamano

Matsuo Amano

Akira Hasegawa

Takao Sasayama

Shinichi Sakamoto

Masahiro Matsumoto

Takanori Shibata

Masami Shida

Masahide Sakamoto

Shirou Baba

Yoshinori Sato

Kazuo Kato

Hideo Nakamura

Takashi Sase

Masayuki Miki

Shigeo Kuboki

Shigeaki Yoshida

Kazuo Katoh

Masami Shiida

In a data transmission system having a data processing unit (MPU) and a communication control unit (CIM) and capable of transmitting a data to a local control unit (LCU) in a half duplex mode, the data processing unit receives the data by an interruption based on an end of data reception signal supplied from the communication control unit.

Data transmission system having a communication control computer for

A collective wiring system for an automobile provides a central control unit which communicates with a plurality of terminal control units each connected to one or more input or output devices, such as switches, sensors, motors and the like. The control over output devices in response to the status of input devices is performed by the central control unit on the basis of tables of data stored in memory. A scan table controls the order in which data communications are made to the terminal control units to obtain their status and provide them with control commands. A monitor table stores the current status of the terminal control units and a control table stores the control data for the terminal control units. A connection table stores the relationship between the terminal control unit for an input device and the terminal control unit for the output device to be controlled thereby. Thus, connection control between input and output devices is effected by software.

Collective wiring system and method of control thereof

Data transmission system

In a data transmission system having a central control unit including a data processing unit (MPU) and a communication control unit (CIM) which is capable of transmitting data to a local control unit (LCU) in a half duplex mode, the data processing unit receives the data in an interruption based on an end of data reception signal supplied from the communication control unit. At the time of initialization of the system, the central control unit responds to the application of power to the system by transmitting predetermined control data to the local control unit to set the state of accessory devices connected thereto, thereby preventing improper operation of the accessory devices during system startup.

Control method for a collective wiring system

A novel method of controlling air-fuel ratio for an internal combustion engine is disclosed, which comprises a memory area for holding regional compensation factors used for air-fuel ratio control, a memory area for holding new regional compensation factors obtained by learning, and a memory area for holding regional compensation factors based on the result of the learning immediately before the latest learning, thus rationalizing the new setting and updating proceses of regional compensation factors according to the result of learning.

Method of controlling air-fuel ratio

A terminal device for a multiplexed data transmission system has a decoder matrix having plural groups of function setting inputs for selecting plural types of functions such as interface, operation modes and other. One group of the function setting inputs are preferably address designating signals which are utilized for determining the interface. The other group of the function setting inputs determines various additional functions such as, for example, enabling/disabling of fail-safe function and automatic transmission function. Selection with the aid of the matrix allows selection of a large number of functions with a small number of input signals. Utilization of the address signals to this end allows the number of terminal pins to be decreased to a minimum.

Terminal for data transmission system

A novel method of controlling air-fuel ratio for an internal combustion engine is disclosed, which comprises a memory area for holding regional compensation factors used for air-fuel ratio control, a memory area for holding new regional compensation factors obtained by learning, and a memory area for holding regional compensation factors based on the result of the learning immediately before the latest learning, thus rationalizing the new setting and updating processes of regional compensation factors according to the result of learning.

Method controlling air-fuel ratio

A terminal device for outputting control signals and receiving sensor outputs is equipped with address setting terminals for setting an address of the terminal device. The address information at the address setting terminals is supplied to a decoder which decodes an input/output function or mode setting signal. Input/output functions of input/output terminals are set by the address information by controlling output buffer circuits which transmit the signals of the input/output terminals, in accordance with the decoded input/output function setting signal. The address setting terminals are shared by the address terminals and the input/output function setting terminals to that the number of terminals can be reduced.

Information transmission system

A method of testing a successive comparison type analog/digital converter which incorporates a voltage comparator, a register for successive comparison and a digital/analog converter. A reference digital signal is inputted to the incorporated digital/analog comparator to be converted into an analog signal, while a digital signal corresponding to the reference digital signal is inputted to an externally provided reference digital/analog converter to be converted into an analog signal. Both analog signals thus produced are compared with each other through the incorporated voltage comparator to thereby determine conversion accuracy. A successive comparison type analog/digital converter suited for the test includes further a change-over switch for introducing the externally supplied digital signal to the incorporated digital/analog converter and a changeover switch for leading outwardly the output signal from the voltage comparator.

Method of testing analog/digital converter and structure of

An engine control apparatus includes a microprocessor, a ROM for holding a program required for the operation of the microprocessor, and a RAM for holding data supplied from the microprocessor. Pulse signals representative of results of the arithmetic operations executed by the arithmetic unit on the basis of input signals available from various sensors as well as data stored in the memory in accordance with the program are supplied to actuators for controlling engine operations through an input/output circuit. The control apparatus further includes a counter for counting crank angle pulses produced in synchronism with rotation of the engine shaft, an interrupt request generating circuit for requiring an interrupt to the microprocessor when overflow occurs in the counter. In response to every interrupt request, the microprocessor causes the count value held in the RAM to be incremented by unity. After elapse of a period for measuring the rotational speed of the engine, the count value held in the counter of the input/output circuit is corrected by the number of overflows held in the RAM.

Electronic control apparatus for an internal combustion engine

In an electronic control apparatus for an internal combustion engine, the contents of a selected reference register are compared with the count contents of a timer so that when equality is found therebetween, an interrupt signal is applied to a central processing unit, which then computes when and how a control condition is to be changed with respect to one of a plurality of controlled systems and the contents of the reference register are updated accordingly. In addition, a plurality of actuators for controlling the operation of the engine are selectively controlled in accordance with control signals generated from the central processing unit on the basis of the receipt of the interrupt signals.

Electronic control apparatus for internal combustion engine

An information transmitting apparatus includes a transmitting apparatus for transmitting control information; a receiving apparatus for receiving the control information; a transmission line provided between the transmitting apparatus and the receiving apparatus; and a load which operates in response to the output of the receiving apparatus; wherein the transmitting apparatus transmits the control information through the transmission line to the receiving apparatus within a given time period and the receiving apparatus makes the load operative on the basis of the control information received. The receiving apparatus has a circuit for detecting the reception interval of the transmission information from the transmission line and for generating an abnormality signal when that interval becomes a predetermined time or more.

Information transmitting apparatus

A method of controlling fuel supplied to an engine comprises the steps of computing the quantity of air taken into the engine on the basis of the output from an air flow rate sensor, integrating the quantity of intake air computed in the first step, determining the level for setting the period of generation of a fuel-quantity control pulse signal from a pulse generating circuit on the basis of the output from an exhaust gas sensor, and generating pulses of predetermined pulse width from the pulse generating circuit when a predetermined relation is attained between the level determined in the third step and the result of integration in the second step.

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Mito, Japan

Takeshi Hirayama