Abstract: There is provided a communication device system and a card-type device, in which an attachable and detachable communication device can be attached later only when a control, maintenance or monitor function and an authentication function are required. A communication function, a function to convert an electric signal of a control object device into another communication protocol, and an encryption/decryption function are concentrated on one card, and this card is obtained only when necessary, and the control, maintenance or monitor can be performed remotely. The card is created by an appropriate certificate authority or a manufacture maker of the control object device, and necessary information can be set.

Abstract: There is provided a communication device system and a card-type device, in which an attachable and detachable communication device can be attached later only when a control, maintenance or monitor function and an authentication function are required. A communication function, a function to convert an electric signal of a control object device into another communication protocol, and an encryption/decryption function are concentrated on one card, and this card is obtained only when necessary, and the control, maintenance or monitor can be performed remotely. The card is created by an appropriate certificate authority or a manufacture maker of the control object device, and necessary information can be set.

Abstract: An electric steering control device is provided which is capable of enabling the driver to perform steering manipulation stably without being substantially affected by the ambient temperature and the heat generation of the control device. The control device comprises a temperature sensor for detecting the temperature of a circuit board mounting a motor drive circuit thereon and a compensation section for compensating an electric current command value based on the board temperature detected by the temperature sensor, so that en electric motor for exerting an assist force on a vehicle steering mechanism is driven by the compensated electric current command value output from a motor drive circuit. Therefore, the steering operation can be done stably without being substantially affected by the ambient temperature and the heat generation of the control device.

Abstract: In a neutral position detection error protecting apparatus, vehicle wheel velocities of right/left driven wheels are detected and a right/left wheel velocity difference is obtained. Then, when a right/left wheel velocity difference is less than a predetermined velocity a steering rotation angle is more than a predetermined value and a vehicle wheel velocity is more than a predetermined velocity in a predetermined period, it is determined that there is an abnormality in the vehicle wheel velocities.

Abstract: A variable gear ration system includes an actuator connected to a steering system of an automobile, a sensor for detecting a current angle of the actuator and a controller for executing a feedback control based on the current angle of the actuator and a target angle determined in accordance with a operational state including a steering angle of a steering wheel and a vehicle speed so that a output position of the actuator approach the target angle. The variable gear ration system varying a steering angle of a vehicle wheel relative to the steering angle of the steering wheel depending on a operational state. A feedback value of the current for feedback control is held at a start of a reverse operation of the steering wheel, from the start of the reverse operation of the steering wheel to a timing that the target angle and the current angle correspond each other when the actuator inferiorly follows a move of the steering wheel and the steering wheel is operated in reverse.

Abstract: An electric steering control device is provided which is capable of enabling the driver to perform steering manipulation stably without being substantially affected by the ambient temperature and the heat generation of the control device. The control d vice comprises a temperature sensor for detecting the temperature of a circuit board mounting a motor drive circuit thereon and a compensation section for compensating an electric current command value based on the board temperature detected by the temperature sensor, so that en electric motor for exerting an assist force on a vehicle steering mechanism is driven by the compensated electric current command value output from a motor drive circuit. Therefore, the steering operation can be done stably without being substantially affected by the ambient temperature and the heat generation of the control device.

Abstract: In a neutral position detection error protecting apparatus, vehicle wheel velocities SFR, SFL of right/left driven wheels FR, FL are detected by vehicle wheel sensors 27a, 27b and a right/left wheel velocity difference VFD is obtained from vehicle wheel velocities VFR, VFL of the driven wheels FR, FL through vehicle wheel velocity signal abnormality determining processing 30b so as to detect steering angle information &thgr;h from the steering wheel 21.