Abstract: A vehicle safety system is equipped with a microcomputer for reliably detecting whether or not programs for controlling activation of passenger protection devices are being properly executed and, based on this detection, preventing problems from occurring in the control operations of the programs. According to one aspect of the invention, the system monitors a program executed on an interrupt basis at prescribed regular time intervals, a repeatedly executed program, and the operations of these programs, synchronously with the execution of the programs, and resets the microcomputer if an error is detected in the execution of either program. According to another, at the time of moving to a subroutine a code peculiar to the subroutine is saved at the entry portion and the saved code is compared with the code peculiar to the executed subroutine at the exit portion for detecting occurrence of error and if error is detected the microcomputer is reset.

Abstract: A vehicle safety device control system includes a plurality of acceleration sensors. Test pulses are supplied to the plurality of acceleration sensors. In order to judge whether or not each acceleration sensor has failed each acceleration sensor is checked for whether or not it outputs a signal that corresponds to the test pulse. The signal from the failed acceleration sensor is not used when a determining if a collision has occurred; only the signals from the other acceleration sensors are used in this determination.

Abstract: A system for controlling an object such as a vehicle safety device comprises a microcomputer, and reset circuits. The microcomputer judges whether or not an identification data is stored in a specific area of the RAM in order to identify the kind of the resetting method. If the judgment result is "NO", the object is controlled after an early judgment of the control system is effected. In contrast, if the judgment result is "YES", the object is controlled without effecting the early checking.

Abstract: In a control apparatus that activates a preloader device and after a timing delay an air bag device when a vehicle collision is detected, the apparatus has a detector for detecting whether or not a seatbelt is buckled, and a timing signal for activating the air bag device is generated without the timing delay if the seatbelt is not buckled, whereby the air bag device can be activated with a timing appropriate to the condition present at the time.

Abstract: A control system for a vehicle safety device includes a drive circuit. The drive circuit includes a main switching element, and a safety switch which is turned on by an inertia force produced at the time of a collision of the vehicle. The vehicle safety device is activated when the main switching element and said safety switch are both turned on. The control system further includes an acceleration sensing circuit for detecting deceleration of the vehicle, and a microcomputer. The microcomputer judges, based on a deceleration signal from the acceleration sensing circuit, whether or not a collision has occurred, and outputs an ON-instruction signal to the main switching element when the microcomputer judges that the collision has occurred. The microcomputer also judges whether or not the acceleration sensing circuit is subjected to a malfunction, and judges whether the safety switch is in the ON state or the OFF state.

Abstract: A control system for a vehicle safety device includes an acceleration detecting device for detecting the deceleration of the vehicle, an integrating device for integrating the deceleration from the acceleration detecting device, a collision judgment device for comparing the integral value, obtained by the integrating device, with a trigger threshold level so as to judge whether or not a collision has occurred, and for outputting an activation instruction signal when the collision judgment device judges that the collision has occurred, and a drive circuit responsive to the activation instruction signal from the collision judgment device so as to activate the vehicle safety device. The control system further includes a deceleration compensation device for adjusting the trigger threshold level in accordance with the deceleration in such a manner that the trigger threshold level becomes low when the deceleration is large and that the trigger threshold level becomes high when the deceleration is small.

Abstract: A control system for a vehicle safety device includes a pair of acceleration sensing circuits. The outputs of the acceleration sensing circuits correspond to a deceleration of the vehicle in a direction of running of a vehicle, and are in opposite phase with each other. A differential calculation device effects calculation in accordance with the difference between the outputs of the acceleration sensing circuits, so as to cause noises, applied to the acceleration sensing circuits, to cancel each other, thereby preventing an inadvertent activation of the vehicle safety device due to such noises.