| CPC B62D 5/0484 (2013.01) [B62D 5/04 (2013.01); B62D 5/046 (2013.01); B62D 5/0481 (2013.01); H02J 9/06 (2013.01); H02P 23/00 (2013.01)] | 4 Claims |
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1. A vehicle power supply system for a vehicle equipped with a first power source and a steering device having a motor, the vehicle power supply system comprising:
a power source control unit having a second power source; and
a steering control unit that is connected to the first power source through the power source control unit and that controls the steering device, wherein:
the steering control unit includes a steering control microcomputer configured to control operation of the motor, the steering control microcomputer including a driving circuit that drives so as to supply the motor with electricity that is supplied as the driving circuit is connected to at least one of the first power source and the second power source, the steering control microcomputer being configured to control operation of the motor by controlling driving of the driving circuit;
the power source control unit includes a power source control microcomputer that switches a connection state of the driving circuit between (i) a first state in which electricity is supplied from the first power source to the driving circuit, and (ii) a second state in which electricity is supplied from the second power source to the driving circuit, the power source control microcomputer being configured to execute (a) a state detection process of detecting a state change of the first power source and (b) a switching process of switching the connection state;
the switching process includes:
a first switching process of switching the connection state to transition from the first state to the second state when an abnormality of the first power source is detected through the state detection process; and
a second switching process of, when having previously transitioned to the second state as a result of the abnormality of the first power source having been detected, switching the connection state to transition from the second state to the first state when recovery of the first power source from the abnormality is detected through the state detection process;
the steering control microcomputer is configured to, after the abnormality of the first power source has been detected, set an output-limited state for limiting a torque that the motor is able to output compared with the torque before the abnormality was detected;
the steering control microcomputer is configured to cancel the output-limited state upon completion of the second switching process;
the state detection process includes:
an abnormality condition determination process of determining that an abnormality condition of the first power source exists when an output voltage of the first power source is less than a voltage threshold value;
an abnormality resolution condition determination process of determining, after determining that the abnormality condition exists, whether an abnormality resolution condition is met, the abnormality resolution condition being met when the abnormality condition no longer exists; and
a recovery condition determination process of determining, after the abnormality resolution condition has been met, whether a recovery condition indicating that the first power source has recovered from the abnormality exists, the recovery condition being that an elapsed time from when the abnormality resolution condition has been met is equal to or greater than a time threshold value; and
the power source control microcomputer is configured (1) to execute the abnormality resolution condition determination process during a period between a time at which the abnormality condition has been determined to exist until a time limit elapses without the recovery condition being determined to exist, and (2) to not execute the abnormality resolution condition determination process after the time limit elapses.
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