Electronic control unit having hold circuit and method therefor
AssigneeDenso Corporation
InventorsTakashi Harada, Nobutomo Takagi, Noriaki Terashima, Yasuhiro Tanaka
Life of this patent
Estimating the term…
Abstract
When a microcomputer is automatically reset due to uncontrollable process and recovers from reset, a cancel pulse signal is outputted from the microcomputer to a hold circuit to stop supply of a driving current to a relay. This pulse is generated, when a predetermined condition indicative of possibility of battery rundown lasts for a predetermined time. The predetermined condition includes that a hold set condition is detected based on a status signal inputted from the hold circuit; a card key is present in a key slot; a key verification inputted from an immobilizer ECU is not available; a vehicle speed is zero; and an engine revolution is zero.
Claims19
An electronic control unit that receives information from external devices and outputs control signals to a controlled object, comprising:
- a microcomputer including;
- a state propriety determination means for making a determination on a propriety of a state of a control signal outputted to the controlled object based on information from the external devices, and
- a signal state control means for carrying out control so as to bring the control signal into appropriate state when the state of the control signal is determined inappropriate by the state propriety determination means;
- and
- a hold circuit that holds and changes a signal level of the control signal and outputs a state signal indicative of the signal level,
- wherein the microcomputer is constructed to produce a hold signal or a cancel signal to the hold circuit thereby to change the signal level of the control signal outputted to the controlled object, and
- wherein the microcomputer is constructed to detect the state of the control signal based on the state signal outputted from the hold circuit.
An electronic control unit comprising:
- a hold circuit which changes a signal level in response to an input of a trigger signal and holds the signal level;
- and
- a trigger signal generation circuit which generates the trigger signal when a preset number or more of pulses are inputted within a preset period,
- wherein:
- the pulse is applied from a microcomputer mounted in a vehicle, and
- the output of the hold circuit is used as a control signal for controlling a state of passage of current through power feeder lines provided in the vehicle.
A method of controlling an electric power supply in a vehicle having a microcomputer, a hold circuit and an electric power supply relay, the hold circuit holding a relay condition in response to a hold signal generated by the microcomputer, the method comprising:
- determining, based on a hold set signal generated from the hold circuit, whether the relay condition is held by the hold circuit;
- determining whether a vehicle speed and an engine speed are zero;
- and
- generating a cancel signal from the microcomputer to the hold circuit to thereby cancel the hold condition of the relay by the hold circuit, when the determining steps determine that the relay is in the hold set condition and the vehicle speed and the engine speed are zero.
An electronic control unit that receives information from external devices and outputs control signals to a controlled object, comprising:
- a microcomputer including;
- a state propriety determination means which makes determination on a propriety of a state of a control signal outputted to the controlled object based on information from the external devices, and
- a signal state control means which carries out control so as to bring the control signal into appropriate state when the state of the control signal is determined inappropriate by the state propriety determination means,
- wherein the state propriety determination means makes the determination periodically when the microcomputer is in sleep state.
An electronic control unit that receives information from external devices and outputs control signals to a controlled object, comprising:
- a microcomputer including;
- a state propriety determination means which makes determination on a propriety of a state of a control signal outputted to the controlled object based on information from the external devices, and
- a signal state control means which carries out control so as to bring the control signal into appropriate state when the state of the control signal is determined inappropriate by the state propriety determination means,
- wherein the number of the information used in the state propriety determination means to determine the state inappropriate is different between a sleep mode and a non-sleep mode of the microcomputer.
An electronic control unit that receives information from external devices and outputs control signals to a controlled object, comprising:
- a microcomputer including;
- a state propriety determination means which makes determination on a propriety of a state of a control signal outputted to the controlled object based on information from the external devices, and
- a signal state control means which carries out control so as to bring the control signal into appropriate state when the state of the control signal is determined inappropriate by the state propriety determination means,
- wherein the information includes at least one of a vehicle speed and an engine speed.
An electronic control unit comprising:
- a hold circuit which changes a signal level in response to an input of a trigger signal and holds the signal level;
- and
- a trigger signal generation circuit which generates the trigger signal when a preset number or more of pulses are inputted within a preset period,
- wherein:
- the trigger signal generation circuit includes a frequency/voltage conversion circuit including a capacitor charged by the pulse and a discharge circuit discharging the capacitor at a certain rate thereby generating the output signal having a signal level corresponding to a charging voltage of the capacitor, the frequency/voltage conversion circuit generating an output signal having a signal level corresponding to a pulse interval of the pulses, and
- the output signal from the frequency/voltage conversion circuit is used as the trigger signal.
Dependencies are inferred from the claim text.