Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of the invention:
[0001] The present invention relates to an algorithm for detection of disconnection of redundant power supply, and more specifically to the algorithm for detection of disconnection of redundant power supply to an engine control unit.

Background of the invention:
[0002] US 2004124705 AA describes an engine control unit for a car. The line of a control signal from the central processing unit is in an unexpected abnormal state though the ignition is off, cannot move the power source IC into the non-operation state and the battery is consumed. An object of the present invention is to provide a control unit for stopping supply of the constant voltage into the engine control unit even in such a case and preventing the battery from consumption. A delay circuit for delaying an ignition OFF signal is installed outside the central processing unit and by controlling the power source IC to OFF by an output signal of the delay circuit or by the delay circuit for delaying by a longer time than that of a shut-off signal from the CPU due to the ignition OFF signal, and by the AND circuit of the output signal of the delay circuit and the shut-off signal from the CPU, and by an output signal of the AND circuit which is changed from high to low, the power supply from the power source IC is stopped.

Brief description of the accompanying drawing:
[0003] An embodiment of the disclosure is described with reference to the following accompanying drawing:

[0004] FIG. 1 illustrates a flow chart for detection of disconnection of redundant power supply to an engine control unit in one embodiment of the invention.

Detailed description of the embodiments:
[0005] FIG. 1 illustrates an algorithm 100 for detection of disconnection of redundant power supply to an engine control unit. The algorithm 100 comprises supplying 110 electric power from an electric battery to a ground terminal of the engine control unit via a first electronic flow path that is in electronic communication with a first electronic switch, and supplying 120 electric power from the electric battery to the ground terminal of the engine control unit via a second electronic flow path that is in electronic communication with a second electronic switch. The algorithm 100 further comprises connecting 130 a third electronic flow path between the first electronic flow path and a capacitor bank of the electronic control unit, supplying 140 electric power from the first electronic flow path to the capacitor bank of the electronic control unit, and connecting 150 a fourth electronic flow path between the second electronic flow path and the capacitor bank of the electronic control unit. The algorithm 100 further comprises supplying 160 electric power from the second electronic flow path to the capacitor bank of the electronic control unit, disengaging 170 the second electronic switch by the electronic control unit, and measuring 180 a voltage drop between the capacitor bank of the engine control unit and the ground terminal of the engine control unit by the engine control unit, and inferring 190 that the first electronic flow path is not functional if the voltage drop between the capacitor bank of the engine control unit and the ground terminal of the engine control unit decreases at a rate that is above a user defined threshold rate.

[0006] FIG. 1 illustrates an algorithm 100 for detection of disconnection of redundant power supply to an engine control unit. The algorithm 100 comprises supplying 110 electric power from an electric battery to a ground terminal of the engine control unit via a first electronic flow path. More specifically, the first electronic switch is in electronic communication with the first electronic flow path and controls the flow of electric power from the electric battery to the ground terminal of the electronic control unit. When the first electronic switch is in a disengaged position, electric power does not flow from the battery to the ground terminal of the electronic control unit via the first switch. However, when the first electronic switch is in an engaged position, electric power flows from the electric battery to the ground terminal of the electronic control unit via the first electronic switch. The algorithm 100 for detection of disconnection of redundant power supply to the engine control unit further comprises supplying 120 electric power from the electric battery to the ground terminal of the engine control unit via a second electronic flow path. More specifically, the second electronic switch is in electronic communication with the second electronic flow path and controls the flow of electric power from the electric battery to the ground terminal of the electronic control unit. When the second electronic switch is in a disengaged position, electric power does not flow from the electric battery to the ground terminal of the electronic control unit via the second switch. However, when the second electronic switch is in an engaged position, electric power flows from the electric battery to the ground terminal of the electronic control unit via the second electronic switch.

[0007] In an exemplary embodiment, the algorithm 100 further comprises connecting 130 a third electronic flow path between the first electronic flow path and a capacitor bank of the electronic control unit. The third electronic flow path facilitates supplying 140 electric power from the first electronic flow path to the capacitor bank of the electronic control unit. The algorithm 100 further comprises connecting 150 a fourth electronic flow path between the second electronic flow path and the capacitor bank of the electronic control unit. The fourth electronic flow path facilitates supplying 160 electric power from the second electronic flow path to the capacitor bank of the electronic control unit. The algorithm 100 further comprises disengaging 170 the second electronic switch by the electronic control unit. Once the second electronic switch is disengaged by the electronic control unit, a voltage drop between the terminals of the capacitor bank (240 and 250) of the engine control unit is measured 180 by the engine control unit. If the voltage drop between the terminals of the capacitor bank (240 and 250) of the engine control unit decreases at a rate that is above a user defined threshold rate and/or reaches a defined threshold voltage value, it is thereby inferred 190 by the electronic control unit that the first electronic flow path is not functional.

[0008] The algorithm further comprises disengaging 200 the first electronic switch by the electronic control unit. Once the first electronic switch is disengaged by the electronic control unit, a voltage drop between the terminals of the capacitor bank (240 and 250) of the engine control unit and the ground terminal of the engine control unit is measured 180 by the engine control unit. If the voltage drop between the terminals of the capacitor bank (240 and 250) of the engine control unit and the ground terminal of the engine control unit decreases at a rate that is above a user defined threshold rate and/or reaches a defined threshold voltage value, it is thereby inferred 190 by the electronic control unit that the second electronic flow path is not functional.

[0009] It should be understood that the embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.

, Claims:We claim:

1. An algorithm (100) for detection of disconnection of redundant power supply to an engine control unit, the algorithm (100) comprising:
supplying (110) electric power from an electric battery to a ground terminal of said engine control unit via a first electronic flow path that is in electronic communication with a first electronic switch;
supplying (120) electric power from said electric battery to said ground terminal of said engine control unit via a second electronic flow path that is in electronic communication with a second electronic switch;
connecting (130) a third electronic flow path between the first electronic flow path and a capacitor bank of said electronic control unit;
supplying (140) electric power from the first electronic flow path to said capacitor bank of said electronic control unit;
connecting (150) a fourth electronic flow path between the second electronic flow path and the capacitor bank of said electronic control unit;
supplying (160) electric power from the second electronic flow path to said capacitor bank of said electronic control unit; characterized in that
disengaging (170) said second electronic switch by the electronic control unit;
measuring (180) a voltage drop between said capacitor bank of said engine control unit and the ground terminal of said engine control unit by said engine control unit; and
inferring (190) that the first electronic flow path is not functional if the voltage drop between said capacitor bank of said engine control unit and the ground terminal of said engine control unit decreases at a rate that is above a user defined threshold rate.

2. The algorithm (100) for detection of disconnection of redundant power supply to the engine control unit in accordance with Claim 1, further comprising:
disengaging (200) said first electronic switch by the electronic control unit;
measuring (210) a voltage drop between said capacitor bank of said engine control unit and the ground terminal of said engine control unit by said engine control unit; and
inferring (220) that the second electronic flow path is not functional if the voltage drop between said capacitor bank of said engine control unit and the ground terminal of said engine control unit decreases at a rate that is above a user defined threshold rate.