Electronic control unit for a heat-generating electrical device of a vehicle

Abstract

An electronic control unit for a heat-generating electrical device of a vehicle, that includes a microcontroller configured to control the operation of the heat-generating electrical device in dependence on a temperature signal of at least one temperature sensor thermally coupled with the heat-generating electrical device; and at least one electronic thermal protection circuit configured to at least temporarily interrupt the control of the operation of the heat-generating electrical device in dependence on the temperature signal of the at least one temperature sensor thermally coupled with the heat-generating electrical device.

Claims

1. An electronic control unit for a heat-generating electrical device of a vehicle, comprising: a temperature sensor thermally coupled to the heat-generating electrical device; a microcontroller configured to control an operation of the heat-generating electrical device depending on a temperature signal from the temperature sensor; and an electronic thermal protection circuit configured to at least temporarily interrupt the control of the operation of the heat-generating electrical device depending on the temperature signal from the temperature sensor.

2. The electronic control unit according to claim 1, wherein the electronic thermal protection circuit is free of its own microcontroller and/or is configured to be operated without operating software.

3. The electronic control unit according to claim 1, wherein the temperature sensor is configured to provide the temperature signal relating to a temperature in a temperature detection range, wherein the thermal protection circuit is configured to monitor the temperature signal and then interrupt the operation of the heat-generating electrical device if the temperature signal is at or above a predetermined threshold.

4. The electronic control unit according to claim 3, wherein the electronic control unit comprises a second temperature sensor that is thermally coupled with the heat-generating electrical device, and wherein the microcontroller is configured to control the operation of the heat-generating electrical device in dependence of the temperature signal from the temperature sensor, and the electronic thermal protection circuit is configured to at least temporarily interrupt the control of the operation of the heat-generating electrical device in dependence on a temperature signal of the second temperature sensor.

5. The electronic control unit according to claim 1, wherein the electronic thermal protection circuit is configured to monitor the temperature signal with respect to a limit value and to interrupt the operation of the heat-generating electrical device at least temporarily upon detection and determination that the temperature signal meets or exceeds a predetermined limit value.

6. The electronic control unit according to claim 5, wherein the microcontroller is configured to periodically simulate, at the electronic thermal protection circuit, the temperature signal meeting or exceeding the predetermined limit value without the temperature signal actually meeting or exceeding the predetermined limit value, to check a function of the electronic thermal protection circuit.

7. The electronic control unit according to claim 1, wherein the microcontroller is configured to monitor an operating status of the heat-generating electrical device independently of the control of the operation of the heat-generating electrical device.

8. The electronic control unit according to claim 1, wherein the electronic thermal protection circuit is configured to be supplied with electrical power via the same power supply path that supplies power to the heat-generating electrical device.

9. The electronic control unit according to claim 1, wherein the electronic thermal protection circuit comprises a first electronic thermal protection circuit and a second electronic thermal protection circuit, wherein the first electronic thermal protection circuit is configured to at least temporarily interrupt the control of the operation of the heat-generating electrical device in dependence on the temperature signal of a first temperature sensor that is thermally coupled with the heat-generating electrical device; and wherein the second electronic thermal protection circuit is configured to at least temporarily interrupt the control of the operation of the heat-generating electrical device in dependence on a temperature signal of a second temperature sensor that is thermally coupled with the heat-generating electrical device.

10. The electronic control unit according to claim 1, wherein the microcontroller and the electronic thermal protection circuit are arranged in a common housing of the electronic control unit and/or on a common printed circuit board of the electronic control unit.

11. An in-vehicle control system comprising an in-vehicle heat-generating electrical device; and the electronic control unit according to claim 1.

12. The in-vehicle control system according to claim 11, wherein the in-vehicle heat-generating electrical device is a heating device, a vehicle seat heating device, a battery heating device, or an engine heating device.

13. A method of controlling the heat-generating electrical device of the vehicle the electronic control unit according to claim 1, wherein the method comprises: controlling the operation of the heat-generating electrical device by the microcontroller of the electronic control unit in dependence of the temperature signal of the temperature sensor thermally coupled with the heat-generating electrical device; wherein the control of the operation of the heat-generating electrical device is at least temporarily interrupted in dependence on the temperature signal of the temperature sensor thermally coupled with the heat-generating electrical device.

14. The method according to claim 13, wherein the method comprises simulating, with the microcontroller, the temperature signal meeting or exceeding the predetermined limit value without the temperature signal actually meeting or exceeding the predetermined limit value, to check a function of the electronic thermal protection circuit.

15. The method according to claim 14, wherein the simulating step takes place without interrupting a power supply to the heat-generating electrical device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In the following, preferred embodiments of these teachings are explained and described in more detail with reference to the accompanying drawings. The Figures show:

[0031] FIG. 1 shows a schematic representation of an embodiment of the control system according to these teachings;

[0032] FIG. 2 shows a schematic representation of a further embodiment of the control system according to these teachings;

[0033] FIG. 3 shows a schematic representation of a further embodiment of the control system according to these teachings;

[0034] FIG. 4 shows a schematic representation of a further embodiment of the control system according to these teachings; and

[0035] FIG. 5 shows a schematic representation of a further embodiment of the control system according to these teachings.

DETAILED DESCRIPTION

[0036] FIG. 1 shows an in-vehicle control system 100. The in-vehicle control system 100 comprises an in-vehicle heat-generating electrical device 102 and an electronic control unit 10. The in-vehicle heat-generating electrical device 102 may be designed as a heating device and the in-vehicle heat-generating electrical device 102 can be controlled by or with the electronic control unit 10.

[0037] The in-vehicle heat-generating electrical device 102 may be a vehicle seat heating device. However, the control unit 10 can also be used to control a battery heating device or an engine heating device.

[0038] The control unit 10 may include a drive unit 14, which is connected to a power source, for example a battery, via an electrical conductor 12a. The drive unit 14 provides a specific voltage and/or a specific current to the heat-generating electrical device 102 so that the intended operation of the heat-generating electrical device 102 is implemented. The drive unit 14 can comprise, for example, a gate driver and/or a power transistor and is connected to the heat-generating electrical device 102 via the electrical conductor 12b.

[0039] The heat-generating electrical device 102 is connected to the electrical conductor 16a on the ground-side via the electrical conductor 16b and the drive unit 18.

[0040] The electronic control unit 10 comprises a microcontroller 20. The microcontroller 20 is configured to control operation of the heat-generating electrical device 102. The microcontroller 20 is connected to the drive unit 14 via the signal-conducting connections 22a, 22b and to the drive unit 18 via the signal-conducting connections 24a, 24b. The microcontroller 20 can monitor the power state of the drive unit 14 via the signal-conducting connection 22a. The microcontroller 20 can provide control signals to the drive unit 14 via the signal-conducting connection 22b, so that the voltage and/or current provided to the heat-generating electrical device 102 can be set accordingly via the drive unit 14. The microcontroller 20 uses the signal-conducting connection 24a to query the operating status of the drive unit 18. The microcontroller 20 can drive the drive unit 18 via the signal-conducting connection 24b.

[0041] Control instructions can be communicated to the microcontroller 20 from a vehicle occupant or an operator side via a signal-conducting connection 28 and an interface circuit 26.

[0042] The electronic control unit 10 further comprises at least one or two or more than two temperature sensors 30a, 30b designed as NTC thermistors, which are thermally coupled to or with the heat-generating electrical device 102. The temperature sensors 30a, 30b provide a temperature signal or temperature reading relating to the temperature in a temperature detection range. The temperature signals are voltage signals which are provided to the microcontroller 20 via the signal-conducting connections 32a, 32b. The control unit 10 further comprises a 5 volt supply line 50, which is connected to the temperature sensors 30a, 30b and the microcontroller 20. The microcontroller 20 can interpret the voltage signals coming from the temperature sensors 30a, 30b, by taking into account the voltage on the supply line 50, to carry out a temperature determination. The microcontroller 20 controls the operation of the heat-generating electrical device 102 in dependence on the temperature signals from the temperature sensors 30a, 30b that are thermally coupled with the heat-generating electrical device 102.

[0043] The electronic control unit 10 further comprises an electronic thermal protection circuit 34 configured to at least temporarily interrupt the control and./or the operation of the heat-generating electrical device 102 by the microcontroller 20 depending on or in dependence on the temperature signal from the temperature sensor 30a. The temperature signal from the temperature sensor 30a that is processed by the thermal protection circuit 34 is a voltage signal. The voltage signal is transmitted via the signal-conducting connection 38 between the temperature sensor 30a and the thermal protection circuit 34. The electronic thermal protection circuit 34 does not have its own microcontroller. The electronic thermal protection circuit 34 is configured to operate without operating software. Via the signal-conducting connection 46 extending between the thermal protection circuit 34 and the drive unit 14, the thermal protection circuit 34 can deactivate the drive unit 14 or can drive the drive unit 14 in such a way that the operation of the heat-generating electrical device 102 is changed or interrupted.

[0044] The thermal protection circuit 34 is configured to monitor the temperature signal from the temperature sensor. The thermal protection circuit 34 is configured to monitor the temperature signal with respect to a limit value. The thermal protection circuit 34 is configured to monitor the temperature signal and compare the temperature signal to a limit value. If the thermal protection circuit 34 detects or determines a temperature signal from the temperature sensor meets or exceeds a limit value, then the thermal protection circuit 34 can interrupt or temporarily interrupt or stop the operation of the heat-generating electrical device 102. The thermal protection circuit 34 can cancel the interruption of the operation of the heat-generating electrical device or initiate or resume operation of the heat-generating electric device 102 if/when there is a subsequent detection or determination of a temperature value at or below a predetermined value or if there is a limit value underrun or the temperature signal is at or below a predetermined threshold, so that the microcontroller 20 resume or again performs the control of the heat-generating electrical device 102.

[0045] The microcontroller 20 is connected to the thermal protection circuit 34 via the signal-conducting connection 44. Via this connection 44, the microcontroller 20 can monitor the operating status of the drive unit 18 independently of the control of the operation of the heat-generating electrical device 102. Via this connection 44, the microcontroller 20 can perform a functional check of the electronic protection circuit 34. To check the operation of the electronic thermal protection circuit 34, the microcontroller 20 simulates a limit value exceedance of the temperature signal monitored by the electronic thermal protection circuit 34. During proper operation of the thermal protection circuit 34, the drive unit 14 would have to interrupt the power supply to the heat-generating electrical device 102. The microcontroller 20 can check this via the signal-conducting connection 22a, without interrupting the power supply to the heat-generating electrical device 102. Such a check without there being an actual failure provides an advantageous maintenance check to ensure the system is functioning properly. If the system detects a temperature drift, then the system can call for repair before the system is completely deactivated or failure occurs.

[0046] The control device 10 further comprises a voltage regulator 40 connected to the conductor 12a, wherein a rectifier including a fusible element 42 is arranged between the conductor 12a and the voltage regulator 40. The voltage regulator 40 applies a voltage of 5 volts to the supply line 50. The rectifier including the fusible element 42 is further connected to the thermal protection circuit 34 via the supply line 36.

[0047] The electronic thermal protection circuit 34 is supplied with electrical power via the same power supply path as the heat-generating electrical device 102. The microcontroller 20 is supplied with electrical power via a different power supply path than the electronic thermal protection circuit 34 and the heat-generating electrical device 102.

[0048] FIG. 2 shows a control system 100 comprising a temperature sensor 30. The temperature sensor 30 provides a temperature signal to the microcontroller 20 via the signal-conducting connection 32. The temperature signal is further provided to the thermal protection circuit 34, namely via the signal-conducting connection 38. Provided that the temperature detected by the temperature sensor 30 does not exceed a predetermined temperature limit value, then the heat-generating electrical device 102 is controlled via the microcontroller 20. As soon as the temperature limit value is exceeded, however, the thermal protection circuit interrupts, or ensures an interruption of, the operation of the heat-generating electrical device 102.

[0049] The microcontroller 20 can check the operating status of the heat-generating electrical device 102 via the signal-conducting connection 48. In this respect, a functional check of the electronic thermal protection circuit 34 can be performed via the signal-conducting connection 44, in which the microcontroller 20 of the electronic thermal protection circuit 34 simulates a temperature limit value exceedance and then checks the operating status of the heat-generating electrical device 102 via the connection 48.

[0050] FIG. 3 shows a control system 100 in which the microcontroller 20 is connected to the temperature sensor 30b via the signal-conducting connection 32. The thermal protection circuit 34 is connected to the temperature sensor 30a via the signal-conducting connection 38. Thus, the control of the operation of the heat-generating electrical device 102 via the microcontroller 20 is based on the temperature values of the temperature sensor 30b. The interruption of the operation of the heat-generating electrical device 102 by means of the thermal protection circuit 34 is based on the signal of the temperature sensor 30a. In this respect, the microcontroller 20 and the thermal protection circuit 34 use different temperature signals.

[0051] In the embodiment of the control system 100 shown in FIG. 4, the microcontroller 20 takes into account the temperature signal of both temperature sensors 30a, 30b. For this purpose, the microcontroller 20 is connected to the temperature sensor 30a via the signal-conducting connection 32a and to the temperature sensor 30b via the signal-conducting connection 32b.

[0052] The thermal protection circuit 34 only takes into account the temperature signal of the temperature sensor 30a.

[0053] FIG. 5 shows an embodiment of the control system 100 in which the control unit 10 has two thermal protection circuits 34a, 34b. The signal-conducting connections 44a, 44b between the microcontroller 20 and the thermal protection circuits 34a, 34b and the signal-conducting connections 48a, 48b between the microcontroller 20 and the heat-generating electrical device 102 now serve for the functional check of the electronic thermal protection circuits 34a, 34b.

[0054] The thermal protection circuit 34a is connected to the temperature sensor 30a via the signal-conducting connection 38a and takes into account only the temperature signal of the temperature sensor 30b. The thermal protection circuit 34b is connected to the temperature sensor 30b via the signal-conducting connection 38b and takes into account only the temperature signal of the temperature sensor 30b. The microcontroller 20 is connected to both temperature sensors 30b, 30b via the signal-conducting connection 32a, 32b so that the microcontroller 20 can take into account the temperature signals of both temperature sensors 30a, 30b in the control of the operation of the heat-generating electrical device.

TABLE-US-00001 Reference numbers 10 Control unit 12a, 12b Conductor 14 Drive unit 16a, 12b Conductor 18 Drive unit 20 Microcontroller 22a, 22b Signal-conducting connections 24a, 24b Signal-conducting connections 26 Interface circuit 28 Signal-conducting connection 30, 30a, 30b Temperature sensors 32, 32a, 32b Signal-conducting connections 34, 34a, 34b Thermal protection circuits 36 Supply line 38, 38a, 38b Signal-conducting connections 40 Voltage regulator 42 Rectifier & fusible element 44, 44a, 44b Signal-conducting connections 46 Signal-conducting connection 48, 48a, 48b Signal-conducting connections 50 Supply line 100 Control system 102 Heat-generating electrical device