Control device architecture in a motor vehicle

Abstract

The invention relates to a control device architecture in which the required current information or power information is recorded by a control device (4) to be supplied and / or the functional state of the control device (4) is transmitted to an evaluating control device (1; 10) via a suitable communication interface (5, 6). The evaluating control device (1; 10) checks the plausibility of the output current in a comparator (9) against the current information or power information from the device (4) to be supplied. This information can be composed of a typical value depending on the functional state (for example a logic circuit board) and a, for example, measured current of a motor control.

Description

[0001] Description

[0002] Control unit architecture in a motor vehicle

[0003] Due to the trend from combustion engine vehicles to battery-powered vehicles, as well as technological advancements towards autonomous or semi-autonomous driving, the number of electrically operated systems in vehicles is increasing. To counteract the resulting increase in functional complexity and the associated complexity of the vehicle's wiring, future vehicle architectures are increasingly based on so-called server-zone architectures. Functionality is managed by the main computers (servers), while the zone and actuator control units are responsible for power distribution and the control of the actuators and sensors.

[0004] Figure 1 illustrates such an architecture in an example. The zone control units (ZONE-ECUs) are connected to a vehicle battery for power supply. The zone control units can, in turn, directly control, for example, sensors or actuator control units (ACTUATOR ECUs), which then control and, if necessary, supply power to consumers. Consumers can be, for example, lights or electric motors. The control units can be connected to each other and to a main computer (MAIN Computation Unit Application Server) via a CAN bus or other connection standards.

[0005] To maximize the efficiency of the vehicle's electrical system, an energy management system is implemented. A key task of this system is to ensure that sufficient energy is always available for functions essential for the safe operation of the vehicle. In the event of an impending overload of the electrical system, so-called comfort consumers are disconnected from the system.

[0006] An important input parameter for the energy management system is information about the current drawn from the vehicle's electrical system. For this purpose, the current is measured in all relevant supply and load paths and then summed to determine the total current.

[0007] Since this energy management functionality is a safety-relevant function, high reliability requirements apply to the power measurement.

[0008] In load paths where actuators are controlled, the behavioral models of the actuators can be used to verify whether the measured current corresponds to what is expected under the known operating parameters.

[0009] The situation is different with power supply outputs. These outputs supply control units with their own internal intelligence / functions. The device providing the power supply typically has no information about when and how the functions are implemented by the supplied control unit. This means that while the power distribution module can measure the current, it cannot validate it in the same way as when controlling actuators. Due to this lack of validation, implementing a current measurement that meets the requirements of functional safety is very complex.

[0010] To meet standard diagnostic requirements, the supplied control units typically have measuring devices to measure the currents of the controlled loads. In most cases, this allows these supplied control units to determine their respective total current consumption without requiring any additional hardware. Furthermore, these devices have a communication interface through which this total current consumption can be transmitted to a receiver. The portion of the current consumption that cannot be directly measured by the supplied components is then estimated by the components depending on their respective operating state. An electronic device, which, for example, implements the function of an intelligent power distributor (smart power distribution) via electronic fuses (eFuses), supplies one or more electronic devices.These devices can be switched on and off via this power distributor.

[0011] Furthermore, the current output per output can be recorded in the power distributor; thus, it is possible to calculate the current power value if the supply voltage is known.

[0012] For reasons of functional safety in the direction of semi-autonomous or autonomous driving, the reliable and correct reading back of the current or power value is of particular importance, as fault cases must be detected and appropriate measures must be initiated quickly in the event of a fault.

[0013] However, with these devices, the current or power range to be considered is very large due to the different operating states of the device (such as standby mode, active mode, and active mode with differently activated actuators), or the current consumption is unknown. Therefore, verifying the current or power readings from the intelligent power distributor is very difficult or even impossible.

[0014] In contrast, with a constant load (such as a lamp), the current or power range is defined and can be limited (e.g., nominal value + / - tolerance). Therefore, the readout value can be easily checked and validated with the load activated and deactivated.

[0015] The object of the invention is to increase the reliability of current measurement without increasing the complexity of the hardware, in order to be able to perform a plausibility check of the measurement based on the hardware already present in the supplied control units. This object is achieved by a control unit architecture in a motor vehicle with at least one first control unit that supplies current and at least one second control unit that receives the current, wherein the first control unit has a power distributor which is configured to detect the supplied current and which is connected to the second control unit via a supply line, wherein the second control unit has a communication interface which is connected via a communication line to a communication interface of an evaluating control unit.wherein the second control unit has a detection unit for detecting the current received and delivered to a consumer, which is connected to the communication interface, and wherein the second control unit is configured to detect current information from the second control unit and / or to transmit the operating state of the second control unit to the evaluating control unit via the communication interface, and wherein the evaluating control unit has a comparator which is connected to the power distributor of the first control unit and its communication device and is configured to validate the current delivered by the power distributor using the current information from the second control unit.

[0016] Determining the received or delivered current using the sensing unit can, for example, correspond to a measurement. However, it can also be a value that is transmitted, e.g., by the first control unit. It is also possible that determining the value corresponds to querying a value from a memory.

[0017] The supplied current is a load that is used by a consumer. The consumer could be, for example, a motor, a sensor, another control unit, or the like.

[0018] Plausibility checks take place in the comparator and can, for example, involve comparing the current information or a value contained therein with a reference value. Current information is understood to mean any information from which a conclusion about the current can be drawn, such as information about power or energy. The current information can include elements from the following groups: the supplied current (input current), the output current, or a state mode of the second control unit. A state mode can, for example, indicate whether the second control unit is in an energy-saving mode or an active mode. It is possible that there are multiple output currents, for example, because several consumers are supplied with power by the second control unit.

[0019] The evaluating control unit can be the first control unit or a third control unit.

[0020] The evaluating control unit can have either one communication interface for connection with the first control unit and the second control unit, or one communication interface for connection with the first control unit and one communication interface for connection with the second control unit.

[0021] The invention is described in more detail below with reference to exemplary embodiments and the aid of figures. These figures show...

[0022] Fig. 1 Control unit architecture for a motor vehicle,

[0023] Fig. 2 shows a first variant of a control unit architecture according to the invention,

[0024] Fig. 3 shows a second variant of a control unit architecture according to the invention,

[0025] Fig. 4 shows a third variant of a control unit architecture according to the invention.

[0026] Figure 2 shows a first control unit 1, which can be a zone control unit, having a power output 2 and a communication interface 5'. A second control unit 4 is also shown, which can be an actuator control unit and supplies current to a load 12. The load 12 can, for example, control a lamp or a motor 13, or even several actuators, and in particular supply them with the supplied current 14. This is done via the power distributor or power output 2 through a supply line 3.

[0027] The second control unit 4 has a detection unit 11 which determines the received current and, above all, the passed-on current, or estimates it if a determination is not possible, and transmits the value or values ​​to the first control unit 1 via a communication interface 5 and a communication line 6.

[0028] In the embodiment shown in Fig. 2, the first control unit 1 has a comparator 9 which is connected to the power distributor 2 and the communication interface 5' and compares the current value supplied to the second control unit 4 with the current value transmitted by the second control unit 4 and can thus verify the plausibility of the transmitted power.

[0029] In the implementation example of Fig. 2, the first control unit 1 is therefore not only the supplying but also the evaluating control unit, and the second control unit 4 is the control unit to be supplied and evaluated.

[0030] In contrast, in the embodiment shown in Fig. 3, a third control unit 10 is provided as the evaluating control unit, which in this case includes the comparator 9. Here, the communication interface 5' of the first control unit 1 is connected to a first communication interface 5" of the third control unit 10, and the communication interface 5 of the second control unit 4 is connected to a second communication interface 5'" of the third control unit 10. Thus, the current supplied by the first control unit 1 to the second control unit 4 is compared with the current received and passed on by the second control unit 4 in the third control unit 10 as the evaluating control unit. In a further variant, according to Fig.4 the third control unit 10 only has one communication interface 5” which is connected to both the communication interface 5’ of the first control unit 1 and the communication interface 5 of the second control unit 4 via a common communication line 6.

[0031] According to the invention, the required current or power information is acquired by the second control unit 4 to be supplied and / or the functional state of the second control unit 4 is transmitted to the evaluating control unit 1 (e.g., the device with the power distributor 2 or a separate control unit 10 provided for this purpose) via a suitable communication interface 5 (e.g., as a CAN message). The evaluating control unit 1 or 10 verifies the output current in the power distributor 2 with the current or power information from the control unit 4 to be supplied. This information can consist of a typical value depending on the functional state (e.g., of a logic board) and, for example, a measured current from a motor control. This ensures that this power output functions correctly when the measured values ​​are the same or expected measured values ​​are present.

[0032] One advantage of this improvement is that no additional hardware is required. The current values ​​for each operating state are known, and when controlling motors, the motor current is also known or can be measured.

[0033] In the future, the function can be implemented in software in a control unit and can be used in a zone controller and high-performance computer in the sub-function Smart Power Distribution.

Claims

Patent claims 1. Control unit architecture in a motor vehicle comprising at least one first current-supplying control unit (1 ) and at least one second current-receiving control unit (4), wherein the first control unit (1 ) has a power distributor (2) configured to detect the supplied current and connected to the second control unit (4) via a supply line (3), wherein the second control unit (4) has a communication interface (5) which is connected via a communication line (6) to a communication interface (5') of an evaluating control unit (1 ;10) is connected, wherein the second control unit (4) has a detection unit (11) for detecting the received and delivered current (14) to a consumer (12), which is connected to the communication interface (5), and wherein the second control unit (4) is configured to detect current information from the second control unit (4) and / or to transmit an operating state of the second control unit (4) to the evaluating control unit (1, 10) via the communication interface (5), and wherein the evaluating control unit (1, 10) has a comparator (9) which is connected to the power distributor (2) of the first control unit (1) and its communication device (5'; 5") and is configured to validate the current output by the power distributor (2) using the current information from the second control unit (4).

2. Control unit architecture according to claim 1, wherein the evaluating control unit is the first control unit (1).

3. Control unit architecture according to claim 1, wherein the evaluating control unit is a third control unit (10).

4. Control unit architecture according to claim 3, wherein the evaluating control unit has a communication interface (5") for connection with the first (1) and the second control unit (4).

5. Control unit architecture according to claim 3, wherein the evaluating control unit has a first communication interface (5") for connection with the first control unit (1) and a second communication interface (5'') for connection with the second control unit (4).

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