Sensor interfaces

Abstract

Motor vehicle control (202, 302, 402, 702, 1002, 1210, 1218, 1302), comprising: a controller (204, 310, 406, 710) configured to selectively generate a plurality of control signals (sCTRL) corresponding to a plurality of different communication protocols, wherein the control signals (sCTRL) in question have properties corresponding to one of the plurality of different communication protocols; a modulation unit (208, 306) configured to receive one of the control signals (sCTRL) and to generate a modulated communication signal and transmit it via a communication bus (210) which has properties corresponding to a communication protocol of one of the control signals (sCTRL), wherein the communication signal for each of the plurality of different communication protocols is provided to the same communication bus (210); wherein the communication bus (210) is configured to provide the communication signal to a sensor network (212) comprising one or more sensors (212a...212n, 314, 316, 318).

Description

BACKGROUND OF THE INVENTION

[0001] Modern vehicles are equipped with a wide range of sensors, such as airbag sensors, tire pressure sensors, engine sensors, seatbelt sensors, and many others. These sensors provide data on vehicle operation (e.g., wheel speed, deceleration, etc.) to an automotive control unit (ACU). Based on the data received from the sensors, the ACU can determine whether an action should be taken (e.g., when the vehicle's airbags should be deployed).

[0002] Fig. Figure 1 shows a vehicle sensor system 100, including a sensor interface module 102. The sensor interface module 102 has a control interface 104, which is coupled to a controller 106 and a sensor interface 108, which in turn is connected to one or more sensors 110 (e.g. 110a,..., 110n).

[0003] To transmit information to the sensors 110, the sensor interface module 102 includes a modulation unit 112 that modulates a supply voltage (e.g., a change in the input DC voltage) to transmit information to at least one of the sensors 112. When no data is being transmitted, the modulation unit 112 often applies an unmodulated supply voltage (e.g., DC voltage) to the sensors 110. To receive information from the sensors 110, the sensor interface module 102 includes a demodulation unit 114 that demodulates a modulated sensor current signal to receive information from at least one of the sensors 110.

[0004] Various protocols can be used, some of which are incompatible with each other. Therefore, one objective of the invention is to increase flexibility in handling different protocols when communicating with sensors and the like.

[0005] US 2005 / 0146458A1 and DE 102007046572A1 each disclose devices in which communication signals according to different communication standards are provided at different interfaces for communication with different sensors.

[0006] DE 101 12 844 A1 discloses the use of test signals during communication breaks to find errors in a network.

[0007] DE 10 2012 214 636 A1 discloses sensor interfaces. SUMMARY

[0008] A motor vehicle control system according to claim 1, a sensor system according to claim 12, and a method according to claim 24 or 27 are provided. The dependent claims define further embodiments. DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a block diagram of a vehicle sensor system. Fig. Figure 2 is a block diagram of a vehicle sensor system that includes an ACU configured to communicate with sensors using a plurality of different communication protocols. Fig. Figure 3 is a block diagram of a vehicle sensor system that includes a plurality of sensors using PSI5 and / or DSI3 communication protocols. Fig. Figure 4 illustrates in more detail an embodiment of an ACU that is configured to communicate with sensors using a plurality of different communication protocols. Fig. 5A and Fig. Figure 5B illustrates clock diagrams showing the different embodiments of the operation of a disclosed ACU for different communication protocols. Fig. Figure 6 illustrates a procedure for operating an ACU to provide communication signals that have different communication protocols. Fig. Figure 7 illustrates a block diagram of a vehicle sensor system that has an ACU which includes an evaluation unit configured to characterize a sensor network of a motor vehicle system. Fig. Figure 8 is a flowchart showing some embodiments of a method for automatically detecting a communication protocol used by sensors connected to the ACU. Fig. Figure 9 is a flowchart showing some embodiments of a method for characterizing the load characteristics of a sensor network. Fig. Figure 10 is a block diagram of some additional embodiments of a motor vehicle control system configured to characterize an impedance load of a sensor network. Fig. Figures 11A to 11C illustrate clock diagrams showing some embodiments of the operation of a disclosed motor vehicle control system configured to characterize an impedance load of a sensor network. Fig. Sections 12A to 12C illustrate block diagrams showing some embodiments of equivalent circuits that can be used to characterize an impedance load. Fig. Figure 13 is a block diagram of some additional embodiments of a disclosed motor vehicle control system configured to characterize an impedance load of a sensor network. Fig. Figure 14 is a block diagram of an alternative embodiment of a disclosed motor vehicle control system configured to characterize an impedance load of a sensor network. DETAILED DESCRIPTION

[0009] The claimed invention is described below with reference to the drawings, whereby the same reference numerals are generally used to refer to the same elements. For explanatory purposes, numerous specific details are set forth in the following description to provide a thorough understanding of the invention. However, it can be seen that the claimed invention can be realized without these specific details.

[0010] Automotive control units (e.g., engine control units, airbag control units, etc.) can be integrated into a wide range of automotive systems. Each automotive system can encompass a different environment in which an automotive control unit (ACU) must operate. For example, an automotive system may operate according to a variety of different sensor interfaces / communication protocols (e.g., a PSI5 or DSI3 communication protocol) or may involve a load impedance defined by a feature of the automotive system. The diverse environments of automotive systems present challenges for ACUs designed for integration into a wide range of automotive systems.

[0011] For example, conventional ACUs are configured to communicate with sensors using a single communication protocol. This can be due to differences between the various communication protocols. For instance, a DSI2 protocol is incompatible with a PSI5 protocol because the performance characteristics of the two protocols cannot be addressed using the same hardware components. If an ACU is not operating with a communication protocol that matches the sensor interface / protocol, the ACU will be unable to communicate with sensors in the vehicle system.

[0012] Similarly, automotive systems can operate with varying impedance loads. For example, bus wires connecting an ACU and one or more sensors can have different lengths (e.g., between approximately 0 and 12 meters) and carry a load from multiple sensors distributed along the length of the bus wires. The varying wire lengths and sensor configurations result in an LC network with serial and parallel resonant frequencies and distributions that can vary by orders of magnitude (e.g., between 100 kHz and 50 MHz).

[0013] To achieve acceptable results, the coefficients of a control algorithm used by a voltage regulator within an ACU are chosen according to the load configuration. Unfortunately, the load configuration of an automotive system depends on the vehicle's system configuration and is unknown when the ACU is manufactured. Therefore, conventional ACUs use a voltage regulator with standardized coefficients that work for most load configurations. However, such standardized coefficients cause a performance drop in the voltage regulator.

[0014] Accordingly, the present invention relates to a vehicle control unit configured to operate according to a plurality of different communication protocols. By operating the modulation unit to function according to different communication protocols, the ACU can be operated to communicate with multiple sensors that use different communication protocols (e.g., PSI5 and DSI3 communication protocols). In some embodiments, the ACU can additionally or alternatively be configured to generate a test signal that is used to characterize the sensors connected to the ACU (e.g., to characterize a load impedance or a sensor communication protocol) and to selectively modify the operation of the vehicle system to improve the performance of the sensor network.

[0015] Fig. Figure 2 illustrates a block diagram of a vehicle sensor system 200, which includes an ACU 202 configured to communicate with a sensor network 212, which has one or more sensors 212a to 212n that can be operated using various communication protocols.

[0016] The ACU 202 is configured to use the same physical sensor interface module 206 to generate and receive different communication protocols (e.g., PSI5, DSI3, etc.). Using the same physical sensor interface module 206, the ACU 202 can provide the various communication protocols for a sensor network 212 by changing the configuration of the sensor interface module 206.

[0017] In some embodiments, the ACU 202 includes a controller 204 that communicates with the sensor interface module 206, which has a modulation unit 208. To receive information from a sensor network 212, the controller 202 further includes a demodulation unit 214 that demodulates a modulated signal to receive information from at least one of the sensors 110. The controller 204 is configured to receive control signals S CTRL generated signals that have a value related to a communication protocol (e.g., PSI5, DSI3, etc.). For example, the controller 204 can optionally generate a control signal S CTRL generate a first value that corresponds to a first communication protocol, or a control signal S CTRL , which has a second value that corresponds to a second communication protocol.

[0018] The modulation unit 208 is configured to receive the control signal SCTRL receives and generates a communication signal based on it, which has characteristics (properties) that are defined by the control signal S CTRL The communication signal, configured to transmit information to the one or more sensors 212a to 212n, is provided to the one or more sensors 212a to 212n via a communication bus 210.

[0019] The communication protocols generated by the ACU 202 share physical similarities. In some embodiments, the various communication protocols are transmitted using the communication bus 210, which has the same number of bus wires. For example, the communication bus 210 may comprise a two-wire sensor bus, having a first wire 210a and a second wire 210b. In other embodiments, the various communication protocols may transmit data transmission signals using voltage modulation and receive sensor data using current modulation (e.g., a change in the supply current drawn by the sensor), or vice versa. For example, the modulation unit 208 may be configured to generate a communication signal that includes a modulated supply voltage (e.g., a change in the input DC voltage) or a modulated current.

[0020] The ACU 202 can determine a communication protocol type that is used by one or more sensors 212a to 212n in various ways. In some embodiments, a communication protocol can be set by a microcontroller, which causes the ACU 202 to operate according to the communication protocol. For example, after the ACU 202 has been integrated into a motor vehicle system, a microcontroller can send a command to the controller 204 that defines a communication protocol for the motor vehicle system. In other embodiments, the ACU 202 can initially generate communication signals using a first communication protocol, and when the ACU 202 receives an error signal from one or more sensors 212a to 212n, it switches to generating communication signals using a different, second communication protocol.

[0021] Since the ACU 202 is capable of generating communication signals with different communication protocols, it can communicate with one or more sensors 212a to 212n using these different protocols. This allows the ACU 202 to be integrated into a variety of different automotive sensor systems without having to predefine the communication protocol of a particular system. For example, in some embodiments, the ACU 202 can be integrated into an airbag sensor system operating according to a PSI5 communication protocol. In alternative embodiments, the ACU 202 can be integrated into the sensor system of a power steering system operating according to a DSI3 protocol. In another alternative embodiment, the ACU 202 can have different transceivers, each transceiver being controlled by a separate control signal (S). ctrl1 ...S ctrlN) is controlled. Using separate control signals, the ACU 202 assigns one protocol (e.g., PSI5) to some of the transmitters and another protocol (e.g., DSI3) to the remaining transmitters and receivers.

[0022] Fig. Figure 3 illustrates a vehicle sensor system 300 comprising a plurality of sensors 314 to 318 which use the standardized Peripheral Sensor Interface 5 protocol (PSI5 protocol) and / or the standardized Distributed System Interface3 protocol (DSI3 protocol) for an airbag sensor system which has an airbag controller configured to control the operation of the airbags in a motor vehicle.

[0023] In the vehicle sensor system 300, an airbag control unit 302 includes a control unit 304, which is configured to control the operation of a sensor interface module 304 comprising a voltage modulation unit 306 and a current demodulation unit 308. The voltage modulation unit 306 is configured to generate a communication signal that includes a modulated voltage. The current demodulation unit 308 is configured to demodulate a modulated current that it has received from a plurality of sensors 314 to 318.

[0024] The ACU 302 is connected to a plurality of sensors 314 to 318 via a communication bus 210 (e.g., a two-wire communication bus). In some embodiments, the plurality of sensors 314 to 318 can use a single communication protocol. For example, in some embodiments, the plurality of sensors 314 to 318 can use a PSI5 communication protocol or a DSI3 communication protocol. In other embodiments, the plurality of sensors 314 to 318 can use different communication protocols. For example, the communication bus 210 can connect the airbag control unit 302 to a first sensor 314 and a second sensor 316, which are configured to use the PSI5 communication protocol, and to a third sensor 318, which is configured to use the DSI3 communication protocol.

[0025] Since the PSI5 and DSI3 communication protocols share a number of characteristics at the physical level, the airbag control unit 302 is capable of generating communication signals for both the PSI5 and DSI3 communication protocols, which use the same hardware. For example, both the PSI5 and DSI3 communication protocols are connected to the majority of sensors 314 to 318 via a two-wire communication bus 210. Furthermore, both the PSI5 and DSI3 communication protocols communicate with the majority of sensors 314 to 318 using voltage modulation (achieved by the modulation unit 306) and receive information from sensors using current demodulation (achieved by the demodulation unit 308).

[0026] In some embodiments, the controller 310 can be configured to execute different software commands stored in memory 312 to generate a control signal S CTRL to generate a signal that complies with the PSI5 and DSI3 communication protocols. For example, the controller 310 can execute an initial software instruction set that generates a control signal S CTRL defined, which has a value that drives the voltage modulation unit 306 to generate a PSI5 communication signal, or the controller 310 can execute a second software instruction set that generates a control signal S CTRL defined, which has a value that drives the voltage modulation unit 306 to generate a DSI3 communication signal. The control signals S CTRLThey can also be used to configure some time windows in which the sensor interface module 304 acts as a receiver to decode a current-modulated sensor signal according to a PSI5 protocol, and other time windows in which the sensor interface module 304 acts as a receiver to decode incoming messages according to the DSI3 protocol.

[0027] Fig. Figure 4 illustrates a vehicle sensor system 400, which includes a more detailed embodiment of a disclosed automotive control unit (ACU) 402 configured to operate according to various communication protocols. The ACU 402 comprises a sensor interface module 404, which has a first reference voltage source 408 configured to provide a control signal S CTRL received from the controller 406 and based on this a variable reference signal V refThe reference voltage source 408 is coupled to a closed-loop control system 410, which generates a digital control signal D. CTRL generated, which is based on the variable reference voltage V ref based on the digital control signal D CTRL is connected to an output driver stage 412, which regulates an output voltage at the output node 414.

[0028] The output driver stage 412 comprises a high-side current source 412a and a low-side current source 412b. To increase the output voltage at the output node 414, the current generated by the high-side current source 412a can be increased. Conversely, to decrease the output voltage at the output node 414, the current generated by the high-side current source 412a can be decreased and / or the current generated by the low-side current source 412b can be increased. In some embodiments, an RLC network 416 can be coupled to the sensor interface module 404 to limit noise and dampen line resonance.

[0029] The controller 402 is configured to selectively drive the sensor interface module 404, communication signals S com to be generated according to a plurality of different communication protocols. The communication signals S comare then provided to a sensor network 212, which includes one or more sensors. In some embodiments, the controller 406 is configured to drive the output driver stage 412, a communication signal S com by changing the reference voltage V ref , which is output by the reference voltage source 408. Changing the reference voltage V ref This results in the output voltage at output node 414 being changed in a manner consistent with a communication protocol. In other embodiments, the controller 402 is configured to drive the output driver stage 412, which sends a communication signal S com by generating a supplementary control signal S CTRL to generate a signal that is fed directly into the closed control loop 410. The supplementary control signal S CTRL ' is configured so that the value of the control signal D CTRLis modified such that the output voltage at output node 414 is changed in a manner consistent with a communication protocol. In some embodiments, the control signal S CTRL 'a digital value of the control signal S CTRL change.

[0030] In some embodiments, the different communication protocols may have different synchronization pulses. For example, in airbag systems, a PSI5 communication protocol may include a synchronization pulse with an initial voltage modulation with a rising edge, while a DSI3 communication protocol may include a synchronization pulse with an initial voltage modulation with a falling edge. Therefore, to communicate using a PSI5 communication protocol, the controller 406 can modify the output voltage at output node 414 so that the communication signal includes synchronization pulses with an initially rising voltage. Alternatively, to communicate using a DSI3 communication protocol, the controller 406 can modify the output voltage at output node 414 so that the communication signal includes synchronization pulses with an initially falling voltage.

[0031] In other embodiments, the different communication protocols can have different data rates. For example, a PSI5 or a DSI3 communication protocol in a power steering system can be defined by a synchronization pulse width and a gap width between synchronization pulses. Therefore, the controller 406 can modify the output voltage at the output node 414 such that the communication signal has synchronization pulses with a communication protocol-specific pulse width or gap width.

[0032] In some embodiments, the controller 406 can include a memory element 418 configured to store different sets of modulation characteristics (e.g., timing of synchronization pulses, width of synchronization pulses, etc.) corresponding to different communication protocols. The controller 402 is configured to receive a control signal S CTRLis generated based on a group of modulation characteristics stored in memory element 418, corresponding to a communication protocol. For example, the controller 402 can generate a first control signal (which, for example, has a first digital value corresponding to a PSI3 communication protocol) based on a first group of modulation characteristics stored in memory element 418, or generate a second control signal (which, for example, has a second digital value corresponding to a DSI5 communication protocol) based on a first group of modulation characteristics stored in memory element 418. Fig. Figures 5A to 5B illustrate clock diagrams showing exemplary operation of a disclosed ACU (e.g., according to ACU 202). The clock diagrams illustrate how a disclosed controller can modify the operation of an ACU to generate communication signals according to different communication protocols.

[0033] Fig. 5A illustrates clock diagrams 500 and 506, which show some examples of the operation of an ACU for a PSI5 communication protocol.

[0034] Clock diagram 500 illustrates a communication signal that uses a PSI5 protocol and is generated by a disclosed ACU. At time t0, the ACU is switched on and begins transmitting a communication signal 502, which includes a modulated voltage, to one or more sensors. At time t1, a first synchronization pulse 504a is generated. The first synchronization pulse 504a includes a modulated voltage increased by a voltage value greater than V. th1 increases. The voltage increase by a voltage value greater than V th1 Indicates that the PSI5 communication protocol is used. The first synchronization pulse 504a also has a length l1, which is defined according to the PSI5 communication protocol.

[0035] At time t2, a first response 510a (e.g., a data packet) containing a modulated current 508 is received from a sensor. The first response 510a indicates that the sensor is using the PSI5 communication protocol, since if the sensor were not using the PSI5 communication protocol, it would not respond to the first synchronization pulse 504a and thus would not receive a response. At time t3, a second synchronization pulse 504b is transmitted. The time gap g1 between the first synchronization pulse 504a and the second synchronization pulse 504b (i.e., g1 = t3 - t1) is defined to have a value according to the PSI5 communication protocol.

[0036] Fig. Figure 5B illustrates clock diagrams 512 and 518, which show some examples of the operation of an ACU for a DSI3 communication protocol.

[0037] Clock diagram 512 illustrates a communication signal that uses a DSI3 protocol and is generated by a disclosed ACU. At time t0, the ACU is switched on, and the ACU begins to transmit a communication signal 514, which includes a modulated voltage, to one or more sensors. At time t2, a first synchronization pulse 516a is generated. The first synchronization pulse 516a includes a modulated voltage increased by a voltage value greater than V. th2 drops. The voltage drop by a voltage value greater than V th2 Indicates that the DSI3 communication protocol is used. The first synchronization pulse 516a has a length l2, which is defined according to the DSI3 communication protocol.

[0038] At time t5, a first response 522a, comprising a modulated current 520, is received from a sensor. The first response 522a indicates that the sensor is using a DSI3 communication protocol, since if the sensor were not using the DSI3 communication protocol, it would not respond to the first synchronization pulse 516a and thus would not receive a response. At time t5, a second synchronization pulse 516b is transmitted. The time gap g2 between the first synchronization pulse 516a and the second synchronization pulse 516b (i.e., g2 = t1 - t3) is defined to have a value according to the DSI3 communication protocol.

[0039] Fig. Figure 6 illustrates an exemplary procedure 600 for operating a controller to provide communication signals that have different communication protocols.

[0040] Although the disclosed methods (e.g., methods 600, 800, and 900) are illustrated and described below by a series of actions or events, it should be understood that the illustrated sequence of these actions or events is not to be interpreted in a limiting sense. For example, some actions may occur in different sequences and / or simultaneously with other actions or events in addition to those illustrated and / or described in this document. Furthermore, it is possible that not all of the illustrated actions are necessary to implement one or more aspects or embodiments of the description contained in this document. It is also possible that one or more of the actions presented in this document are performed in one or more separate actions and / or phases.

[0041] At 602, an automotive control unit (ACU) is provided, which has a controller configured to operate according to a plurality of different communication protocols. For example, the ACU can be configured to operate according to a first communication protocol and / or a second communication protocol.

[0042] In the 604, the controller is operated in such a way that it generates control signals according to a plurality of different communication protocols. The control signals have values ​​that are each associated with one of these multiple communication protocols. For example, the controller can be operated in such a way that it generates a control signal with a first value corresponding to a first communication protocol, and a second control signal with a second value corresponding to a second communication protocol. By generating control signals corresponding to different communication protocols, the ACU is able to connect to sensors that operate using different communication protocols.

[0043] At 606, a communication signal is generated that has a protocol corresponding to a value of the control signal. For a first value of the control signal, a communication signal can be generated that has a first communication protocol, while for a second value of the control signal, a communication signal can be generated that has a second communication protocol.

[0044] Fig. Figure 7 illustrates a block diagram of some embodiments of a vehicle sensor system having an ACU 702 which includes an evaluation unit 704 configured to characterize a sensor network 212 of a motor vehicle system.

[0045] Although Fig. 7 describes the evaluation unit 704 as being integrated with a controller 714 that is configured to operate according to a plurality of different communication protocols, it is clear that the evaluation unit 704 can also be integrated with a controller 714 that is not operated according to a plurality of different communication protocols.

[0046] The evaluation unit 704 communicates with the closed-loop control system 708. The evaluation unit 704 is configured to drive the sensor interface module 706 (e.g., via a controller 716) to generate a test signal s test to generate a signal that is provided to the sensor network 212. The evaluation unit 704 can be configured to characterize the sensor network that provides the test signal s. testused to automatically detect a communication protocol used by one or more sensors of the sensor network 212, and / or to determine an electrical behavior (e.g. load characteristics) of the one or more sensors.

[0047] In some embodiments, the evaluation unit 704 includes a load characterization unit 710 configured to provide a test signal s test is generated, which is configured to characterize the sensor network 212. In such embodiments, the evaluation unit 704 can process the test signal s test , which includes a modulated voltage or modulated current, during time windows in which data is not being received from sensor network 212. Sensor network 212 is configured to send a response s res on the test signal s test induced, which is provided to the evaluation unit 704. The response sres is indicative of the characteristics of the sensor network 212.

[0048] The evaluation unit 704 is configured to evaluate the electrical behavior of the sensor network 212 based on the response s res characterized. In some embodiments, the evaluation unit 704 can provide the response s res Measure and generate one or more parameters from the measured response that describe the sensor network 212. For example, the evaluation unit 704 can generate a capacitance value, an induction value and / or a resistance value of the sensor network 212.

[0049] The evaluation unit 704 can further be configured to adjust the operation of the closed-loop control system 708 based on the characterization. In some embodiments, the evaluation unit 704 can adjust the operation of the closed-loop control system 708 by comparing the characterization with equations or lookup tables to determine one or more control parameters c. par to generate a system that defines an optimized controller. The single control parameter or multiple control parameters c par are then provided to the closed-loop control unit 708 to optimize operation. In other embodiments, the evaluation unit 704 can be operated to improve the operating conditions according to an iterative process. In such an embodiment, the evaluation unit 704 can iteratively adjust one or more control parameters c. par change to search for limits in the control parameters cpar to find where the vibrations begin. Once a stable range has been determined, the final operating settings could be chosen with sufficient margin relative to the limits.

[0050] In other embodiments, the evaluation unit 704 comprises an automatic protocol detector unit 712, which is configured to automatically determine a communication protocol used by the sensor network 212. The automatic protocol detector unit 712 is configured to drive the sensor interface module 706 (e.g., via the controller 716) and a plurality of test signals S. test(e.g., a synchronization pulse or a command / message) or corresponding different protocols (e.g., PSI5, DSI3, etc.). In some embodiments, the automatic protocol detector unit 712 can be programmed to execute a sequence of known communication protocols. In such embodiments, the timing and / or the length of the test signals S can be test can be set through programming.

[0051] If the test signal s testIf the communication protocol used by one or more sensors within the sensor network 212 matches the sensor's communication protocol, the sensor(s) will respond to the test signals. Therefore, if the sensor network 212 responds to the stimulus, the evaluation unit 704 can conclude that one or more sensors within the connected sensor network 212 are using the known protocol. For example, a sensor using a PSI5 communication protocol will respond when it receives a synchronization pulse with an initially rising voltage, but will not respond when it receives a synchronization pulse with an initially falling voltage.Similarly, a sensor using a DSI3 communication protocol will respond when it receives a synchronization pulse with an initially falling voltage, but will not respond when it receives a synchronization pulse with an initially rising voltage.

[0052] In one embodiment, the evaluation unit 704 can drive the sensor interface module 706, a test signal S test to output a synchronization signal that includes one of several known protocols. If the evaluation unit 704 receives a response from the sensor network 212, it can determine that the sensor network 212 is using the first of several known communication protocols. If the evaluation unit 704 does not receive a response from the sensor network 212 within a predefined period, it can output a test signal S. testThe evaluation unit 704 generates synchronization signals that correspond to one of several known communication protocols. If the evaluation unit 704 receives a response from the sensor network 212, it can determine that the sensor network 212 is using the second of several known communication protocols. If the evaluation unit 704 does not receive a response from the sensor network 212 within a predefined period, it can continue to send additional test signals until a communication protocol of the sensor network 212 is identified.

[0053] In some embodiments, the evaluation unit 704 is configured to initially output a test signal S test sends a synchronization pulse with a falling voltage, since it is a test signal S test, which has a synchronization pulse with a rising voltage, could damage DSI3 sensors that are not configured to process PSI5 pulses. The evaluation unit 704 waits for a response from the sensor network 212. If the sensor network includes PSI5 sensors, no response is sent, and the evaluation unit 704 is configured to receive a subsequent test signal S test sends a synchronization pulse with an increasing voltage.

[0054] Fig. Figure 8 illustrates a procedure 800 for operating an ACU configured to automatically detect a communication protocol used by sensors connected to the ACU.

[0055] In 802, an automotive control unit (ACU) is provided that has a controller configured to operate according to a plurality of different communication protocols. In 804, the controller is driven to generate a communication signal according to a first communication protocol. In some embodiments, the communication protocol may include a DSI3 communication protocol.

[0056] In 806, the communication signal is provided to one or more sensors connected to the ACU.

[0057] In the event that sensor networks are uniformly equipped with sensors using the same protocol, the ACU—if a response is received from one or more sensors (at 808)—continues to operate according to the communication protocol at 810, and procedure 800 then terminates. However, if no response is received from one or more sensors (at 808), the communication protocol is switched so that at 812 it generates a modulated communication signal according to a different communication protocol. Procedure 800 then returns to 806, where the other communication signal is provided to one or more sensors.

[0058] Alternatively, method 800 would be used if the sensor networks are uniformly equipped with sensors using the same protocol (e.g., as in Fig. (3 shown) iteratively perform steps 804 to 810 to conduct tests with respect to a series of possible communication protocols defined within a controller. For example, the procedure would iteratively perform steps 804 to 810 to conduct tests with respect to a series of possible communication protocols, including a first communication protocol, a second communication protocol, and so on.

[0059] Fig. Figure 9 is a flowchart showing some embodiments of a method 900 for characterizing a sensor network in order to determine load characteristics of a sensor network connected to a controller.

[0060] At 902, an automotive control unit (ACU) is provided that has a sensor interface module connected to a sensor network comprising one or more sensors. In some embodiments, the ACU may include a controller configured to operate according to a plurality of different communication protocols. In other embodiments, the ACU may include a controller configured to operate according to a single communication protocol.

[0061] In step 904, network characterization is performed to characterize the sensor network. Network characterization involves characterizing the sensor network by determining one or more parameters that describe the impedance load. In various embodiments, the one or more parameters may include a complex impedance of the load, one or more components of an equivalent circuit that describes the impedance load, or one or more components of a transfer function that describes the impedance load. In some embodiments, the network characterization is performed by steps 906 through 912. In some embodiments, the characterization phase may be divided into multiple characterization time slots, which may have multiple iterations and use different signal types.

[0062] At 906, a test signal is generated. In some embodiments, the test signal may include a test signal configured to characterize a load impedance of the sensor network. The test signals may be changes in the supply current (e.g., current modulation) or changes in the supply voltage (e.g., voltage modulation). In the case of a test current, the network response is a change in the supply voltage, and in the case of a change in the supply voltage, the response is a change in the current drawn by the sensor network.

[0063] In version 908, the test signal is sent during an open time window in which no data communication takes place. In some embodiments, a supply voltage is applied across the output signal to generate a test signal as soon as an open time window has been identified.

[0064] At 910, a network characterization response is measured. This response may include a response induced by the sensor network in response to the test signal. In some embodiments, the sensor network may be active during network characterization, so that sensor operating points can influence attenuation effects in the network.

[0065] In 912, one or more characterization parameters are determined based on the measured response of the test signal. In some embodiments, the characterization parameters can be determined by fitting an equivalent circuit to the measured response.

[0066] In version 914, the sensor interface module is updated based on the characterization parameters. In some embodiments, the sensor interface module can be updated to optimize its operation based on specific characterization parameters.

[0067] Fig. Figure 10 illustrates a block diagram of some additional embodiments of a vehicle sensor system 1000 which has a vehicle control unit (ACU) 1002 configured to characterize an impedance load of a sensor network 212.

[0068] The ACU 1002 includes the sensor interface module 1004, which has an evaluation unit 1006 configured to selectively modify the operation of the closed-loop control system 1008 to determine a value of the second control signal s CTRL2 to control in such a way that it drives the output driver stage 412, a test signal s testto generate. Based on a response s res on the test signal s testThe evaluation unit 1006 can characterize the sensor network 212 to determine information about the actual load settings of the sensor network 212. In some embodiments, the evaluation unit 1006 can be configured to change the supply voltage output from the output driver stage 412. Since changing the supply voltage forces a change in the current flowing back from the sensor network 212, a transfer function of the sensor network 212 can be calculated by characterizing a change in the response current corresponding to a change in voltage. In other embodiments, the evaluation unit 1006 can be configured to change the current output from the ACU 1002 and measure a load voltage induced by the sensor network 212. From the voltage and current information, the impedance can be calculated (e.g., by dividing the voltage by the current).

[0069] In some embodiments, the evaluation unit 1006 can selectively modify the operation of the closed-loop control system 1008 by providing the closed-loop control system 1008 with one or more control parameters c. par be provided in such a way that the closed control loop 1008 receives a second control signal s CTRL2 This generates the output driver stage 412, which then sends the test signal s test to generate. In some embodiments, the evaluation unit 1006 can dynamically adjust the control parameters c. par so that the closed-loop control system 1008 is operated at different times using different control parameters. For example, the closed-loop control system 1008 can be operated according to a first set of control parameters to measure the test signal s. testto generate. After characterization, the closed-loop control system 1008 can be operated according to a second set of control parameters configured to provide an output signal with optimized settings based on the acquired bus knowledge.

[0070] In some embodiments, the evaluation unit 1006 is configured to dynamically characterize the sensor network 212. For example, the evaluation unit 1006 can perform an initial characterization (e.g., sending an initial test signal and receiving an initial response) during an initial time window between synchronization signals and adjust the operation of the closed-loop control system 1008 based on this characterization. The evaluation unit 1006 can subsequently perform a second characterization during a second time window after the first and adjust the operation of the closed-loop control system 1008 based on both the initial and subsequent characterizations. By dynamically characterizing the sensor network 212, the evaluation unit 1006 can adapt to changes in the sensor network 212 (e.g., due to temperature changes, sensor damage, etc.).

[0071] In some embodiments, the test signal s test The modulated voltage must have a voltage change value smaller than that of a synchronization pulse, such that the modulated voltage is insufficient to induce a response from the sensor network 212 (i.e., to keep the sensor in a static operating state). For example, the evaluation unit 1006 can drive the closed-loop control unit 1008 to change the supply current of the high-side or low-side current sources 412a or 412b to generate a modulated voltage. The response of the sensor network 212 to the modulated voltage is a change in the current drawn by the sensor network 212. In other embodiments, the test signal s test The sensor network 212 responds to the modulated current with a change in the supply voltage.

[0072] In various embodiments, the evaluation unit 1006 can characterize a load response of the sensor network 212 according to one or more characterization parameters. In some embodiments, the one or more characterization parameters can include a complex impedance of the sensor network 212. In other embodiments, the one or more characterization parameters can include electrical parameters of an equivalent circuit of the sensor network 212. For example, a measured response can be applied to an equivalent circuit, and the one or more characterization parameters (e.g., capacitance, inductance, resistance, etc.) of the equivalent circuit can be extracted to characterize the sensor network 212.In other embodiments, one or more characterization parameters can correspond to a transfer function configured to model the operation of the sensor network 212.

[0073] Based on the characterization, the evaluation unit 1006 can determine one or more controller parameters c. par adjust to adapt the closed-loop control 1008 to characterize the actual connected sensor network (i.e., to change the closed-loop control 1008 from operation with standardized coefficients that work with most load devices to operation with specific coefficients that take into account improved performance of the voltage regulator). Fig. References 11A to 11C illustrate clock diagrams that depict the operation of a disclosed motor vehicle control system for different bus modes (e.g., for synchronous and asynchronous bus modes).

[0074] Fig. Figure 11A illustrates clock diagrams 1100 and 1108, which depict the operation of the disclosed automotive control unit configured to determine an impedance load of a sensor network using a synchronous bus mode. Clock diagram 1100 illustrates a communication signal comprising a modulated voltage generated by a disclosed ACU. Clock diagram 1108 illustrates a response comprising a modulated current induced by a sensor network in response to a modulated voltage.

[0075] It is desirable that in a synchronous bus mode, a voltage can be varied without a response from a sensor network (i.e., while a sensor is held passively), as long as the voltage change does not exceed a minimum amplitude specified for a synchronization pulse. Therefore, the sensor interface module can send a test signal 1104 within a time window between synchronization pulses 1106 without inducing a response from a sensor (i.e., during time windows in which no data communication takes place).

[0076] At time t0, the ACU is switched on and begins transmitting a communication signal 1102, comprising a modulated voltage, to one or more sensors. In some embodiments, before a first synchronization pulse 1106a is sent, an initial characterization can be performed by sending a first test signal 1104a, comprising a modulated voltage, at time t1. The first test signal 1104a induces a first response 1112a, which is indicative of the load on the sensor network.

[0077] At time t2, a first synchronization pulse 1106a is generated. The first synchronization pulse 1106a comprises a modulated voltage that is increased by a voltage value greater than the minimum amplitude specified in a synchronization pulse specification. After the transmission of the first synchronization pulse 1106a, a first data packet 1114a is received from a first sensor at time t3. The first data packet 1114a comprises a current signal that a sensor interface module receives from a sensor. If the ACU is connected to multiple sensors, multiple data packets are received (e.g., one from each sensor). For example, an ACU connected to two sensors would also receive a second data packet 1114b, which is received from a second sensor at time t4.

[0078] Before sending a second synchronization pulse 1106b, the communication bus is quiet. During this quiet period, a second test signal 1104b can be output by the ACU at time t5. This second test signal 1104b induces a second response 1112b, which is indicative of the load on the sensor network. During subsequent time windows (between synchronization pulses), additional test signals can be sent to further characterize the sensor network.

[0079] If a single time window is not large enough to perform a complete bus characterization procedure, the bus characterization procedure can be distributed across multiple time windows. For example, information for reconfiguring the ACU can be obtained from a combination of the first test signal 1104a, a second test signal 1104b sent after the first synchronization pulse 1106a, a third test signal 1104c sent after the second synchronization pulse 1106b, and so on. In some embodiments, sensors can be active during network characterization, as the operating points of the sensors can be assumed to influence the attenuation effects in the sensor network.

[0080] Fig. Figure 11B illustrates clock diagrams 1116 and 1122, which depict the operation of the disclosed automotive control system configured to determine an impedance load response of a sensor network using an asynchronous protocol. Clock diagram 1116 illustrates a communication signal comprising a modulated voltage generated by a disclosed ACU. Clock diagram 1122 illustrates a response comprising a modulated current induced by a sensor network in response to a modulated voltage.

[0081] At time t0, the ACU is switched on, and the ACU begins to transmit a communication signal 1118, which includes a modulated voltage, to one or more sensors. As in Fig. Figure 11B illustrates that a sensor waits a certain time Δt (e.g., defined from time t0) after receiving a supply voltage and then automatically transmits a first data packet 1128a. The first data packet 1128a has a defined data rate (e.g., a data frame length, a gap size, etc.). In some embodiments, initial characterization can be performed before the first data packet 1128a is sent by generating a first test signal 1120a as a modulated voltage at time t1. In response to the first test signal 1120a, a first response 1126a, comprising a modulated current, is induced by the sensors.

[0082] At time t2, the first data packet 1128a is received by the sensors. After the first data packet 1128a has been received, there is an initial time gap t. gap1130a, before a second data packet 1128b is received. In some embodiments, the ACU—since the sensor data rate and clocking are not precise—can estimate the length of the first time gap t. gap 1130a measure without a test signal within the first time interval t gap to place 1130a.

[0083] At time t3, a second data packet 1128b is received from the sensors. After the second data packet 1128b has been received, the ACU sends a second test signal 1120b at time t4. The second test signal 1120b induces a second response 1126b, which has a magnitude that falls within a second time interval t. gap1130b fits, which is equal to the first gap. In some embodiments, the size of the time gaps (e.g., 1130a, 1130b, etc.) can be continuously measured, and the length of a subsequent test signal can be based on the size of the time gaps measured during one or more of the preceding data packet transmission periods.

[0084] Fig. Figure 11C illustrates the clock diagrams 1132 and 1138, which depict the operation of the disclosed automotive control unit configured to determine a load response from a sensor network using an asynchronous protocol for an ABS (automatic braking system). At time t0, the ACU is switched on and begins transmitting a communication signal 1134, comprising a modulated voltage, to one or more sensors. In some embodiments, an initial bus characterization can be performed by generating a first test signal 1136a, comprising a modulated voltage, at time t1. In response to the first test signal 1136a, a first response 1142a, comprising a modulated current, is induced by the sensors.

[0085] A sensor waits a specific time Δt after receiving a supply voltage and then automatically transmits an initial data pulse 1144a. At time t2, the first data packet 1144a is received by the sensors. After the initial data pulse 1144a has been received, there is a time gap t. gap1 1146a, before the next data pulse is received. It is desirable that the ABS sensors send data pulses that indicate the edges of a magnetic pole wheel passing through zero crossings. Therefore, if the speed of a vehicle changes, the gap between data pulses also changes (for example, the faster the vehicle travels, the faster the pole wheel rotates, so the distance between zero crossings decreases). Since the distance between the data pulses is variable, the ACU can determine the length of a first time gap t. gap1 1146a measure without placing a test signal within the first time gap.

[0086] At time t3, a second data pulse 1144b is received by the sensors. After the second data pulse 1144b has been received, the ACU sends a second test signal 1136b, which induces a second response 1142b, the magnitude of which falls within a second time interval t. gap2 1146b fits. Since the size of the second time gap t gap2 Since 1146b depends on the speed of a motor vehicle, the second test signal 1136b can be detected within the second time gap t. gap2 1146b together with an additional margin t th A component is positioned to ensure that the second test signal 1136b and the second response 1142b do not interfere with a third data pulse 1144c, even when the vehicle is traveling at maximum acceleration. In some embodiments, if the vehicle is traveling too fast, the ACU may be forced to postpone characterization until the vehicle slows down again.

[0087] Fig. 12A illustrates a block diagram 1200 illustrating the application of an equivalent circuit comprising a transmission line model 1204 to generate one or more characterization parameters.

[0088] As shown in block diagram 1200, an evaluation unit 1202 is configured to provide a test signal s test generates and measures a response that is determined by the test signal s testThe evaluation unit 1202 then evaluates the measured response by fitting a transmission line model 1204, configured between an ACU 1206 and a sensor network 212, to the measured response. Fitting the transmission line model 1204 to the measured response makes it possible to determine values ​​of the transmission line components and use them as characterization parameters that characterize the sensor network. In some embodiments, the transmission line model 1204 can be stored in a memory element within the evaluation unit 1202.

[0089] In some embodiments, measurements at different frequencies, step responses, etc., are performed to determine components of the equivalent circuit and to obtain sufficient data for characterizing the sensor network. For example, the bus evaluation unit receives the response amplitude and phase shift at each frequency. Therefore, to characterize an equivalent circuit with six unknown components, measurements must be taken at three (3) different frequencies to obtain six (6) measurements.

[0090] Fig. 12B and Fig. Section 12C illustrates some examples of equivalent circuits that can be used to characterize a received response. Fig. Figure 12B illustrates a block diagram 1208 of an equivalent circuit comprising a low-pass model network 1212 with lumped switching elements.

[0091] The equivalent circuit includes an ACU 1210, which applies a voltage to a sensor network 1214. In this case, the ACU 1210 includes a regulated current source that changes the supply current according to information from a controller and that adjusts the supply current in response to feedback from the system output to maintain a stable voltage.

[0092] The 1212 network comprises the line inductance L, a line resistance R, and a line capacitance C. Different values ​​of the components of the low-pass model represent variations in the communication bus length (e.g., between a few centimeters and 12 meters). In some embodiments, blocking capacitors C may also be included. b within the ACU 1210 and the sensor network 1214, as well as a resistor connected in series with the blocking capacitor in the sensor network 1214, are taken into account.

[0093] The 1212 network is precise enough for the ABS sensor because ABS systems use point-to-point sensor connections. The 1212 network can also be used for PSI5 and DSI3 communication protocols. The reason why it is possible to approximate these complex buses with simple models is that buses exhibiting different resonance modes at different frequencies do not achieve high Q-factors for each resonance, as the other network branches, which do not resonate at the same frequency, provide additional damping. Furthermore, resonance frequencies above the one-point gain frequency of the control loop can be neglected because they are no longer relevant to the control loop's behavior.

[0094] Fig. Figure 12C illustrates a block diagram of an alternative equivalent circuit 1216, which includes an alternative transmission line model that includes a pi network 1220.

[0095] The alternative equivalent circuit 1216 comprises an ACU 1218, which applies a voltage to a sensor network 1214. The pi network 1220 includes a line inductance L, a line resistance R, and a line capacitance, which is distributed across the capacitors C. L2 and C L3 is distributed. Different transmission values ​​along the length of a communication bus component model deviations in the line length. In some embodiments, a blocking capacitor C is used. b within the ACU 1210 and the sensor network 1222, as well as a resistor connected in series with the blocking capacitor in the sensor network 1214, is taken into account.

[0096] It is desirable that the revealed characterization not be based on the one in Fig. 12B and Fig. The equivalent circuits illustrated in Section 12C are not limited. Rather, the illustrated transmission line models are not limiting models, and different equivalent circuit models can be used for the communication bus. For example, in some embodiments, an equivalent circuit model may include a T-network, or, for greater precision, implementations such as a transmission real line model based on the telegraph differential equation.

[0097] In some embodiments, the same functionality as an equivalent circuit can be achieved by using a transfer function model that describes the load of a sensor network with poles and zeros. This is because an ACU can be configured using information about the pole and zero distribution. For example, if the evaluation unit measures a transfer function or an impedance function with a periodic signal, it can also directly derive pole and zero distributions from the response.

[0098] In some embodiments, the functionality of a sensor network can be determined by incorporating internal transfer functions (e.g., of the control loop, the output driver stage, etc.) into the model. Such embodiments enable a precise characterization of the load when the internal analog components of the control loop exhibit manufacturing tolerances, temperature dependencies, or aging effects that have a non-negligible impact on the performance of the control loop.

[0099] Fig. Figure 13 is a block diagram of some additional embodiments of a vehicle sensor system 1300 comprising a sensor interface module 1302 configured to characterize a sensor network 212 and selectively adjust the operation of the sensor interface module 1302 based on the characterization.

[0100] The sensor interface module 1302 has a control interface 1304, which ensures networking with the controller 204, and a sensor interface 1306, which ensures networking with the wire pair 1308, 1310, which is coupled to the sensor network 212. Furthermore, the sensor interface module 1302 includes a reference voltage source 408, which is configured to provide a control signal S. CTRL received from the controller 204 in order to use it as the basis for a variable reference signal V ref to produce.

[0101] The reference voltage source 408 is coupled to a closed-loop control system 1312. In some embodiments, the closed-loop control system 1312 comprises a comparator 1314 and a PID (proportional-integral-derivative controller) 1316. The comparator 1314 (e.g., a comparator, an analog-to-digital converter) has a first input connected to the reference voltage source 408 and a second input configured to receive a feedback signal from the output node 1320. An output signal of the comparator 1314 is coupled to the input of the PID controller 1316, which is configured to receive a digital control signal D. PID This generates a voltage that drives the output driver stage 1322, regulating an output voltage at the output node 1320 so that it corresponds to the variable reference voltage V. ref fits.

[0102] An evaluation unit 1326 is configured to have access to the output node 1320, the output of the comparator 1314, and the control signal output of the PID controller 1316. Since the PID controller 1316 regulates the supply current using digitally controlled current sources, the PID controller output can be considered a measurement of this current.

[0103] It is desirable that the evaluation unit 1326 receive the test signal. Stest It regulates in multiple ways. In some embodiments, the evaluation unit 1326 can regulate current signals by changing the operating parameters S. par of the PID controller 1316. In some embodiments, the evaluation unit 1326 can generate current signals (current jumps, periodic current signals, random current) by directly adding a digital signal s dig to the digital control signal D PIDvia adder 1318 (e.g., to increase the current of the high-side source so that the output current is higher than the current drawn by the sensor).

[0104] The evaluation unit 1326 can be configured to take into account the response of other components of the sensor interface module 1302 when characterizing the sensor network 212. For example, in some embodiments, the output driver stage 1322 may include one or more low-pass filters 1324 located between the closed-loop control 1312 and the current sources 412 in the output driver stage 1322. The poles of the low-pass filters 1324 exhibit behavior that depends on the parameters of the MOS transistors, which have a significant manufacturing tolerance and a significant temperature dependence. Therefore, to accurately characterize the sensor network, the transfer function of the output driver stage 1322 can also be characterized along with the response of the sensor network 212.

[0105] To separate the evaluation of the internal and external transfer functions, for example, the evaluation unit 1326 can characterize the transfer function of the low-pass filter 1324 before normal bus operation begins. The transfer function of the low-pass filter 1324 can be determined based on its design or by performing additional system measurements. In some embodiments, the sensor interface module 1302 can incorporate a control resistor R. v include a resistor with a known resistance. By changing the value of the control resistor R v Measurements can be taken, initially to characterize the low-pass filter transfer function; subsequently, the evaluation unit 1326 can characterize the load impedance of the sensor network 212. Alternatively, changes in the value of the control resistor R can be measured. vThis can be done to influence the resonance behavior of the external network (e.g., to characterize the capacitive load with a higher resistance and then reduce the resistance to increase the Q-factor of a resonance in order to extract the inductance from the resonance frequency). In other embodiments, the sensor interface module 1302 can measure parameters at different frequencies to first characterize internal components and then to characterize the load impedance of the sensor network 212 based on the knowledge of the internal component. Fig. Figure 14 is a block diagram of an alternative embodiment of a disclosed sensor interface module 1400.

[0106] The sensor interface module 1400 includes an evaluation unit 1402, which can be configured to perform network characterization according to a number of different embodiments. It is desirable that the following embodiments are non-limiting embodiments that can be used to perform network characterization, and that additional embodiments or combinations of the following embodiments can be used.

[0107] In some embodiments, the evaluation unit 1402 can be configured to measure the response of a supply voltage to a slight increase in the supply current. Since the current consumption of sensors can be assumed to be constant for small changes in the supply voltage, a current delivered that is higher than the current consumed by the sensors causes a voltage rise at the output node. Therefore, by evaluating the rate of rise (e.g., the rising edge), information about the resonance (e.g., capacitance and inductance) can be obtained by characterizing the excess of delivered current that exceeds the actual current consumption of the sensors. For example, after an initial settling time, the rising edge of the supply voltage is inversely proportional to the sum of the capacitors in the sensor network.The initial oscillations, which can be observed immediately after the application of the current change, provide further information about the inductance and the distribution of the capacitors.

[0108] In some alternative embodiments, the evaluation unit 1402 can be configured to apply a voltage step to the reference voltage and measure the step response of the control loop that records the current and / or voltage. Information about the sensors (e.g., capacitance and inductance) can be obtained from the voltage and current readings.

[0109] In other alternative embodiments, the evaluation unit 1402 can be configured to stimulate the sensor network with a periodic signal and measure the gain and / or phase shift of the response. For example, the evaluation unit 1402 can include a periodic signal generator 1404 configured to produce a test signal that includes a periodic signal (e.g., a periodic sinusoidal signal). The evaluation unit 1402 is configured to characterize the response at different frequencies. At each frequency, the evaluation unit 1402 receives the amplitude and phase shift of a response. Therefore, each frequency measurement provides information that can be used to adjust an equivalent circuit.

[0110] In some embodiments, the periodic signal can be a sinusoidal signal. In such embodiments, the transfer function of the load network can be determined directly from the response. In other embodiments, the periodic signal can be simplified approximations of a sinusoidal signal, including triangular or rectangular signals. In some embodiments, the simplified approximations can be fitted by filters configured to remove unwanted harmonics.

[0111] In other alternative embodiments, the evaluation unit 1402 can be configured to stimulate the sensors with noise. For example, the evaluation unit 1402 can include a noise generator 1406 configured to produce a test signal containing noise (e.g., random or pseudorandom signals). The evaluation unit 1402 is configured to record the noise and the response (e.g., the injected disturbance current and the resulting voltage response, or noise generated in the supply voltage and the resulting induced current changes). Furthermore, the evaluation unit 1402 is configured to perform a spectral analysis of both the noise and the response by causing an FFT block 1408 to perform a fast Fourier transform of the noise and the response. The transfer function can be calculated as the quotient of both spectra.

[0112] In other alternative embodiments, the evaluation unit 1402 can be configured to induce a system-inherent oscillation of the voltage regulator and measure the oscillation period to determine the dominant parallel resonant frequency of the load. The system-inherent oscillations cause control instability, which reduces control stability (e.g., by increasing the frequency of the dominant pole). As the stability is gradually reduced, the oscillation occurs at the resonant frequency.

[0113] In some embodiments, the evaluation unit 1402 can be configured to generate system-inherent vibrations by reducing the value or even the sign of an emulated resistance R. vfrom "positive" to "negative". In other embodiments, the evaluation unit 1402 can be configured to induce system-inherent oscillations by adjusting the phase range of the closed control loop using the operating parameters S. par is changed. To avoid misinterpretation of the vibrations by the sensors, the vibration amplitude can be limited by adjusting the operating parameters S. parThe system is designed to initiate oscillations based on current or voltage feedback signals. It is understood that those skilled in the art will recognize equivalent modifications and / or alterations based on reading and / or understanding the description and accompanying drawings. The present disclosure includes all such modifications and alterations and is not intended to be limited in any way. Furthermore, if a particular feature or aspect has been disclosed with respect to only one of several implementations, this feature or aspect may optionally be combined with one or more other features or aspects of other implementations.To the extent that "includes," "has," "with," and / or variations of these terms are used in this document, they also implicitly include terms such as "comprises." Similarly, the term "exemplary" refers only to an example and not to the best. Furthermore, it should be understood that features, layers, and / or elements depicted in this document are presented with specific dimensions and / or orientations in relation to one another for the purpose of simplification and clarity, and that the actual dimensions and / or orientations may differ significantly from those illustrated in this document.

Claims

[1] Motor vehicle control (202, 302, 402, 702, 1002, 1210, 1218, 1302), comprising: a controller (204, 310, 406, 710) configured to selectively generate a plurality of control signals (sCTRL) corresponding to a plurality of different communication protocols, wherein the control signals (sCTRL) in question have properties corresponding to one of the plurality of different communication protocols; a modulation unit (208, 306) configured to receive one of the control signals (sCTRL) and to generate a modulated communication signal and transmit it via a communication bus (210) which has properties corresponding to a communication protocol of one of the control signals (sCTRL), wherein the communication signal for each of the plurality of different communication protocols is provided to the same communication bus (210); wherein the communication bus (210) is configured to provide the communication signal to a sensor network (212) comprising one or more sensors (212a...212n, 314, 316, 318). [2] Motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to claim 1, wherein one and the same sensor interface module (206, 304, 404, 706, 1004) comprising the control unit (204, 310, 406, 710) and the modulation unit (208, 306) is configured to selectively generate the plurality of different communication protocols comprising a Peripheral Sensor Interface 5 protocol (PSI5 protocol) and a Distributed System Interface 3 protocol (DSI3 protocol). [3] Motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to claim 1 or 2, wherein the motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302) comprises an airbag control unit configured to control the operation of one or more airbags within a motor vehicle. [4] Motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to claim 3, wherein the communication bus (210) comprises a two-wire communication bus comprising a first bus wire (210a) connected between the modulation unit (208, 306) and the sensor network (212) and a second bus wire (210b) connected between the modulation unit (208, 306) and the sensor network (212). [5] Motor vehicle control (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to one of claims 1-4, wherein the communication signal comprises voltage modulation. [6] Motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to any one of claims 1-5, further comprising: an evaluation unit (704, 1006, 1202, 1326, 1402) which is set up to send a test signal to the sensor network (212), to measure a response of the test signal induced by the sensor network (212) and to determine one or more characterization parameters of the sensor network (212) based on the measured response. [7] Motor vehicle control (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to claim 6, wherein the test signal comprises a voltage modulation having a voltage change value that is smaller than a voltage change value of a synchronization pulse, so that the test signal can characterize an impedance load of the sensor network (212) without receiving a data packet response. [8] Motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to claim 6 or 7, wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is configured to send the test signal during a time window in which no data communication takes place between the sensor network (212) and the motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302). [9] Motor vehicle control (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to one of claims 6-8, wherein the test signal comprises a voltage modulation having a synchronization pulse with properties corresponding to a first communication protocol, so that the test signal can be used to determine whether the first communication protocol is used by the sensor network (212). [10] Motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to claim 9, wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is configured to determine that the sensor network (212) uses the first communication protocol when a response to the first communication protocol is received from the sensor network (212); and wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is set up to determine that the sensor network (212) is not using the first communication protocol if the response to the first communication protocol is not received from the sensor network (212). [11] Motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302) according to claim 9 or 10, wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is configured to initially send a first test signal having a DSI3 synchronization pulse with an initially falling voltage, and subsequently send a second test signal having a PSI5 synchronization pulse with an initially rising voltage. [12] Sensor system (200, 300, 400, 700, 1000, 1300, 1400), comprising: a sensor interface module (206, 304, 404, 706, 1004) configured to generate a communication signal that is provided to a sensor network (212) comprising one or more sensors (212a...212n, 314, 316, 318); and An evaluation unit (704, 1006, 1202, 1326, 1402) configured to characterize the electrical behavior of the sensor network (212) by operating the sensor interface module (206, 304, 404, 706, 1004) to send the communication signal as a test signal to the sensor network (212), measuring a response to the test signal elicited by the sensor network (212), and determining one or more characterization parameters that describe the electrical behavior of the sensor network (212) based on the measured response, wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is configured to operate the sensor interface module (206, 304, 404, 706, 1004) based on the determined one to adjust characterization parameters or specific multiple characterization parameters to improve the performance of the sensor interface module (206, 304, 404, 706, 1004). [13] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to claim 12, wherein the determination (912) of the one or more characterization parameters is carried out by adapting an equivalent circuit, configured to model the sensor network (212), to the measured response. [14] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to claim 12 or 13, wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is configured to characterize the electrical behavior of the sensor network (212) using a synchronous bus mode by determining an open time window in which no data communication takes place between the sensor interface module (206, 304, 404, 706, 1004) and the sensor network (212), and sending the test signal within this open time window. [15] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to one of claims 12-14, wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is configured to operate the sensor interface module (206, 304, 404, 706, 1004) to generate the test signal as a modulated voltage which changes by a voltage value which is less than a minimum amplitude of a synchronization pulse of an associated communication protocol. [16] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to one of claims 12-14, wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is configured to operate the sensor interface module (206, 304, 404, 706, 1004) to generate the test signal as a modulated current by changing a supply current of the sensor interface module (206, 304, 404, 706, 1004). [17] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to one of claims 12-16, wherein the sensor interface module (206, 304, 404, 706, 1004) is configured to generate the communication signal according to a Peripheral Sensor Interface 5 communication protocol (PSI5 protocol). [18] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to one of claims 12-17, wherein one or more characterization parameters comprise a complex impedance of an impedance load of the sensor network (212), one or more components of an equivalent circuit describing the impedance load, or one or more components of a transfer function describing the impedance load. [19] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to one of claims 12-18, wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is configured to adapt the operation of the sensor interface module (206, 304, 404, 706, 1004) on the basis of one or more characterization parameters obtained from a plurality of temporally separated characterization operations. [20] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to any one of claims 12-19, further comprising: a controller (204, 310, 406, 710) configured to operate the sensor interface module (206, 304, 404, 706, 1004), optionally generating a plurality of control signals (sCTRL) corresponding to a plurality of different communication protocols, wherein the control signals (sCTRL) in question have properties corresponding to one of the plurality of different communication protocols; and wherein the sensor interface module (206, 304, 404, 706, 1004) is configured to receive one of the control signals (sCTRL) and to generate the test signal to have properties that correspond to a communication protocol of one of the control signals (sCTRL). [21] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to claim 20, wherein the test signal comprises a voltage modulation having a synchronization pulse with properties corresponding to a first communication protocol, so that the test signal can be used to determine whether the first communication protocol is used by the sensor network (212). [22] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to claim 21, wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is configured to determine that the sensor network (212) uses the first communication protocol when a response to the first communication protocol is received from the sensor network (212); and wherein the evaluation unit (704, 1006, 1202, 1326, 1402) is set up to determine that the sensor network (212) is not using the first communication protocol if the response to the first communication protocol is not received from the sensor network (212). [23] Sensor system (200, 300, 400, 700, 1000, 1300, 1400) according to one of claims 20-22, wherein the plurality of different communication protocols comprises a Peripheral Sensor Interface 5 protocol (PSI5 protocol) and a Distributed System Interface 3 protocol (DSI3 protocol). [24] Method (800) for demonstrating a communication protocol used by sensors (212a...212n, 314, 316, 318) connected to a motor vehicle control system (202, 302, 402, 702, 1002, 1210, 1218, 1302), the method comprising: Selectively generating a plurality of control signals (sCTRL) corresponding to a plurality of different communication protocols, wherein the control signals (sCTRL) in question have properties corresponding to one of the plurality of different communication protocols; generating a test signal comprising a modulated communication signal having properties corresponding to a communication protocol of one of the control signals (sCTRL), and transmitting the communication signal via a communication bus (210); wherein the communication signal for each of the plurality of different communication protocols is provided to the same communication bus (210); and Providing the communication signal for a sensor network (212) comprising one or more sensors (212a...212n, 314, 316, 318) via the communication bus (210). [25] Method (800) according to claim 24, wherein the plurality of different communication protocols comprises a Peripheral Sensor Interface 5 protocol (PSI5 protocol) and a Distributed System Interface 3 protocol (DSI3 protocol). [26] Method (800) according to claim 24 or 25, wherein the test signal comprises a voltage modulation having a synchronization pulse with properties corresponding to a first communication protocol, so that the test signal can be used to determine whether the first communication protocol is used by the sensor network (212). [27] Method (900) for characterizing the electrical behavior of a sensor network (212), comprising: Providing (902) a motor vehicle control unit (202, 302, 402, 702, 1002, 1210, 1218, 1302) comprising a sensor interface module (206, 304, 404, 706, 1004) connected to a sensor network (212) comprising one or more sensors (212a...212n, 314, 316, 318); Generating (906) a test signal based on one or more controller parameters; sending (908) the test signal to the sensor network (212); measuring a response of the test signal caused by the sensor network (212); Determine (912) one or more characterization parameters based on the measured response that describe the electrical behavior of the sensor network (212); and Adapting (914) the operation of the sensor interface module (206, 304, 404, 706, 1004) based on one or more characterization parameters to improve the performance of the sensor interface module (206, 304, 404, 706, 1004). [28] Method (900) according to claim 27, wherein the test signal comprises a modulated voltage which changes by a voltage value which is less than a minimum amplitude of a synchronization pulse of an associated communication protocol. [29] Method (900) according to claim 27, wherein the test signal comprises a modulated current. [30] Method (900) according to one of claims 27-29, wherein the operation of the sensor interface module (206, 304, 404, 706, 1004) is adapted on the basis of one or more characterization parameters obtained from a plurality of temporally separated characterization operations.

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