Method and apparatus for conducting data communications - Patents.com
By phase shifting signal pulse trains across multiple communication paths in vehicle data communication systems, the method addresses the challenge of managing EMC emissions, achieving reduced radiation characteristics and improved EMC compatibility.
Patent Information
- Application Number
- JP2024554628
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-03-14
- Filing Date
- 2023-03-14
- Publication Date
- 2025-04-11
AI Technical Summary
Current vehicle data communication systems face challenges in managing electromagnetic compatibility (EMC) emissions, particularly when multiple communication paths are used, leading to increased EMC load and limited effectiveness of EMC reduction measures.
The method involves using signal pulse trains with rising edges of equal repeating frequencies for communication between a controller and units, where the signal pulse trains are phase shifted across different communication paths to avoid simultaneous rising edges, thereby reducing EMC emissions.
This approach effectively suppresses EMC emissions by preventing the overlap of radiant energy through phase shifting of signal pulse trains, thus reducing the radiation characteristics of the communication system.
Smart Images
Figure 2025509506000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a method and a device for data communication between a control device and a number of units in a vehicle, which units can in particular be sensors and / or actuators, in other words for a bidirectional data exchange via at least two communication buses (such as DSI3) to which one control device (master) and one or more functional units (slaves) are respectively connected. [Background technology]
[0002] In a vehicle, the various units of a subsystem, such as an ultrasonic (US) measurement system for parking assistance, are generally connected to a control device via a communication bus. However, in current ultrasonic systems, for faster data transmission (due to parallelization), each ultrasonic transducer is connected to the control device via a separate communication line.
[0003] For data communication, signals are typically modulated in the form of signal pulse trains. When modulating signals, EMC emissions inevitably occur. If several communication buses or lines are connected in parallel and are conventionally grouped together at least in wiring sections in a distribution cable harness, the load due to EMC emissions increases. To deal with this, measures are taken to reduce EMC, but if the EMC load is too high, the effect may be limited or require a lot of effort. Summary of the Invention [Problem to be solved by the invention]
[0004] The present invention aims to provide a method and device for performing data communication in a vehicle, which method and device suppress additional EMC emissions even when multiple communication paths are used. [Means for solving the problem]
[0005] In order to achieve the above object, the present invention proposes a method for data communication between a control device and a number of units in a vehicle, which units may be sensors and / or actuators, comprising: There are a plurality of communication paths, and at least one unit is communicatively connected to the control device via each of these communication paths; communication between said control device and said unit is effected by transmitting a signal pulse train consisting of pulses with equal rising edges of repetition frequency, the signal pulse trains transmitted from the control device via at least two of the communication paths to the units in communication therewith are phase shifted relative to one another so that the rising edge of one of the transmitted signal pulse trains has a time offset with respect to the rising edges of the pulses of all other transmitted signal pulse trains within a period determined by the repetition frequency, and / or this also applies to the falling edges of the pulses; and / or The slope of the rising edge of one of the pulses in the signal pulse train is selected to be different from the slopes of the rising edges of all other of the pulses in the signal pulse train.
[0006] The idea pursued by the invention is to use signal pulse trains with pulses having rising edges of equal repetition frequency for communication between the control device and the units. The control device transmits these signal pulse trains with a phase shift over the respective communication paths, so that the rising edges of the pulses of the two signal pulse trains are prevented from occurring simultaneously, and preferably the same also for the falling edges. This reduces the strength of the EMC emissions.
[0007] Typically, the above units will send "unique" signal pulse trains to the control device in response to the phase-shifted signal pulse train of the present invention output from the control device, but the above description of the control device's signal pulse trains also applies to these response signal pulse trains.
[0008] The unit may for example comprise an ultrasonic transducer which can be used to monitor the surroundings of the vehicle. The present invention relates to the communication between the controller and the unit, and not to the emitted ultrasonic signal and the echo signal reflected from objects around the vehicle.
[0009] As the communication paths, data communication buses such as DSI3, which are well known in the prior art, can be used, in which case the data communication bus is a bidirectional bus.
[0010] In accordance with the present invention, the above-described modulation reduces the radiation signature of the communication system, and the phase shift in transmitting the individual signal pulse trains reduces the overlap of radiated energy.
[0011] As an alternative, or in addition to a phase shift, the slopes of the rising edges of the pulses in the signal pulse train may be selected to be different.
[0012] In a useful development of the invention, the signal pulse trains transmitted via the same communication channel may be phase shifted relative to one another so that the rising edge of one of the pulses of the transmitted signal pulse train has a time offset with respect to the rising edges of the pulses of all other transmitted signal pulse trains within the period of the repetition frequency and / or the slope of the rising edge of one of the pulses of the signal pulse train may be selected to be different from the slope of the rising edges of the pulses of all other signal pulse trains.
[0013] In another useful development of the invention, only one unit may be communicatively connected to the control device via at least some of the communication paths or via each communication path, respectively.
[0014] In a preferred embodiment of the present invention, at least a part of the communication paths or each of the communication paths may be formed as a bus to which a plurality of units are connected.
[0015] In another preferred embodiment of the present invention, the communication paths may each be an electrical wiring, particularly a cable.
[0016] In a useful development of the invention, the electrical wiring may be grouped at least in sections.
[0017] According to the present invention, the above object is also achieved by an apparatus for data communication between a control device and a plurality of units in a vehicle, the units being sensors and / or actuators, the apparatus comprising: A control unit; A plurality of communication paths; a plurality of units, which may be sensors and / or actuators; At least one unit is communicatively connected to the control device via each communication path; said control device transmitting to said unit a signal pulse train consisting of pulses with equal rising edges and repetition frequency for data communication with said unit; the signal pulse trains transmitted from the control device via at least two of the communication paths to the units in communication therewith are phase shifted relative to one another so that the rising edge of one of the transmitted signal pulse trains has a time offset with respect to the rising edges of the pulses of all other transmitted signal pulse trains within a period determined by the repetition frequency, and / or this also applies to the falling edges of the pulses; and / or The slope of the rising edge of one of the pulses in the signal pulse train is selected to be different from the slopes of the rising edges of all other of the pulses in the signal pulse train.
[0018] In a useful development of the invention, the signal pulse trains transmitted via the same communication channel may be phase shifted relative to one another so that the rising edge of one of the pulses of the transmitted signal pulse train has a time offset with respect to the rising edges of the pulses of all other transmitted signal pulse trains within the period of the repetition frequency and / or the slope of the rising edge of one of the pulses of the signal pulse train may be selected to be different from the slope of the rising edges of the pulses of all other signal pulse trains.
[0019] In a preferred embodiment of the present invention, only one unit may be communicatively connected to the control device via at least some of the communication paths, or via each communication path.
[0020] In another useful development of the invention, at least some of the or each communication path can be configured as a bus to which several units are connected.
[0021] In another preferred embodiment of the present invention, each communication path is formed as an electric wiring, particularly a cable, and the electric wiring may be grouped at least for each portion.
[0022] Hereinafter, the present invention will be described in detail using embodiments with reference to the drawings. [Brief description of the drawings]
[0023] [Figure 1] FIG. 1 shows an embodiment of a data communications system having four independent communication paths between a controller and four individual units that are individually controlled by the controller. [Diagram 2]FIG. 2 is a diagram showing an example of four signal pulse trains for the control device to control four units. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] 1 shows very diagrammatically a data communication system 10 comprising a control device 12 and, in this embodiment, four controlled units 14, 16, 18, 20, formed for example as sensors or actuators, which are controllable via individual communication paths 22, 24, 26 and 28 and which return signals to the control unit 12 via these paths. Examples of embodiments of the units 14 to 20 are, for example, ultrasonic transducers which can be mounted in the front and rear bumpers of a vehicle.
[0025] Phase-shifted control or data communication between the control unit 12 and the four units 14 to 20 by means of signal pulse trains of pulses with equal rising edges of repetition frequency is shown in Fig. 2. References 22', 24', 26', 28' in Fig. 2 refer to signal trains transmitted by the control unit 12 to the units 22, 24, 26, 28. In this embodiment, the signal pulse trains are different, but they may have the same pulse train. It can be seen that at any time, no pulses 30 with simultaneously occurring rising edges 32 are transmitted over the four communication paths 22 to 28 (see the time offsets Δt1, Δt2 and Δt3 of the signal pulse trains 24', 26' and 28' with respect to the signal pulse train 22'). And the feedback signals of each of the thus controlled units 14 to 20 are also shifted in time, so that at any time, no rising edges occur simultaneously on the four communication paths.
[0026] Additionally or alternatively, the slopes of the rising edges of the individual signal pulse trains can be selected to be different, which, like the phase shift control described above, also offers the advantage of not generating additional radiated energy and reducing the effort of EMC protection measures. [Explanation of symbols]
[0027] 10 Data Communication Systems 12 Control device 14 units 16 units 18 units 20 units 22 Communication Channel 24 Communication Channel 26 Communication Channel 28 Communication Channel 22' Signal Pulse Train 24' Signal Pulse Train 26' Signal Pulse Train 28' Signal Pulse Train 30 Pulse 32 rising edge
Claims
1. 1. A method for data communication between a control device and a plurality of units in a vehicle, the units being sensors and / or actuators, comprising: a plurality of communication paths (22 to 28) exist, and at least one unit (14 to 20) is communicatively connected to the control device (12) via each of these communication paths; communication between said control device (12) and said units (14 to 20) is effected by transmitting a signal pulse train (22' to 28') consisting of pulses (30) with equal rising edges (32) of repetition frequency, wherein the signal pulse trains (22' to 28') transmitted from the control device (12) to the units (14 to 20) in communication with them via at least two of the communication paths (22 to 28) are phase shifted relative to one another, so that the rising edge (32) of one of the pulses (30) of the transmitted signal pulse trains (22' to 28') has a time offset with respect to the rising edges (32) of the pulses (30) of all other transmitted signal pulse trains (22' to 28') within a period determined by the repetition frequency.
2. 2. The method according to claim 1, characterized in that the signal pulse trains (22' to 28') transmitted from the control device (12) to the units (14 to 20) via the same communication path (22 to 28) are phase shifted with respect to one another, so that the rising edge (32) of one of the transmitted signal pulse trains (22' to 28') has a time offset with respect to the rising edges (32) of the pulses (30) of all other transmitted signal pulse trains (22' to 28') within the period of the repetition frequency.
3. 3. The method according to claim 1 or 2, characterized in that only one unit (14 to 20) is in communication with the control device (12) via at least some of the communication paths (22 to 28), or via each communication path (22 to 28), respectively.
4. 3. The method according to claim 1 or 2, characterized in that at least some of the or each of the communication paths (22 to 28) is formed as a bus to which several units (14 to 20) are connected.
5. 6. The method according to claim 1, wherein said communication paths (22 to 28) are selected to be electrical wiring, in particular cables.
6. 6. The method of claim 5, wherein said electrical wiring is grouped at least in sections.
7. An apparatus for data communication between a control device and a plurality of units in a vehicle, the units being sensors and / or actuators, the apparatus comprising: A control unit (12); A plurality of communication paths (22 to 28); a plurality of units (14 to 20), which may be sensors and / or actuators; At least one unit (14 to 20) is in communication with the control device (12) via each communication path (22 to 28); said control device (12) transmitting to said units (14 to 20) signal pulse trains (22' to 28') consisting of pulses (30) having rising edges (32) of equal repetition frequency for data communication with said units (14 to 20); The signal pulse trains (22' to 28') transmitted from the control device (12) to the units (14 to 20) in communication with them via at least two of the communication paths (22 to 28) are phase shifted with respect to one another, so that the rising edge (32) of one of the pulses (30) of the transmitted signal pulse trains (22' to 28') has a time offset with respect to the rising edges (32) of the pulses (30) of all other transmitted signal pulse trains (22' to 28') within a period determined by the repetition frequency.
8. 8. The device according to claim 7, characterized in that the signal pulse trains (22' to 28') transmitted from the control device (12) to the units (14 to 20) via the same communication channel (22 to 28) are phase shifted with respect to one another, so that the rising edge (32) of one of the pulses (30) of the transmitted signal pulse trains (22' to 28') has a time offset with respect to the rising edges (32) of the pulses (30) of all other transmitted signal pulse trains (22' to 28') within the period of the repetition frequency.
9. 9. The device according to claim 7 or 8, characterized in that only one unit (14 to 20) is in communication with the control device (12) via at least some of the communication paths (22 to 28) or via each communication path (22 to 28), respectively.
10. 9. An apparatus as claimed in claim 7 or 8, characterized in that at least some of the or each of the communication paths (22 to 28) is formed as a bus to which several units (14 to 20) are connected.
11. 11. The device according to claim 7, wherein each communication path (22 to 28) is formed as an electrical line, in particular a cable.
12. 12. The device according to claim 11, wherein the electrical wiring is grouped at least in sections.