JP4918506B2 - Load control device - Google Patents

Description

  The present invention relates to a load control device that controls various loads by superimposing a control signal on a power line using an ASK method.

  For example, loads such as various motors and lamps mounted on the vehicle are connected to an ECU (Electronic Control Unit) by a wire harness, and electric power is supplied from the ECU to control driving and stopping. In addition, in order to transmit electric power and transmit control signals between a plurality of ECUs mounted on a vehicle, a control signal is superimposed on a power line connecting the ECUs, thereby reducing the number of harnesses. A PLC (Power Line Communication) communication method capable of transmitting both power and control signals has been proposed and put into practical use.

  In the PLC communication system, a control signal is converted to a high-frequency signal corresponding to “0” and “1” by ASK (Amplitude Shift Keying) modulation, and this signal is superimposed on a power transmission power line, and power and Send a control signal. Then, the PLC circuit and control unit provided in the ECU on the receiving side demodulates and samples the control signal superimposed on the power supply line, and controls the driving of the load based on the sampling result.

  However, for example, when the load is a DC motor, periodic impulse noise is generated as the motor rotates, and this impulse noise may be superimposed on the power supply line. The impulse noise may cause an error in the control signal composed of “0” and “1”. In the ECU on the receiving side, for example, the signal that was originally “0” is “1”. The problem of false detection occurs. Therefore, in order to solve the above problem, for example, a technique disclosed in Japanese Patent Laid-Open No. 2006-270416 (Patent Document 1) has been proposed.

In Patent Document 1, one bit of a control signal superimposed on a power supply line is sampled a plurality of times (for example, four times) by a receiving ECU, and the occurrence of impulse noise is detected by a noise detector. At the time of detecting the impulse noise, the sampling data in the impulse noise detection period is invalidated, and the control signal is corrected based on the sampling data when no impulse noise is generated. For example, if the sampling data of 3 times among the sampling data of 4 times for the 1-bit control signal is affected by the impulse noise, the remaining sampling data (not affected by the impulse noise) Based on the sampling data), a method of correcting the 1-bit control signal to avoid the influence of impulse noise is employed.
JP 2006-270416 A

  However, in the conventional example disclosed in Patent Document 1 described above, it is assumed that the duration of the impulse noise is shorter than the time of 1 bit of the control signal, and the impulse noise is continued longer than the time of 1 bit. When this occurs, the control signal cannot be corrected. In other words, the ECU on the receiving side performs four times of data sampling with respect to a 1-bit control signal transmitted while being superimposed on the power line, and impulse noise continues during the four times of data sampling. If it occurs, the 1-bit control signal cannot be corrected.

  The present invention has been made in order to solve such a conventional problem, and an object of the present invention is to appropriately generate an error in a control signal even when impulse noise is generated for a long time. An object of the present invention is to provide a load control device capable of correcting.

  In order to achieve the above object, according to the first aspect of the present invention, power is supplied through a power line and is superimposed on the power line using the ASK method. In a load control apparatus that receives a control signal having a checksum bit and controls a load, the control signal is detected by performing data sampling a plurality of times for one bit of the control signal superimposed on the power supply line Control signal detection means, noise detection means for detecting noise superimposed on the power supply line, and noise are continuously detected by the noise detection means over the plurality of data sampling times for one bit of the control signal. In this case, a bit data correcting means for correcting the 1-bit data based on the checksum bit is provided.

  According to a second aspect of the present invention, in the case where noise is detected by the noise detection unit after the plurality of times of data sampling for one bit of the control signal is started, the bit data correction unit The data sampled before noise is detected between 1 bit is assumed to be this 1-bit data, and the noise detection means until the plurality of times of data sampling for 1 bit of the control signal are completed. When noise is detected by the above, data sampled after the detection of noise between the 1 bit is completed is the 1-bit data.

  The invention according to claim 3 is characterized in that the load is a load mounted on a vehicle, and the electric power supplied via the power line is supplied from a battery mounted on the vehicle. And

  In the invention of claim 1, when receiving a control signal (transmission data) transmitted superimposed on the power line, sampling is performed a plurality of times (for example, four times) for one bit of the control signal, When impulse noise occurs continuously over the entire sampling time performed for one bit of transmission data, a transmission error is corrected by using a checksum bit. Therefore, even when continuous impulse noise occurs, highly accurate PLC communication can be performed.

  In the second aspect of the present invention, when the occurrence of impulse noise is detected in the middle of sampling that is executed a plurality of times, the data at the time of sampling immediately before that is used as the received data of the bit and is executed a plurality of times. When detection of impulse noise is completed during sampling, the data immediately after that is used as received data for that bit. Therefore, highly accurate PLC communication can be performed both when the duration of the impulse noise is shorter than one bit of the control signal and when the duration is longer.

  In invention of Claim 3, since loads, such as a motor, a lamp | ramp, and a horn mounted in a vehicle, are controlled, various instrumentation equipment mounted in a vehicle can be controlled with high precision.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing a configuration in which a plurality of ECUs (load control devices) are arranged in a vehicle. As shown in FIG. 1, four ECUs 10a to 10d and a battery 21 are provided in the vehicle 100, and the ECUs 10a to 10d and the battery 21 are connected via a power line L1. Accordingly, each of the ECUs 10a to 10d is driven by electric power supplied from the battery 21 via the power supply line L1.

  Moreover, between each ECU10a-10d, a control signal (henceforth "transmission data") is transmitted / received by PLC (Power Line Communication) communication system. That is, in the ECU on the transmission side (for example, the ECU 10a), the transmission data is modulated into signals indicated by “0” and “1” by the ASK method and superimposed on the power supply line L1, and the ECU on the reception side (for example, the ECU 10a, for example) The ECU 10b) extracts power and transmission data from a signal transmitted through the power line L1, and drives or stops the rearview mirror driving motor or power window driving motor, or turns on / off the illumination, sounds the horn, etc. To control.

  FIG. 2 is a block diagram illustrating a configuration of an ECU that is a load control device according to an embodiment of the present invention. FIG. 2 shows the configuration of the ECU 10b as an example of the ECU. The ECU 10b is composed of, for example, a microcomputer. The other ECUs 10a, 10c, and 10d have the same configuration.

  As shown in FIG. 2, the ECU 10b detects an impulse noise generated in the power line L1, an impulse noise detector (noise detecting means) 11, a PLC circuit 12, and a PLC signal level of transmission data superimposed on the power line L1. An impedance element 13 for preventing attenuation and removing a PLC signal to the circuit power supply side, a circuit power supply unit 14 for generating a DC voltage of a desired level from the DC power transmitted via the power supply line L1, and a control unit 15 And.

  The PLC circuit 12 includes a filter unit 121 that extracts a signal having a frequency in a desired band, a receiving unit 122, and a transmitting unit 123. When receiving data, the PLC circuit 12 starts from “0” and “1” transmitted via the power line L1. ASK demodulation is performed on the transmission data. At the time of data transmission, the ASK system is used to modulate transmission data into high-frequency signals corresponding to “0” and “1”, and a process of superimposing the modulated transmission data on the power supply line L1 is executed.

  The control unit 15 processes the transmission data received by the PLC circuit 12 based on the generation timing of the impulse noise detected by the impulse noise detection unit 11. Specifically, sampling is performed a plurality of times (for example, four times) for one bit of transmission data, and when the occurrence of impulse noise is detected during the sampling of the plurality of times, the impulse noise is detected. The data sampled immediately before the occurrence is detected is the reception data of this bit, and when the impulse noise detection is completed in the middle of a plurality of samplings, the data sampled immediately after that is the reception data of that bit, Further, when impulse noise is continuously generated over a plurality of sampling times performed for one bit of transmission data, the transmission data is corrected and determined by using a checksum bit. Process. And various loads, such as a motor and a lamp, are controlled based on the demodulated transmission data.

  That is, the control unit 15 has a function as a control signal detecting unit that performs data sampling a plurality of times for one bit of transmission data superimposed on the power supply line L1, and detects transmission data. When impulse noise is continuously detected over a plurality of data sampling times for a plurality of times, the bit data correcting unit corrects the 1-bit data based on the checksum bit.

  FIG. 3 is a flowchart showing a processing procedure of the ECU 10b which is the load control apparatus according to the present embodiment, and FIG. 4 is a timing chart showing each waveform when impulse noise longer than one bit period of transmission data occurs. Reference numeral 5 is a timing chart showing waveforms when impulse noise shorter than a 1-bit period of transmission data is generated, and the processing operation of the ECU 10b will be described below with reference to FIGS.

  When power is supplied to the ECU 10b via the power line L1, transmission data superimposed on the power line L1 is taken out by the filter unit 121 of the PLC circuit 12 and received by the receiving unit 122. Here, the transmission data is a signal indicated by “0” and “1” as shown in FIG. Further, as shown in FIG. 4B, the PLC waveform received by the receiving unit 122 of the PLC circuit 12 has an amplitude when the transmission data is “0”, and an amplitude when the transmission data is “1”. The waveform does not occur. Further, when impulse noise occurs, the impulse noise is superimposed on the power supply line L1 as shown in FIG. As a result, the PLC circuit 12 receives both the PLC waveform and the impulse noise as shown in FIG.

  The control unit 15 performs sampling a plurality of times (in this example, four times) for one bit of the reception signal received by the reception unit 122 (step S11 in FIG. 3). That is, as shown in FIG. 4E, four samplings are performed for one bit of transmission data. Therefore, when impulse noise is not superimposed and one bit of transmission data is “0”, all four samplings are “0”, and one bit of transmission data is “1”. The four samplings are all “1”.

  Next, the control unit 15 recognizes the generation timing and duration of the impulse noise based on the detection result by the impulse noise detection unit 11 (see step S12, FIG. 4F). Then, it is determined whether or not impulse noise is detected (step S13).

  When it is determined that no impulse noise is generated (NO in step S13), the control unit 15 controls various loads based on the received data instruction (step S21). On the other hand, when determining that the impulse noise is generated (YES in step S13), the control unit 15 determines whether the impulse noise is generated in the middle of one bit of the transmission data ( Step S14). That is, it is determined whether impulse noise has been generated since the sampling of the second transition out of four samplings executed for one bit of transmission data or whether impulse noise has been generated since the first sampling. To do.

  When it is determined that the impulse noise is generated in the middle of one bit of the transmission data (YES in step S14), the control unit 15 converts the sampling data before the detection of the impulse noise into the one bit. It is assumed that it is data (step S15). That is, when the occurrence of impulse noise is detected at time t1 shown in FIG. 4 (f), 2 out of the four samplings performed on the bit indicated by the symbol “A” in FIG. 4 (a). Since the impulse noise has been generated since the sampling after the first time, the sampling data before the detection of the impulse noise, that is, the first sampling data is adopted as the data of this bit “A”. That is, the transmission data “1” can be correctly received.

  On the other hand, when it is not determined that the impulse noise is generated in the middle of one bit of the transmission data (NO in step S14), the control unit 15 generates the impulse noise until the middle of one bit of the transmission data. It is determined whether or not it has been (step S16). That is, of the sampling executed four times for one bit of transmission data, the generation of the impulse noise is completed before the fourth sampling is performed, or the generation of the impulse noise is continued until the fourth sampling. It is determined whether it is done.

  If it is determined that the impulse noise has occurred up to the middle of one bit of the transmission data (YES in step S16), the control unit 15 uses the sampling data after detection of the impulse noise as the one-bit data. It is assumed (step S17). That is, when the detection of the impulse noise is completed at time t2 shown in FIG. 4 (f), the fourth sampling among the four samplings performed on the bit indicated by the symbol “C” in FIG. 4 (a). Since the detection of the impulse noise is completed at the time before the sampling is performed, the sampling data after the impulse noise is detected, that is, the fourth sampling data is adopted as the data of the bit “C”. That is, the transmission data “1” can be correctly received.

  If it is not determined that the impulse noise has occurred up to the middle of one bit of the transmission data (NO in step S16), it is determined whether or not the impulse noise is detected in the entire one bit of the transmission data ( In step S18), when it is determined that impulse noise is detected in one bit of the transmission data (YES in step S18), a process of comparing the data bit and the checksum bit is performed (step S19). . Hereinafter, the checksum bit will be described with reference to FIG.

  As shown in FIG. 6, data to be transmitted using the ASK method is composed of a head bit, a data bit A, a data bit B, a checksum bit, and an end bit as shown in FIG.

  The data bit A is data including ID information indicating a transmission source and a transmission destination, and is, for example, 4-bit data “0010”.

  The data bit B is data including control information, and is, for example, 8-bit data “01001110”.

  The checksum bit is set as data obtained by inverting the data obtained by adding the data bit A and the data bit B. That is, when “0010” of data bit A and “01001110” of data bit B are added, it becomes “01010000” (this is referred to as “data a”), and when this is inverted, “10101111” is obtained. This “10101111” is the checksum bit. Therefore, adding the checksum bit and the above data a results in “11111111” (this is referred to as “data b”), and if this addition result is not obtained, an error has occurred in any of the bits. Become.

  In the process of step S19 in FIG. 3, it is determined whether or not an error has occurred in the received data by monitoring the data b. If an error has occurred, the received data is corrected ( Step S20). That is, when impulse noise is superimposed on all four samplings performed on one bit of transmission data, the received data is corrected using checksum bits.

  For example, when impulse noise is generated over the entire period of the bit indicated by “B” in the transmission data shown in FIG. 4A, the transmission data is originally “1”, although the transmission data is “1”. As shown in 4 (e), all the data received by four samplings are “0”. Therefore, correct received data “1” can be obtained by using the checksum bit.

  Thus, as shown in FIG. 4 (h), the transmission data shown in FIG. 4 (a) can be accurately received even when impulse noise longer than one bit of the transmission data occurs.

  Further, as shown in FIG. 5, when the generation time of impulse noise is shorter than the reception time of 1 bit of transmission data, all four samplings performed for 1 bit are affected by the impulse noise. There is nothing. That is, when the impulse noise as shown in FIG. 5C occurs, the second to fourth sampling data out of the four samplings executed by the bit indicated by the code “D” of the transmission data is the impulse. It is affected by noise, and the first sampling data is correct data. Therefore, even when impulse noise shorter than the 1-bit reception time of transmission data occurs, accurate reception data that is not affected by the impulse noise is obtained by the processing of steps S15 and S17 shown in FIG. be able to.

  Thus, in the load control device according to the present embodiment, when receiving a control signal (transmission data) superimposed on the power supply line L1, a plurality of times (for example, one bit of the transmission data (for example, (4 times) sampling is performed, and if the occurrence of impulse noise is detected during the sampling of the plurality of times, the data at the time of sampling immediately before that is used as the received data of the bit. In addition, when the detection of impulse noise is completed in the middle of a plurality of samplings, the data immediately after that is used as the reception data of the bit, and further, the sampling time of a plurality of times performed for one bit of the transmission data. When impulse noise occurs continuously throughout the entire transmission error is corrected by using a checksum bit.

  Therefore, even when impulse noise that lasts longer than the 1-bit reception time of transmission data is generated and superimposed on the power supply line L1, it occurs in transmission data that is transmitted superimposed on the power supply line L1. Since the error can be corrected, the transmission data transmitted from the other ECU 10a can be accurately received.

For this reason, the reliability of PLC communication can be improved, the number of communication application sites in the vehicle can be increased, the number of parts can be reduced, and the vehicle can be reduced in weight, size and space. Can be achieved. For this reason, it contributes to improvement in fuel consumption, energy saving, and resource saving. As described above, the load control device of the present invention has been described based on the illustrated embodiment, but the present invention is not limited to this, and the configuration of each part Can be replaced with any configuration having a similar function.

  For example, in the above-described embodiment, the example of controlling the load mounted on the vehicle has been described. However, the present invention is not limited to this, and includes a configuration for controlling the load using another PLC communication method. It can be applied to a circuit.

  This is extremely useful in avoiding the influence of impulse noise when transmitting and receiving control signals using the PLC method.

It is explanatory drawing which shows the connection state of the load control apparatus (ECU) which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of the load control apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows the processing operation of the load control apparatus which concerns on one Embodiment of this invention. 4 is a timing chart showing waveforms when impulse noise longer than one bit period of transmission data is generated in the load control device according to the embodiment of the present invention. 6 is a timing chart illustrating waveforms when impulse noise shorter than one bit period of transmission data occurs in the load control device according to the embodiment of the present invention. It is explanatory drawing of the checksum bit used in the load control apparatus which concerns on one Embodiment of this invention.

Explanation of symbols

10a to 10d ECU (load control device)
11 Impulse noise detector (noise detection means)
DESCRIPTION OF SYMBOLS 12 PLC circuit 13 Impedance element 14 Circuit power supply part 15 Control part 121 Filter part 122 Reception part 123 Transmission part L1 Power supply line 21 Battery

Claims (3)

A load is controlled by receiving a control signal composed of “0” and “1” and having a checksum bit that is supplied with power through the power supply line and superimposed on the power supply line using the ASK method. In the load control device,
Control signal detection means for performing data sampling a plurality of times for one bit of the control signal superimposed on the power supply line and detecting the control signal;
Noise detecting means for detecting noise superimposed on the power line;
A bit that corrects this 1-bit data based on the checksum bit when noise is continuously detected by the noise detection means throughout the plurality of data sampling times for one bit of the control signal. Data correction means;
A load control device comprising: The bit data correcting means detects the noise between the bits when the noise detecting means detects noise after the data sampling is started a plurality of times for one bit of the control signal. It is assumed that the data sampled before
If noise is detected by the noise detection unit until the data sampling for one bit of the control signal is completed, the sampled data after the detection of noise between the bits is completed. 2. The load control device according to claim 1, wherein the load control device is one-bit data.   3. The load according to claim 1, wherein the load is a load mounted on a vehicle, and the electric power supplied via the power line is supplied from a battery mounted on the vehicle. The load control device according to any one of the above.

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