WO2016068188A1

WO2016068188A1 - Communication system

Info

Publication number: WO2016068188A1
Application number: PCT/JP2015/080381
Authority: WO
Inventors: 金澤　昭義; 淳 ▲高▼橋; 一男杉村; 崇明伊澤
Original assignee: 矢崎総業株式会社
Priority date: 2014-10-29
Filing date: 2015-10-28
Publication date: 2016-05-06

Abstract

In the present invention, a slave control device (4) receives a communication signal from a master control device (2), and controls loads (31, 32) in accordance with the received communication signal. A modulation unit (6) superimposes a communication signal from the master control device (2) onto power source lines (L2, L3), and a demodulation unit (7) demodulates and supplies to the slave control device (4) the communication signal superimposed on the power source lines (L2, L3). The modulation unit (6) is disposed on the battery (B) side above the power source lines (L1-L3), and the demodulation unit (7) is disposed on the load (31, 32) side above the power source lines (L1-L3). The modulation unit (6) superimposes a communication signal on the power source lines (L2, L3) closer to the load (31, 32) side than the modulation unit for the power source lines (L1-L3).

Description

Communications system

The present invention relates to a communication system, and more particularly to a communication system that performs communication using a PLC (Power Line Communication) system.

Conventionally, a PLC type communication system in which communication is performed via a power line is known. As an example in which this PLC communication system is mounted on a vehicle, for example, the one shown in FIG. 11 is known. As shown in the figure, a conventional communication system 100 includes a CPU 102 that transmits a communication signal according to an operation of the operation unit 101, a PLC modulation unit 103 that superimposes a communication signal from the CPU 102 on a power line L, and a power line. A PLC demodulator 104 that demodulates the communication signal superimposed on L, and a CPU 106 that controls the load 105 in accordance with the communication signal demodulated by the PLC demodulator 104 are provided.

In the conventional communication system 100, the PLC modulation unit 103 and the PLC demodulation unit 104 are connected in parallel to each other. For this reason, the PLC modulation unit 103 superimposes a communication signal on the power line L on the battery 107 side indicated by a bold line in the figure, so that not only the power line L between the PLC modulation unit 103 and the PLC demodulation unit 104 but also other loads A communication signal is also superimposed on the power supply line L connected to 108. Since the power supply line L is provided with an extremely low impedance, if the other load 108 connected to the power supply line L is a capacitive load, the communication signal may be attenuated.

Therefore, when performing PLC communication, it can be considered that the other load 108 is disconnected from the power supply line L, but there is a problem that the timing of communication is limited.

Therefore, an object of the present invention is to provide a communication system that suppresses attenuation of a communication signal superimposed on a power supply line.

A first aspect made to solve the above-described problem includes a transmission unit, a reception unit that receives a communication signal from the transmission unit, a power supply line connected between one electrode of the battery and the load. A modulation unit that superimposes the communication signal from the transmission unit on the power supply line; and a demodulation unit that demodulates the communication signal superimposed on the power supply line and supplies the demodulated signal to the reception unit. The demodulating means is provided on the load side on the power supply line on the battery side on the power supply line, and the modulation means superimposes the communication signal on the load side with respect to the modulation means on the power supply line. It is the communication system characterized by this.

A second mode is the communication system according to the first mode, wherein the modulation unit is configured by a semiconductor transistor in which a communication signal from the transmission unit is input to a control terminal.

The third aspect is further provided with a switching semiconductor transistor that is provided between the battery and another battery and turns on and off the connection between the battery and the other battery, and as a semiconductor transistor constituting the modulation unit, The communication system according to the second aspect, wherein the switching semiconductor transistor is used.

A fourth aspect is the communication system according to the second or third aspect, wherein a pulsed communication signal that gradually rises and gradually falls is input to the control terminal of the semiconductor transistor. is there.

In a fifth aspect, the demodulating means compares the differentiated voltage and a reference voltage with a high-pass filter that differentiates the power supply on the power supply line on which the communication signal is superimposed, and demodulates the comparison result. The communication system according to any one of the first to fourth aspects, further comprising comparison means for outputting the communication signal.

The sixth aspect further includes a communication line for transmitting a communication signal from the transmission means to the reception means, the reception means including the communication signal from the communication line and the power source demodulated by the demodulation means. The communication system according to any one of the first to fifth aspects is provided so that both of the communication signals from the line can be received.

As described above, according to the first aspect, since the communication signal is superimposed on the load side with respect to the modulation means of the power supply line, it is possible to separate another capacitive load from the power supply line on which the communication signal is superimposed. And attenuation of the communication signal superimposed on the power supply line can be suppressed.

According to the second aspect, the modulation means can be provided with a simple configuration.

According to the third aspect, by using the switching semiconductor transistor for turning on and off the connection between the two batteries as the semiconductor transistor of the modulation means, it is not necessary to provide these transistors separately, and the cost can be reduced.

According to the fourth aspect, since the pulsed communication signal that gradually rises and gradually falls is input to the control terminal of the semiconductor transistor, conduction noise can be reduced.

According to the fifth aspect, since the differentiated voltage and the reference voltage are compared, it is possible to accurately demodulate the communication signal without being affected by the power supply voltage and noise.

According to the sixth aspect, a backup can be provided without increasing the number of parts by using the power supply line as a backup of the communication line.

It is a circuit diagram which shows an example of the communication system of this invention. It is a circuit diagram which shows the detail of the modulation | alteration part and demodulation part which comprise the communication system shown in FIG. 1 in 1st Embodiment. It is a circuit diagram which shows the detail of the modulation | alteration part and demodulation part which comprise the communication system which shows FIG. 1 in 2nd Embodiment. It is a time chart of the source output of FET shown in FIG. 3, the output of a differentiation circuit, and the output of a comparator. It is a graph which shows the frequency characteristic of the demodulation part shown in FIG. It is a circuit diagram which shows an example of the communication system in 3rd Embodiment. It is a circuit diagram which shows an example of the communication system in the modification of 3rd Embodiment. It is a time chart of the gate input and source output of FET in 4th Embodiment. It is a graph which shows the frequency characteristic of the conduction noise when the communication signal of tr = tf = 32 microseconds is input into the gate of FET. It is a circuit diagram which shows an example of the communication system in 5th Embodiment. It is a circuit diagram which shows an example of the conventional communication system.

(First embodiment)
The communication system of the present invention in the first embodiment will be described below with reference to FIGS. A communication system 1 shown in the figure is mounted on a vehicle. As shown in the figure, the communication system 1 receives a master control device 2 as a master control means and a transmission means, and a communication signal from the master control device 2, and

loads

31 and 32 according to the received communication signal. Slave control means for controlling, slave control device 4 as receiving means, power supply lines L1 to L3 connected between the positive electrode side of battery B and

loads

31, 32, and

drive devices

51, 52 for driving loads 31, 32 A modulation unit 6 that superimposes the communication signal from the master control device 2 on the power supply lines L2 and L3, and a demodulation unit 7 that demodulates the communication signal superimposed on the power supply line L2 and supplies it to the slave control device 4. I have.

The master control device 2 and the slave control device 4 are constituted by a microcomputer composed of a well-known CPU, ROM, and RAM. The power supply line L <b> 1 is a line connecting the positive electrode side of the battery B and the modulation unit 6. The power supply line L <b> 2 is a line that connects between the modulation unit 6 and the demodulation unit 7. The power supply line L <b> 3 is a line that has one end connected to the demodulator 7 and the other end branched into a plurality of branches and connected to a plurality of

driving devices

51 and 52. The

drive devices

51 and 52 are controlled by the slave control device 4, convert the power supply voltage supplied from the power supply line L 3 into a drive voltage, and supply the drive voltages to the

loads

31 and 32.

The modulation unit 6 is provided on the battery B side on the power supply lines L1 to L3, and the demodulation unit 7 is provided on the

load

31 and 32 side on the power supply lines L1 to L3, and they are connected in series.

As shown in FIG. 2, the modulation unit 6 is composed of an n-channel FET Q1 (semiconductor transistor). The source of the FET Q1 is connected to the power supply line L1, and the drain is connected to the power supply line L2. That is, it is provided so that the forward direction of the parasitic diode D1 of the FET Q1 faces the

loads

31 and 32. Further, a pulsed communication signal of about 10 kHz, for example, from the master control device 2 is inputted to the gate (control terminal) of the FET Q1.

According to the above configuration, when the communication signal is at the H level, the FET Q1 is turned on, so that the power supply voltage Vb which is the potential on the positive side of the battery B is output to the power supply line L2. On the other hand, when the communication signal is at the L level, the FET Q1 is turned off, so that a voltage that is lowered from the power supply voltage Vb by the voltage drop Vf due to the parasitic diode D1 of the FET Q1 is output to the power supply line L2. Thereby, the modulation unit 6 superimposes the communication signal on the power supply voltage Vb supplied by the power lines L2 and L3 on the

loads

31 and 32 side. No communication signal is superimposed on the power line L1 on the battery B side.

As shown in FIG. 2, the demodulator 7 includes a low-pass filter F1, voltage dividing resistors R11 and R12, and a comparator CP1. The low-pass filter F1 includes a resistor R13 and a capacitor C1, and removes a communication signal having a frequency higher than the cutoff frequency from the voltage supplied from the power supply line L2, and outputs only the power supply voltage Vb. The voltage dividing resistors R11 and R12 divide the power supply voltage Vb output from the low-pass filter F1 and input it to the comparator CP1 as a reference voltage.

The voltage dividing resistors R11 and R12 are set so that the reference voltage supplied to the comparator CP1 is lower than the power supply voltage Vb and higher than the voltage obtained by subtracting the voltage drop Vf from the power supply voltage Vb. The comparator CP1 further receives the power supply voltage Vb on which the communication signal supplied from the power supply line L2 is superimposed. The comparator CP1 compares the power supply voltage Vb with the reference voltage, and outputs a comparison result as a communication signal. Supply.

According to the communication system 1 having the above configuration, when the master control device 2 transmits a communication signal, the modulation unit 6 superimposes the communication signal on the power lines L2 and L3 on the

loads

31 and 32 side. The demodulator 7 demodulates the communication signal superimposed on the power supply lines L 2 and L 3 and outputs the demodulated signal to the slave control device 4. The slave control device 4 drives the

loads

31 and 32 by driving the

drive devices

51 and 52 in accordance with the communication signal demodulated by the demodulator 7.

According to the above-described embodiment, the modulation unit 6 is provided on the battery B side on the power supply lines L1 to L3, and the demodulation unit 7 is provided on the

loads

31 and 32 side on the power supply lines L1 to L3. In the lines L1 to L3, communication signals are superimposed on the power supply lines L2 and L3 closer to the

loads

31 and 32 than the modulation unit 6. Therefore, the communication signal is not superimposed on the power line L1 on the battery B side as in the prior art, and the power lines L2, L3 on which the communication signal is superimposed with the other capacitive load 10 connected to the power line L1. And the attenuation of communication signals superimposed on the power supply lines L2 and L3 can be suppressed.

Further, according to the above-described embodiment, the modulation unit 6 is provided on the power supply lines L1 to L3, and is configured by the FET Q1 in which the communication signal from the master control device 2 is input to the gate. Thereby, the modulation | alteration part 6 can be provided with a simple structure.

Note that, according to the above-described embodiment, the FET Q1 is used as the semiconductor transistor, but the present invention is not limited to this. For example, a bipolar transistor may be used instead of the FET Q1. Since the bipolar transistor does not have a parasitic diode D1, if a diode is connected between the emitter and the collector, it functions in the same way as the FET Q1.

(Second Embodiment)
Next, the communication system of the present invention in the second embodiment will be described below with reference to FIGS. In FIG. 3, parts equivalent to those already described in the first embodiment with reference to FIG. 2 are denoted by the same reference numerals and detailed description thereof is omitted. The difference between the first embodiment and the second embodiment is the configuration of the demodulator 7. Since the parts other than the demodulator 7 are the same as those of the first embodiment described above, a detailed description thereof will be omitted.

The demodulator 7 includes a high-pass filter F2, a low-pass filter F1, voltage dividing resistors R14 and R15, and a comparator CP2 as a comparison unit. The high-pass filter F2 includes a primary filter F21 and a secondary filter F22 that differentiate a voltage on the power supply line L2 on which a communication signal is superimposed, an amplifier circuit 71 provided between the primary filter F21 and the secondary filter F22, It is composed of

The primary filter F21 includes a resistor R16 and a capacitor C2, and removes a lower frequency component than the cutoff frequency (for example, 5 kHz) from the voltage on the power supply line L2. The amplifier circuit 71 has an OP amplifier OP1, amplifies the output from the primary filter F21, and inputs the amplified output to the secondary filter F22. The secondary filter F22 includes a resistor R17 and a capacitor C3, removes a lower frequency component than the cutoff frequency (for example, 10 kHz) from the output of the amplifier circuit 71, and supplies it to the comparator CP2.

That is, from the high-pass filter F2, as shown in FIG. 4, a power supply voltage on which the communication signal is superimposed, that is, an edge detection signal obtained by differentiating the modulated communication signal is output and input to the comparator CP2. The edge detection signal outputs a triangular wave in the negative direction when the modulated communication signal falls from the power supply voltage Vb by the voltage drop Vf, and in the positive direction when it rises to the power supply voltage Vb from the state dropped by the voltage drop Vf. A triangular wave is output.

Since the low-pass filter F1 is the same as that of the first embodiment, detailed description thereof is omitted here. The voltage dividing resistors R14 and R15 divide the power supply voltage Vb output from the low-pass filter F1 and input it to the comparator CP2 as a reference voltage.

The voltage dividing resistors R14 and R15 are set such that the reference voltage supplied to the comparator CP2 is lower than the maximum value of the edge detection signal as shown in FIG. The comparator CP2 compares the edge detection signal with the reference voltage, outputs the comparison result as a demodulated communication signal, and supplies it to the slave control device 4. As a result, the demodulated communication signal has a waveform in which one pulse is output every time the communication signal before modulation rises, and nothing is output at the fall.

In the first embodiment, the modulated communication signal itself is compared with the reference voltage. It is predicted that the power supply voltage of the actual vehicle will not be stable due to influences such as fluctuations in the voltage level during load driving and noise superposition on the power supply line L2. Therefore, in the method of the first embodiment, it is difficult to demodulate the communication signal.

According to the second embodiment described above, the modulated communication signal is differentiated and an edge detection signal is output, and the edge detection signal is compared with the reference voltage. The communication signal superimposed on the power supply line L2 can be demodulated.

Moreover, an OP amplifier OP1 is used for the high-pass filter F2. Since the OP amplifier OP1 cannot pass through a wide area, a low-pass filter is naturally formed. For this reason, as shown in FIG. 5, not only the low frequency noise by the primary filter F21 and the secondary filter F22 but also the high frequency noise can be cut. Thereby, the communication signal superimposed on the power supply line L2 can be demodulated more accurately. In addition, just by adding the high-pass filter F2, it is possible to obtain the same effect as adding the low-pass filter.

In the second embodiment, the number of OP amplifiers used is increased from one to two compared to the first embodiment, but the upper limit of the cost is minimized by using a device such as two OP amplifiers. Can be suppressed.

(Third embodiment)
Next, the communication system of the present invention in the third embodiment will be described below with reference to FIG. In FIG. 6, the demodulator 7, the slave control device 4, and the

drive devices

51 and 52 are omitted. As shown in FIG. 6, the communication system of the third embodiment is premised on being provided in a vehicle on which two batteries B1 and B2 are mounted. The batteries B1 and B2 are batteries having different rated voltages.

The battery B1 is composed of, for example, a lead battery for starting the engine. The battery B2 as another battery is composed of lithium ions for voltage stabilization and is connected in parallel to the battery B1. A starter motor M, an alternator ALT, general loads 33 and 34, and a traveling system load 35 are connected in parallel to the batteries B1 and B2.

In such a vehicle equipped with two batteries B1 and B2, a switching unit 11 for turning on / off the connection between the batteries B1 and B2 is generally provided. The switching unit 11 includes two n-channel FETs Q11 and Q12 provided between the batteries B1 and B2,

gate drivers

11a and 11b for driving the FETs Q11 and Q12, and a switching control circuit 11c for controlling the

gate drivers

11a and 11b. And.

FETQ11 and Q12 are connected in series between batteries B1 and B2. The FETs Q11 and Q12 are connected in series so that the parasitic diodes D11 and D12 are opposite to each other. As a result, when the power supply voltage of the battery B1 is higher than that of the battery B2, or when the power supply voltage of the battery B2 is higher than that of the battery B1, the parasitic diode D11 is turned off when the two FETs Q11 and Q12 are turned off. And the battery B1 and B2 can be completely disconnected without any current flowing through D12.

The starter motor M, the alternator ALT, and the general load 33 are connected to the battery B1 side of the FETs Q11 and Q12. Therefore, when the FETs Q11 and Q12 are turned off, the connection with the battery B2 is cut off. On the other hand, since the general load 34 is connected between the FETs Q11 and Q12, when the FETs Q11 and Q12 are turned off, the connection between the batteries B1 and B2 is cut off. Further, since the traveling system load 35 is connected to the battery B2 side with respect to the FETs Q11 and Q12, when the FETs Q11 and Q12 are turned off, the connection with the battery B1 is cut off.

The switching control circuit 11c is composed of a CPU, for example, and controls the connection between the batteries B1 and B2 by controlling on / off of the FETs Q11 and Q12 according to a command from the host unit.

In the third embodiment, the switching unit 11 is used as a modulation unit, and the FET Q12 is used as an FET constituting the modulation unit. That is, the switching control circuit 11c is connected to the master control device 2 described in the first embodiment, and receives a communication signal from the master control device 2. The switching control circuit 11c always turns on the FET Q11 when performing PLC communication, and turns on / off the FET Q12 according to the received communication signal.

Thus, as in the first embodiment, when the FET Q12 is on, the power supply voltage Vb that is the potential on the positive side of the battery B1 is output to the power supply line L2. On the other hand, when the FET Q12 is OFF, a voltage that is lowered from the power supply voltage Vb by the voltage drop Vf due to the parasitic diode D12 of the FET Q12 is output to the power supply line L2. That is, the switching unit 11 superimposes a communication signal on the power supply voltage Vb supplied by the power supply line L2 on the traveling system load 35 side as indicated by a dotted line. No communication signal is superimposed on the power supply line L1 on the battery B1 side.

According to the third embodiment described above, the switching FET Q12 that turns on and off the connection between the two batteries B1 and B2 is used as the FET of the modulation unit. Thereby, it is not necessary to provide these FETs separately, and the modulation part can be provided while minimizing additional parts, so that the cost can be reduced. In addition to the switching function, the switching unit 11 adds a communication function to increase added value.

In addition, according to 3rd Embodiment mentioned above, although FETQ11 and Q12 were connected in series so that the parasitic diodes D11 and D12 might become the mutually reverse direction, it is not restricted to this. For example, as shown in FIG. 7, two FETs Q11 and Q12 are connected in series so that the parasitic diodes D11 and D12 are in the same direction. The two FETs Q11 and Q12 are provided to switch between the batteries B1 and B2 that supply power to the general loads 33 and 34 and the traveling system load 35.

In the case shown in FIG. 7, both FETs Q11 and Q12 can be used as FETs constituting the modulation unit. More specifically, the switching control circuit 11c is connected to the master control device 2 described in the first embodiment, and receives a communication signal from the master control device 2. When performing PLC communication, the switching control circuit 11c always turns on the FET Q11 and turns the FET Q12 on and off according to the received communication signal. Since this is the same as that described with reference to FIG. 6, a detailed description thereof will be omitted.

Also, the switching control circuit 11c can always turn on the FET Q12 and turn the FET Q11 on and off according to the received communication signal. Thus, when the FET Q11 is on, the power supply line L2 between the FET Q11 and the general load 34 and the power supply line L2 between the FET Q12 and the traveling system load 35 are supplied with the power supply voltage Vb that is the potential on the positive side of the battery B1. Is output. On the other hand, when the FET Q11 is OFF, the power supply line L2 between the FET Q11 and the general load 34 and the power supply line L2 between the FET Q12 and the traveling system load 35 are supplied with a voltage drop Vf due to the parasitic diode D11 of the FET Q11. A voltage that has been reduced by a certain amount is output. That is, the switching unit 11 can superimpose a communication signal on the power supply voltage Vb supplied to both the general load 34 and the traveling system load 35, as indicated by a dashed line.

(Fourth embodiment)
Next, the communication system of the present invention in the fourth embodiment will be described below with reference to FIGS. Since the configuration of the communication system of the fourth embodiment is the same as that of the communication system of the first embodiment shown in FIG. 1, detailed description thereof is omitted here. A significant difference between the fourth embodiment and the first embodiment is the waveform of the communication signal supplied to the gate of the FET Q1.

The communication system 1 in the first embodiment described above superimposes communication signals by changing the level of the power supply voltage Vb. For this reason, generation | occurrence | production of the conduction noise was confirmed.

The main cause of conduction noise is a steep voltage change when FETQ1 is switched on and off. For this reason, in this embodiment, as shown in FIG. 8, a pulsed communication signal that gradually rises and gradually falls is input to the gate of the FET Q1. When such a communication signal is input, as shown in the figure, the modulated communication signal, the fluctuation from the power supply voltage Vb to (power supply voltage Vb−voltage drop Vf), (power supply voltage Vb−voltage drop Vf) The power supply voltage Vb is also gradually changed, and the conduction noise can be reduced.

Next, the inventors measured the noise level while gradually increasing the rise time tr and the fall time tf of the communication signal input to the gate of the FET Q1. As a result, as shown in FIG. 9, it was found that when tr = tf = 32 μs or more, the power line conduction emission standard (CISPR25 Class5) was satisfied. In FIG. 9, the frequency characteristic of the noise level peak value when the communication signal is tr = tf = 32 μs is indicated by a dotted line, and the average value is indicated by a solid line. From this figure, it was found that when tr = tf = 32 μs, both the peak value and the average value satisfy the standard.

(Fifth embodiment)
Next, the communication system of the present invention in the fifth embodiment will be described below with reference to FIG. In FIG. 10, parts equivalent to those already described in the first embodiment with reference to FIG. 1 are given the same reference numerals, and detailed descriptions thereof are omitted.

As shown in the figure, the communication system 1 detects the state of the battery B and receives a detection signal (communication signal) from the battery sensor 9 as a transmission unit that outputs the detection signal. Smart power supply boxes 10a to 10d as receiving means for controlling the loads 36a to 36d according to the received detection signals, power supply lines L1 to L3 connected between the positive side of the battery B and the loads 36a to 36d, and battery sensors 9, a modulation unit 6 that superimposes the detection signal from the power supply lines L2 and L3, a demodulation unit 7a to 7d that demodulates the detection signal superimposed on the power supply line L2 and supplies the detection signal to the smart power supplies BOX 10a to 10d, and a battery sensor 9 And a communication line Lc for transmitting the detection signals from the smart power supplies BOX 10a to 10d.

The battery sensor 9 detects the remaining capacity of the battery B and the voltage at both ends, and transmits the detection signal to the smart power supply boxes 10a to 10d via the communication line Lc and the power supply line L2. A communication method via the communication line Lc is performed by a well-known LIN or CAN. Communication via the power line L2 is performed in the same manner as in the first embodiment.

The smart power supplies BOX 10a to 10d are constituted by a microcomputer composed of a well-known CPU, ROM, and RAM. The smart power supplies BOX 10a to 10d are provided so as to receive both the detection signal via the communication line Lc and the detection signal via the power line L2.

The power supply line L1 is a line that connects the positive electrode side of the battery B and the modulation unit 6 as in the first embodiment. The power supply line L2 is a line that connects between the modulation unit 6 and the demodulation units 7a to 7d. The power supply line L3 is a line that connects between the demodulation units 7a to 7d and the loads 36a to 36d.

Since the modulation unit 6 and the demodulation units 7a to 7d are the same as the modulation unit 6 and the demodulation unit 7 of the first embodiment, detailed description thereof is omitted. Each of the smart power supplies BOX 10a to 10d autonomously controls each of the loads 36a to 36d in accordance with a detection signal from the battery sensor 9 (for example, when the remaining capacity of the battery B is small, the audio system is a part not related to running). Shut off the power supply to the load).

As described above, in the fifth embodiment, the detection signal is transmitted from the battery sensor 9 to the smart power supply boxes 10a to 10d through the communication line Lc and the power supply line L2. The smart power supplies BOX 10a to 10d normally receive a detection signal via the communication line Lc. Smart power supplies BOX 10a to 10d determine that communication is interrupted when the detection signals cannot be received from communication line Lc, and receive detection signals via power supply line L2 demodulated by demodulation sections 7a to 7d.

According to the embodiment described above, by using the power supply line L2 as a backup of the communication line Lc, a backup can be provided without increasing the number of components, and the detection signal from the battery sensor 9 can be reliably transmitted to the smart power supply box 10a˜ 10d can receive.

In the future, the mainstream of on-board batteries is likely to change from lead to lithium. Lithium requires a higher level of battery management than lead. In addition, it is necessary to ensure the reliability of communication by proceeding with automatic operation, or reliability can be ensured by using the above-described embodiment.

In addition, according to the above-described embodiment, the smart power supplies BOX 10a to 10d autonomously control the loads 36a to 36d. As a result, higher functionality can be achieved compared to a case where a control unit such as one ECU controls the plurality of loads 36a to 36d collectively.

In addition, the communication system is separately provided in the PLC performed in the power supply lines L1 to L3 separately from the LIN and CAN performed in the communication line Lc, and there is an advantage that the worry of simultaneous multiple failures can be reduced.

Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Communication system 2 Master control apparatus (transmission means)
4 Slave controller (reception means)
6 Modulator (Modulation means)
7 Demodulator (demodulator)
9 Battery sensor (transmission means)
10a to 10d Smart power supply BOX (reception means)
11 Switching unit (modulation unit)
31 Load 32 Load 35 Traveling system load (load)
36a to 36d Load B Battery B1 Battery B2 Battery (Other battery)
CP2 comparator (comparison means)
F2 High-pass filter L1 to L3 Power line Lc Communication line Q1 FET (semiconductor transistor)
Q12 FET (semiconductor transistor, switching semiconductor transistor)

Claims

A transmission means; a reception means for receiving a communication signal from the transmission means; a power line connected between one electrode of the battery and the load; and a modulation for superimposing the communication signal from the transmission means on the power line. And a demodulating means for demodulating the communication signal superimposed on the power line and supplying the demodulated signal to the receiving means,
The modulation means is provided on the battery side on the power supply line, the demodulation means is provided on the load side on the power supply line, and the modulation means is provided on the load side of the power supply line rather than the modulation means. A communication system characterized by superimposing.
2. The communication system according to claim 1, wherein the modulation unit includes a semiconductor transistor in which a communication signal from the transmission unit is input to a control terminal.
A switching semiconductor transistor that is provided between the battery and another battery and that turns on and off the connection between the battery and the other battery;
The communication system according to claim 2, wherein the switching semiconductor transistor is used as a semiconductor transistor constituting the modulation means.
The communication system according to claim 2 or 3, wherein a pulsed communication signal that gradually rises and gradually falls is input to a control terminal of the semiconductor transistor.
The demodulating unit compares the differentiated voltage with a reference voltage with a high-pass filter that differentiates the power supply on the power supply line on which the communication signal is superimposed, and outputs the comparison result as the demodulated communication signal. The communication system according to any one of claims 1 to 4, further comprising a comparison unit.
A communication line for transmitting a communication signal from the transmitting means to the receiving means;
The receiving means is provided so as to receive both a communication signal from the communication line and a communication signal from the power line demodulated by the demodulating means. The communication system according to any one of the above.