Communication device, charge communication system, transportation apparatus and fault diagnosis method

A communication device comprises a connector to which a communication line is to be connected for sending and receiving a control signal concerning charge control between a transportation apparatus and a charging apparatus, a modem outputting a modulated signal obtained by modulating information to be sent and demodulating the modulated signal input, and a first internal communication line and a second internal communication line each being connected to the connector and the modem, the first internal communication line and the second internal communication line respectively being for sending the modulated signal and being for receiving the modulated signal, and sends and receives the modulated signal by superposing the modulated signal on the control signal. The modem outputs a beacon signal for communication, and comprises a branch line branched at an intermediate location of the second internal communication line, a wave detector circuit that detects the beacon signal transmitted to the branch line by way of the first internal communication line, the connector and the second internal communication line, and a diagnosis unit that performs a fault diagnosis of its own device based on a signal obtained through detection by the wave detector circuit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the national phase under 35 U. S. C. § 371 of PCT International Application No. PCT/JP2017/020656 which has an International filing date of Jun. 2, 2017 and designated the United States of America.

FIELD

The present invention relates to a communication device, a charge communication system, a transportation apparatus and a fault diagnosis method.

The present application claims the benefit of Japanese Patent Application No. 2016-121113 filed on Jun. 17, 2016, the entire contents of which are hereby incorporated by reference.

BACKGROUND

A plug-in hybrid electric vehicle (PHEV) using an electric motor and an engine in combination as well as an electric vehicle (EV) driven by an electric motor without being provided with an engine have been in widespread use. A vehicle such as a plug-in hybrid electric vehicle, an electric vehicle and so on has a battery to supply power for driving the electric motor while performing the charging of the battery by using an external charging station.

When performing the charging of the battery, the vehicle and the charging station send and receive to and from each other various types of information such as the control information concerning charging, the identifying information of the vehicle, the accounting information and so on. For example, the vehicle and the charging station are provided with CPLT communication devices that send and receive to and from each other control pilot (CPLT) signals indicative of the connection of a charging cable, the completion of the preparation for charging, the charging state and so on through communication lines for the charging cable. The vehicle and the charging station may send and receive simple information by using control pilot signals, but have a limited information amount that may be sent and received. Hence, it has been considered that the vehicle and the charging station are provided with PLC communication devices so that a higher degree of information communication is achieved. The PLC communication device may send and receive more information by sending and receiving control pilot signals on each of which other signals are superposed.

Meanwhile, as the information sent and received to and from the vehicle and the charging station increases, techniques of detecting the fault of the communication line between the vehicle and the charging station and the fault of the communication device have increased in importance.

Japanese Patent Application Laid-Open No. 2009-71989 discloses a charging control apparatus that is capable of detecting a disconnection of the communication line extending between a vehicle and a charging station. Moreover, Japanese Patent Application Laid-Open No. 2013-90544 discloses an electronic control device that is capable of detecting a failure of a switching element to change the voltage level of a pilot signal and a disconnection and a ground failure of the communication lines.

SUMMARY

A communication device according to the present aspect is a communication device that comprises a connector to which a communication line is to be connected for sending and receiving a control signal concerning charge control between a transportation apparatus and a charging station, a modem outputting a modulated signal obtained by modulating information to be sent and demodulating the modulated signal input, and a first internal communication line and a second internal communication line each being connected to the connector and the modem, the first internal communication line and the second internal communication line respectively being for sending the modulated signal and being for receiving the modulated signal, and the modem is capable of outputting a beacon signal for communication to the charging station through the first internal communication line and the communication line and outputting the beacon signal through the first internal communication line and the second internal communication line, and sends and receives the modulated signal by superposing the modulated signal on the control signal. The communication device comprises: a branch line branched from an intermediate location of the second internal communication line; a wave detector circuit that detects the beacon signal transmitted to the branch line by way of the first internal communication line, the connector and the second internal communication line; and a diagnosis unit that performs a fault diagnosis of its own device based on a signal obtained through detection by the wave detector circuit.

Here, supplementary explanation is made on a term described in claims. The term “own device” indicates a communication device. That is, “a fault diagnosis of an own device” indicates the fault diagnosis of at least all or part of the connector, the modem, the first internal communication line, the second internal communication line and the communication line, and various circuits and elements provided along the communication path that are contained in the communication device equivalent to “own device.” The explanation is common to all the claims.

It is noted that the present application may be realized as a communication device having such a characteristic processing unit as well as may be realized as a fault diagnosis method regarding such characteristic processing as steps and as a program causing a computer to execute such steps. Moreover, the present application may be realized as a semiconductor integrated circuit realizing a part or all of the communication device as well as may be realized as another system or a transportation apparatus including the communication device.

DETAILED DESCRIPTION

Problems to be Solved by Disclosure

The related art has a problem in which the fault external to the PLC communication device may be detected such as the disconnection of a communication line through which a control pilot signal is transmitted whereas the fault internal to the PLC communication device cannot be detected.

The present disclosure is to provide a communication device capable of performing a fault diagnosis of the inside of its own device, a charge communication system, a transportation apparatus and a fault diagnosis method.

Effects of Disclosure

According to the present disclosure, it is possible to provide a communication device capable of performing a fault diagnosis of the inside of its own device, a charge communication system, a transportation apparatus and a fault diagnosis method.

Description of Embodiments of Present Application

Embodiments of the present disclosure are first listed. Moreover, at least parts of the embodiments that will be described below may arbitrarily be combined.

(1) A communication device according to this aspect comprises a connector to which a communication line is to be connected for sending and receiving a control signal concerning charge control between a transportation apparatus and a charging station, a modem outputting a modulated signal obtained by modulating information to be sent and demodulating the modulated signal input, and a first internal communication line and a second internal communication line each being connected to the connector and the modem, the first internal communication line and the second internal communication line respectively being for sending the modulated signal and being for receiving the modulated signal. The modem is capable of outputting a beacon signal for communication to the charging station through the first internal communication line and the communication line and outputting the beacon signal through the first internal communication line and the second internal communication line, and sends and receives the modulated signal by superposing the modulated signal on the control signal. The communication device comprises: a branch line branched at an intermediate location of the second internal communication line; a wave detector circuit that detects the beacon signal transmitted to the branch line by way of the first internal communication line, the connector and the second internal communication line; and a diagnosis unit that performs a fault diagnosis of its own device based on a signal obtained through detection by the wave detector circuit.

(2) Such a configuration is preferable that the communication device further comprises an obtainment unit that obtains connection information indicative of a connection or a disconnection of a charging cable of the charging station and the transportation apparatus, and the diagnosis unit performs a fault diagnosis of its own device if the connection information indicates the disconnection of the charging cable.

(3) Such a configuration is preferable that the communication device further comprises a speed information obtainment unit that obtains speed information indicative of a speed of the transportation apparatus mounted with its own device, and the diagnosis unit performs a fault diagnosis of its own device if a speed indicated by the speed information is equal to or larger than a predetermined value.

(4) Such a configuration is preferable that the modem comprises an output unit connected to the first internal communication line and an input unit connected to the second internal communication line, and outputs the beacon signal from the output unit regarding the modem as a sending source and a sending destination, and the diagnosis unit performs a fault diagnosis of each part from the output unit through the first internal communication line, the connector and the second internal communication line to the branch line based on a signal obtained through detection by the wave detector circuit.

(5) A charge communication system according to this aspect comprises: the communication device according to any one of the aspects (1) to (4); and a charging station that sends and receives the control signal and the modulated signal to and from the communication device through the charging cable.

(6) A transportation apparatus according to this aspect comprises the communication device according to any one of the aspects (1) to (4).

(7) A fault diagnosis method according to this aspect is a fault diagnosis method for the communication device comprising a connector to which a communication line is to be connected for sending and receiving a control signal concerning charge control between a transportation apparatus and a charging station, a modem outputting a modulated signal obtained by modulating information to be sent and demodulating the modulated signal input, and a first internal communication line and a second internal communication line each being connected between the connector and the modem, the first internal communication line and the second internal communication line respectively being for sending the modulated signal and being for receiving the modulated signal. The modem is capable of outputting a beacon signal for communication to the charging station through the first internal communication line and the communication line and outputting the beacon signal through the first internal communication line and the second internal communication line, and sends and receives the modulated signal by superposing the modulated signal on the control signal. The fault diagnosis method comprises: branching the beacon signal transmitted by way of the first internal communication line, the connector and the second internal communication line at an intermediate location and detecting the branched beacon signal, and performing a diagnosis of its own device based on a signal obtained through detection.

In the present aspect, the modem outputs a beacon signal for communication. The beacon signal is an analog signal and is transmitted to the branch line by way of the first internal communication line, the connector and the second internal communication line. The wave detector circuit detects the beacon signal having been transmitted so as to be branched to the branch line. In the case where a fault exists in an intermediate location of the communication path for the beacon signal, a signal obtained through detection by the beacon signal varies depending on the location and content of the fault. Furthermore, in the case where abnormality occurs in the modem itself as well, a signal obtained by detection is different from that obtained at a normal time. Accordingly, the communication device may detect the abnormality occurring at the connector and the internal circuit of its own device by analyzing the beacon signal.

Since such a configuration is employed that an analogue beacon signal is transmitted through the first internal communication line, the connector and the second internal communication line, and is then detected, a fault that could not be detected by merely monitoring the abnormality of sending and receiving of the modulated signal by the modem may also be detected. It is also possible to detect a fault at a prior stage where the communication of the modulated signal is disabled.

It is noted that the modem that outputs a modulated signal obtained by modulating the information to be sent and decodes the input modulated signal does not necessarily mean that the modem has a configuration to receive the modulated signal output by itself and demodulate this modulated signal.

According to the present aspect, the communication device detects that the charging cable of the charging station is connected to the transportation apparatus. If the charging cable is connected to the transportation apparatus, the transportation apparatus is highly likely to be being charged, and there is a fear that the sending and receiving of beacon signals and detecting of a beacon signal will be hampered. That is, there is a possibility that the fault diagnosis of the communication device may not accurately be performed. Hence, the communication device performs the fault diagnosis of its own device if the charging cable is not connected to the transportation apparatus. Accordingly, the communication device may perform an accurate fault diagnosis of its own device in a state where the sending and receiving of beacon signals and detecting of a beacon signal are not hampered.

According to the present aspect, the communication device determines whether or not the speed of the transportation apparatus is equal to or larger than a predetermined value. If the speed of the transportation apparatus is equal to or larger than the predetermined value, there is a low possibility that the apparatus is being charged, and there is no fear that the sending and receiving of beacon signals and detecting of a beacon signal will be hampered. That is, the communication device is in a state where the fault diagnosis thereof may accurately be performed. Hence, the communication device performs a fault diagnosis of its own device if the speed of the transportation apparatus is equal to or larger than the predetermined value. Accordingly, the communication device may perform an accurate fault diagnosis of its own device in the state where the sending and receiving of beacon signals and detecting of a beacon signal are not hampered.

Depending on the specifications of the modem, since it has a function of modulating or demodulating, the modem is configured to ignore the signal that has been sent by its own device even if it receives. That is, even if the modem sends a beacon signal to its own device, it cannot detects the signal, so that the control unit cannot perform a diagnosis of the on-vehicle PLC communication device.

However, according to this aspect, the beacon signal may be received and recognized by the wave detector circuit, so that if the result of detection is sent to the control unit, even such a modem may perform a diagnosis of its own device.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Examples of the communication device, the communication system, the transportation apparatus and the fault diagnosis method according to the embodiments of the present disclosure will be described below in detail with reference to the drawings. It is to be understood that the inventions herein disclosed are illustrative in all respects and not restrictive, and all changes that fall within the meanings and the bounds of the claims, or equivalence of such meanings and bounds are intended to be embraced by the claims.

FIG. 1is a block diagram illustrating one example of the configuration of a charge communication system according to Embodiment 1. The charge communication system according to Embodiment 1 includes a vehicle (transportation apparatus)1such as a plug-in hybrid electric vehicle, an electric vehicle or the like, a charging cable3and a charging station2that supplies power to the battery of the vehicle1through the charging cable3.

The charging cable3has one end portion connected to the charging station2and the other end portion provided with a charging gun3a. The charging cable3includes two power supply lines31, an in-cable communication line32, an in-cable ground line33and so on. Each of the power supply lines31is a conducting wire to which voltage of DC (direct current) or AC (alternating current) output from the charging station2is to be applied. The in-cable communication line32is a conducting wire to transmit a control pilot signal for controlling the charging of the battery mounted on the vehicle1. The in-cable ground line33is a conducting wire to be connected to the reference potential of the control pilot signal. The reference potential is the reference potential of the vehicle1, for example, a body grounding. As will be described later, the in-cable communication line32and the in-cable ground line33also function as transmission media for differential signals to be sent and received so as to be superposed on the control pilot signals. The control pilot signal corresponds to a control signal in the aspect (1) while the differential signal corresponds to a modulated signal.

The charging station2is provided with a power supply device7, a CPLT communication device8and a PLC communication device9.

The power supply device7is connected to one end portions of the power supply lines31and supplies DC or AC to the vehicle1through the power supply lines31.

The CPLT communication device8sends and receives control pilot signals to control the charging of the battery mounted on the vehicle1via the PLC communication device9. The control pilot signal is, for example, a rectangular wave signal of 1 kHz. The CPLT communication device8sends and receives information concerning charging, such as the confirmation of the connection between the charging station2and the vehicle1, the chargeability and the state of charge, etc. based on the potential of the rectangular wave signal relative to the reference potential, the presence or absence of the rectangular wave signal and the like. The power supply device7controls power supply by sending and receiving control pilot signals to and from the vehicle1by the CPLT communication device8.

The PLC communication device9is connected to the in-cable communication line32and the in-cable ground line33, and sends and receives information concerning charging to and from the vehicle1by using the in-cable communication line32and the in-cable ground line33. More specifically, the PLC communication device9performs communication of information concerning charging with the vehicle1by sending and receiving control pilot signals on which differential signals of higher frequency than the control pilot signal, for example, differential signals at frequencies in the range of 2 to 30 MHz are superposed.

The vehicle1includes a charging device4to charge the battery, an on-vehicle CPLT communication device5, an on-vehicle PLC communication device (communication device)6, a connection detecting switch10, a vehicle speed sensor11and so on. Inside the vehicle1, the charging device4, the on-vehicle-CPLT communication device5and the on-vehicle PLC communication device6are connected to one another through an in-vehicle network complying with a protocol of, for example, the controller area network (CAN) and may exchange information with one another.

The vehicle1is provided with an inlet1a, and by connecting the charging gun3ato the inlet1a, the vehicle1is connected to the charging station2through the charging cable3. The charging cable3is connected to the vehicle1, so that the power supply lines31are connected to the charging device4while the in-cable communication line32and the in-cable ground line33are connected to the on-vehicle PLC communication device6through an in-vehicle communication line60aand an in-vehicle ground line60b, respectively.

The on-vehicle-CPLT communication device5is connected to the on-vehicle PLC communication device6through an in-vehicle CPLT line60e, and sends and receives control pilot signals to and from the charging station2via the on-vehicle PLC communication device6.

The on-vehicle PLC communication device6is connected to the in-vehicle communication line60aand the in-vehicle ground line60band performs communication of information concerning charging with the charging station2by sending and receiving control pilot signals on which differential signals are superposed.

The charging device4is connected to the other ends of the power supply lines31. The charging device4is a device to charge the battery by the DC or the AC supplied from the charging station2through the power supply lines31. The charging device4controls the charging by sending and receiving control pilot signals by the on-vehicle-CPLT communication device5.

The connection detecting switch10is a switch to detect that the charging gun3aprovided at the end portion of the charging cable3is connected to the inlet1aof the vehicle1. The connection detecting switch10is provided inside the inlet1aof the vehicle1, for example, and may be formed as a switch that is to be pressed by a part of the charging gun3asuch as the end portion or the side surface thereof that is inserted into the inlet1aand may detect the presence or absence of the connection of the charging gun3adepending on the presence or absence of a press. The connection detecting switch10outputs to the on-vehicle PLC communication device6a binary signal indicative of the presence or absence of a connection of the charging gun3aas connection information. The on-vehicle PLC communication device6may determine whether or not the charging cable3is connected to the vehicle1by using the connection information output from the connection detecting switch10.

The vehicle speed sensor11is provided with, for example, a magnetic pickup to generate a signal in proportion to the number of rotations of the axle provided in the vehicle1, a noncontact sensor including a hall element and the like and a counter circuit to count the number of pulses sent from the noncontact sensor, and detects the speed of the vehicle1by measuring the number of pulses. The noncontact sensor is one example of the vehicle speed sensor11, and the vehicle speed sensor11is not limited to such a configuration. For example, the vehicle speed sensor11may be configured so as to obtain the location information of the vehicle1detected by a GPS device and to detect the speed of the vehicle1based on the variation of the location of the vehicle1.

FIG. 2is a circuit block diagram illustrating one example of the configuration of the on-vehicle PLC communication device6. The in-vehicle communication line60aand the in-vehicle ground line60bthat are connected to the on-vehicle PLC communication device6are branched at an intermediate location. The on-vehicle PLC communication device6is provided with a connector66to be connected to the in-vehicle communication line60aand the in-vehicle ground line60bthat serve as main lines, an in-vehicle communication line60cand an in-vehicle ground line60dthat are respectively branched from the in-vehicle communication line60aand the in-vehicle ground line60b, and the in-vehicle CPLT line60e. The connector66is composed of a plug66aand a receptacle66b, for example. Connected to the plug66aare one end portions of the in-vehicle communication lines60aand60c, one end portions of the in-vehicle ground lines60band60d, and one end portion of the in-vehicle CPLT line60e. The other end portions of the in-vehicle communication line60aand the in-vehicle ground line60bare connected to the inlet1a. The receptacle66bis connected to one end portions of a first internal communication line67aand a second internal communication line67c, one end portions of a first internal ground line67band a second internal ground line67d, and one end portion of an internal CPLT line67ethat are disposed inside the on-vehicle PLC communication device6. The plug66ais connected to the receptacle66bof the on-vehicle PLC communication device6, so that the in-vehicle communication lines60aand60c, the in-vehicle ground lines60band60dand the in-vehicle CPLT line60eare respectively connected to the first and the second internal communication lines67aand67c, the first and the second internal ground lines67band67dand the internal CPLT line67ethat are disposed inside the device.

The first internal communication line67aand the first internal ground line67bare each connected to a signal output terminal (output unit)62aof a modem62via a first common mode choke coil L1, a first coupling capacitor C1, a first coupling transformer T1, a DC bias cut capacitor C0, a sending protection circuit63aand a sending pass circuit63b. The first common mode choke coil L1is an element to remove common mode noise put on a differential signal. The first coupling capacitor C1and the first coupling transformer T1each are a circuit to superpose the differential signal output from the modem62on a control pilot signal. The DC bias cut capacitor C0is a capacitor to cut out a direct-current component. The sending protection circuit63ais a circuit to protect the circuit on the sending side of the modem62. The sending pass circuit63bis a filter to pass through only the signal component to be sent, for example, a band-pass filter.

The second internal communication line67cand the second internal ground line67dare each connected to a signal input terminal (input unit)62bof the modem62via a second common mode choke coil L2, a second coupling capacitor C2, a second coupling transformer T2, a receiving protection circuit63cand a receiving filter circuit63d. The second common mode choke coil L2is an element to remove common mode noise put on the differential signal. The second coupling capacitor C2and the second coupling transformer T2each are a circuit to separate a differential signal superposed on a control pilot signal that is sent from the charging station2from the control pilot signal and to output the differential signal to the modem62side. The receiving protection circuit63cis a circuit to protect the circuit on the receiving side of the modem62. The receiving filter circuit63dis a filter to pass through only the signal component to be received, for example, a band-pass filter.

The modem62operates according to the control by the control unit61. The control unit61provides the modem62with the digital data of the information to be sent to the charging station2and instructs the modem62to send the information. The modem62modulates the digital data into a differential signal and outputs the modulated differential signal from the signal output terminal62ato the first internal communication line67aand the in-vehicle communication line60a. The differential signal output from the signal output terminal62aof the modem62is superposed on a control pilot signal by the first coupling transformer T1and the first coupling capacitor C1, and the resultant signal is transmitted through the first internal communication line67a, the in-vehicle communication line60aand the in-cable communication line32and sent to the charging station2.

In the case where a differential signal sent from the charging station2is input to the signal input terminal62bof the modem62, the modem62demodulates the differential signal input to the signal input terminal62bto digital data and provides the digital data obtained through the demodulation to the control unit61.

Furthermore, depending on the specifications of the modem62, since it performs functions such as modulation and demodulation, the modem62is configured to ignore at the signal input terminal62bthe beacon signal sent from the signal output terminal62aby the modem62itself. That is, even if the modem62sends a beacon signal to its own device, it cannot detect the beacon signal input to the signal input terminal62b, so that the control unit61cannot diagnose the fault of the on-vehicle PLC communication device6.

Moreover, the on-vehicle PLC communication device6has a function of performing a diagnosis of a fault of its own device. The modem62voluntarily outputs a beacon signal for communication from the signal output terminal62ain order to perform communication with the charging station2. The beacon signal is an analog signal having a predetermined signal pattern. The beacon signal is a burst signal sent for several hundred microseconds every several dozen of milliseconds. The burst signal is a signal intermittently sent over the period of sending. That is, a single mass of the burst signal according to Embodiment 1 is composed of multiple signals intermittently sent at intervals of several microseconds. The beacon signal for communication with the charging station2that is output from the modem62is transmitted to the charging station2through the first internal communication line67a, the in-vehicle communication line60aand the in-cable communication line32. Furthermore, the beacon signal for communication to be used for fault diagnosis of its own device that is output from the modem62is transmitted through the first internal communication line67aand the second internal communication line67c. More specifically, the beacon signal is transmitted through the sending pass circuit63b, the sending protection circuit63a, the DC bias cut capacitor C0, the first coupling transformer T1, the first coupling capacitor C1, the first common mode choke coil L1, the connector66, the in-vehicle communication lines60aand60c, the connector66, the second common mode choke coil L2, the second coupling capacitor C2, the second coupling transformer T2, the receiving protection circuit63c, the receiving filter circuit63dand is then input to the signal input terminal62bof the modem62and a wave detector circuit65.

The on-vehicle PLC communication device6is provided with branch lines67fbranched at intermediate locations on the second internal communication line67cand on the second internal ground line67d, and the wave detector circuit65that detects a beacon signal transmitted via the first internal communication line67a, the connector66and the second internal communication line67cto each of the branch lines67f. More specifically, the branch lines67fis branched between the receiving filter circuit63dand the modem62, and the wave detector circuit65detects a beacon signal transmitted to the branch line67fvia the first internal communication line67a, the connector66, the in-vehicle communication lines60aand60cand the second internal communication line67c, and outputs a fault detection signal obtained through detection to the control unit61. Hereafter, the signal obtained by the wave detector circuit65detecting the beacon signal is referred to as a fault detection signal. The wave detector circuit65obtains a rectangular-wave fault detection signal by detecting the beacon signal. The fault detection signal is a signal with a part corresponding to a burst section representing the high level and a part corresponding to no burst section representing the low level. The detection method by the wave detector circuit65is not limited to a particular method.

The concrete configuration of the wave detector circuit65will be described below.

The wave detector circuit65is provided with, for example, an amplifier bias circuit, a hold circuit and a comparator. The amplifier bias circuit is a circuit to amplify the signal that is sent to the wave detector circuit65from the modem62through a predetermined circuit as well as to apply constant bias voltage thereto, and outputs the amplified signal to the hold circuit.

The hold circuit is a circuit to hold the peak voltage of the signal amplified by the amplifier bias circuit for a constant period of time. As will be described later, the beacon signal according to Embodiment 1 includes a burst signal sent at predetermined time intervals. A single mass of the burst signal is an aggregate of multiple signals intermittently sent at intervals of several microseconds. Accordingly, if the burst signal input to the wave detector circuit65is merely amplified as it is, the width between the signals constituting the burst signal is too narrow to detect the width of the entire burst signal, the voltage, the sending interval between the burst signal and another burst signal and so on. The hold circuit performs envelope detection of the burst signal by holding the multiple signals constituting the burst signal. More specifically, the hold circuit holds the multiple signals constituting the burst signal so that they are converted into a detection signal corresponding to an envelope of the entire burst signal and outputs the converted detection signal to the comparator.

The comparator converts the detection signal into a rectangular-wave fault detection signal by comparing the detection signal and a predetermined threshold voltage, and outputs the fault detection signal to the control unit61.

The wave detector circuit65thus configured outputs a fault detection signal of high level voltage during which a burst signal is input to the wave detector circuit65and outputs a fault detection signal of low level voltage during which no burst signal is input.

The control unit61obtains the fault detection signal output from the wave detector circuit65, performs a fault diagnosis of the on-vehicle PLC communication device6based on the obtained fault detection signal, and stores the result of the diagnosis. The control unit61functions as a diagnosis unit in the aspect (1). The detail of the configuration and the content of the processing performed by the control unit61will be described later.

Meanwhile, the internal CPLT line67ehas one end connected to an appropriate location of the first internal communication line67a, for example, between the first common mode choke coil L1and the first coupling capacitor C1and the other end connected to the receptacle66bvia a low-pass filter64. The control pilot signal sent from the charging station2is transmitted through the in-vehicle communication line60aand input to the on-vehicle PLC communication device6. The control pilot signal input to the on-vehicle PLC communication device6is transmitted through the internal CPLT line67eand output to the outside of the on-vehicle PLC communication device6via the low-pass filter64. The low-pass filter64is a filter to remove the differential signal superposed on the control pilot signal. The control pilot signal output from the on-vehicle PLC communication device6is sent to the on-vehicle-CPLT communication device5through the in-vehicle CPLT line60e. Similarly, the control pilot signal sent from the on-vehicle-CPLT communication device5is transmitted by way of the in-vehicle CPLT line60e, the low-pass filter64inside the on-vehicle PLC communication device6and the internal CPLT line67eand sent through the in-vehicle communication line60aand the in-cable communication line32to the charging station2.

Moreover, the on-vehicle PLC communication device6is provided with an in-vehicle communication unit68to perform communication with the charging device4, the on-vehicle-CPLT communication device5and so on via the in-vehicle network. The in-vehicle communication unit68sends information to another device by outputting a signal generated based on the information to be sent provided from the control unit61to the bus or the like of the in-vehicle network. The in-vehicle communication unit68samples the signal output from another device by monitoring the voltage of the bus or the like of the in-vehicle network and provides the control unit61with the information obtained from the sampled signal.

Furthermore, the connection information indicative of the result of the connection detection output by the connection detecting switch10and the vehicle speed information output from the vehicle speed sensor11are input to the control unit61. According to the present embodiment, the control unit61controls the operation of the modem62based on the input connection information and vehicle speed information.

FIG. 3is a block diagram illustrating an internal configuration of the control unit61. The control unit61is a microprocessor having a central processing unit (CPU)61aand so on. The CPU61ais connected via a bus to a storage unit61b, a first input/output unit61c, a second input/output unit61d, a third input/output unit61e, a fourth input/output unit61fand a fifth input/output unit61gand so on. The modem62, the in-vehicle communication unit68, the wave detector circuit65, the connection detecting switch10and the vehicle speed sensor11are respectively connected to the first input/output unit61c, the second input/output unit61d, the third input/output unit61e, the fourth input/output unit61fand the fifth input/output unit61g.

The storage unit61bincludes, for example, a nonvolatile memory and a volatile memory. The nonvolatile memory is, for example, a ROM such as an EEPROM. The nonvolatile memory stores a control program required for the initial operation of the computer and a fault diagnosis program61ifor executing a fault diagnosis and the like of its own device by controlling the operation of the on-vehicle PLC communication device6. The volatile memory is, for example, a dynamic RAM (DRAM), a static RAM (SRAM) or the like and temporarily stores the control program read from the nonvolatile memory when arithmetic processing is executed by the CPU61a, the fault diagnosis program61ior various data generated by the arithmetic processing executed by the CPU61a. Furthermore, the storage unit61bstores a fault diagnosis table61hto perform a fault diagnosis of its own device. The fault diagnosis table61hstores the waveforms and cycles of the fault detection signals obtained through detection by the wave detector circuit65, the locations of the faults and the contents of the faults in association with one another.

The digital data sent by the charging device4via the in-vehicle network is received by the in-vehicle communication unit68and is given to the control unit61. The CPU61aof the control unit61obtains the digital data output from the in-vehicle communication unit68via the second input/output unit61dand outputs the obtained digital data to the modem62via the first input/output unit61c. The modem62modulates the digital data into a differential signal and outputs the same to the first internal communication line67aand the in-vehicle communication line60a. Moreover, the modem62demodulates a differential signal sent from the charging station2and outputs digital data obtained through demodulation to the control unit61. The CPU61aperforms sending to the charging device4by obtaining the digital data output from the modem62via the first input/output unit61cand outputting the obtained digital data to the in-vehicle communication unit68via the second input/output unit61d. Thus, the on-vehicle PLC communication device6performs information communication with the charging station2.

Furthermore, the CPU61aexecutes the fault diagnosis program61istored in the storage unit61bto thereby control the operation of each of the components and perform a fault diagnosis of the on-vehicle PLC communication device6being its own device. More specifically, the CPU61ainstructs the modem62to output a beacon signal via the first input/output unit61cand obtains a fault detection signal output by the wave detection circuit65via the third input/output unit61e. The CPU61athen performs a diagnosis of its own device based on the obtained fault detection signal.

Furthermore, the CPU61aobtains the connection information from the connection detecting switch10via the fourth input/output unit61fwhile obtaining the vehicle speed information from the vehicle speed sensor11via the fifth input/output unit61g. The CPU61aperforms communication processing with the charging station2and fault diagnosis processing for the inside of the on-vehicle PLC communication device6based on the obtained connection information and vehicle speed information.

FIG. 4is a state transition diagram for depicting communication processing and fault diagnosis processing to be performed by the on-vehicle PLC communication device6. The on-vehicle PLC communication device6according to the present embodiment performs communication processing with the charging station2and fault diagnosis processing for the inside of the on-vehicle PLC communication device6while shifting among four states, a standby state, a running state, a fault diagnosis state and a communication state.

In the case where the speed of the vehicle1is smaller than a predetermined value and the charging gun3is not connected to the inlet1aof the vehicle1, the on-vehicle PLC communication device6enters the standby state. The standby state is a state where the connection with the charging station2is held on standby.

If the speed of the vehicle1changes to a predetermined value or larger in the standby state, the on-vehicle PLC communication device6shifts to the running state. In the running state, the on-vehicle PLC communication device6is supplied with power from a battery for traveling, a battery for auxiliary machinery and the like, and enters a state where a fault diagnosis processing is possible.

If the charging gun3ais connected to the inlet1aof the vehicle1in the standby state, the on-vehicle PLC communication device6shifts to the communication state. The communication state is a state where the vehicle1and the charging station2are connected to each other via the charging cable3, so that communication with charging station2is being performed or is possible. If the connection of the charging gun3is released in the communication state, the on-vehicle PLC communication device6shifts to the standby-state.

After shifting from the standby state to the running state, the on-vehicle PLC communication device6determines in the running state whether or not the fault diagnosis processing has been executed. If the fault diagnosis processing has not yet been executed, the on-vehicle PLC communication device6shifts to the fault diagnosis state. The fault diagnosis state is a state where the on-vehicle PLC communication device6performs a fault diagnosis by outputting a beacon signal from the modem62. If the fault diagnosis processing is ended, the on-vehicle PLC communication device6shifts to the running state. Here, the on-vehicle PLC communication device6stores whether or not the fault diagnosis processing has been performed as information such as a flag or the like and does not perform the processing again after the fault diagnosis processing is performed once. It is noted that if the running state shifts to the standby state, the stored information of the flag is reset. For this reason, if the standby state shifts to the running state, the on-vehicle PLC communication device6performs a fault diagnosis.

Moreover, if the speed of the vehicle1changes to be smaller than a predetermined value in the running state, the on-vehicle PLC communication device6shifts to the standby state.

Next, the processing to be performed by the on-vehicle PLC communication device6will be described by using flowcharts. It is noted that the processing depicted in the following flowcharts is processing achieved by the control unit61of the on-vehicle PLC communication device6executing the fault diagnosis program61istored in the storage unit61b.

FIG. 5is a flowchart depicting the processing procedure to be performed by the on-vehicle PLC communication device6in the standby state. In the standby state, the control unit61of the on-vehicle PLC communication device6obtains vehicle speed information (step S11) and determines whether or not the speed of the vehicle1is equal to or larger than a predetermined value (step S12).

If the speed of the vehicle1is equal to or larger than the predetermined value (step S12: YES), the control unit61shifts the operating state from the standby state to the running state (step S16) and ends the processing in the standby state.

If the speed of the vehicle1is smaller than the predetermined value (step S12: NO), the control unit61obtains the connection information indicative of the connection state between the charging cable3and the vehicle1(step S13) and determines whether or not the charging cable3is connected to the vehicle1(step S14). If the charging cable3is not connected thereto (step S14: NO), the control unit61returns the processing to step S11. If the charging cable3is connected thereto (step S14: YES), the control unit61shifts the operating state from the standby state to the communication state (step S15) and ends the processing in the standby state.

FIG. 6is a flowchart depicting the processing procedure to be executed by the on-vehicle PLC communication device6in the running state. In this processing, the control unit61uses a diagnosis execution flag indicating whether or not a fault diagnosis has been performed. This diagnosis execution flag is achieved by using, for example, a register or a certain storage area or the like of the storage unit61bcontained in the CPU61aof the control unit61. The diagnosis execution flag indicates that a fault diagnosis has not yet been executed when the value thereof is 0 and indicates that a fault diagnosis has already been executed when the value thereof is 1.

The control unit61of the on-vehicle PLC communication device6having been shifted from the standby state to the running state determines whether or not the standby state has been shifted to the running state (step S21). If it is determined that the standby state has been shifted to the running state (step S21: YES), the control unit61sets the value of the diagnosis execution flag to 0 (step S22). If the processing at step S22is completed, or if it is determined the standby state has not been shifted to the running state (step S21: NO), for example, if it has already been in the running state or if the fault diagnosis state has shifted to the running state, the control unit61obtains the speed information of the vehicle1(step S23) and determines whether or not the speed of the vehicle1is equal to or larger than a predetermined value (step S24). It is noted that the control unit61that performs the processing at step S23functions as a vehicle speed information obtainment unit in the aspect (3).

If the speed of the vehicle1is smaller than the predetermined value (step S24: NO), the control unit61shifts the operating state from the running state to the standby state (step S25) and ends the processing in the running state.

If the speed of the vehicle1is equal to or larger than the predetermined value (step S24: YES), the control unit61determines whether or not the value of the diagnosis execution flag is 0 (step S26). If the value of the diagnosis execution flag is 1 (step S26: NO), that is, if a fault diagnosis has already been executed, the control unit61returns the processing to step S23. If the value of the diagnosis execution flag is 0 (step S26: YES), that is, if a fault diagnosis has not yet been executed, the control unit61shifts the operating state from the running state to the fault diagnosis state (step S27) and ends the processing in the running state.

It is noted that the speed information of the vehicle1is utilized for determining whether or not the vehicle1is running in the above description, but the shift range information of the vehicle1may be utilized in place thereof. If the shift range is “D,” it is determined that the vehicle1is running while if the shift range is “P,” it is determined that the vehicle is not running. In the case where the shift range information is utilized in place of the speed information, this facilitates the determination whereas even in the case where the vehicle1is in a state of the “P” range and braked immediately before the completion of parking of the vehicle1, it may be determined that the vehicle is in a running state, and a fault diagnosis is executed. Accordingly, the speed information allows for more accurate determination than the shift range information as to the situation where a fault diagnosis should be made.

FIG. 7is a flowchart depicting the processing procedure to be executed by the on-vehicle PLC communication device6in the communication state. In the communication state, the control unit61of the on-vehicle PLC communication device6obtains the connection information indicative of the connection state between the vehicle1and the charging cable3(step S31) and determines whether or not the charging cable3is connected to the vehicle1(step S32) based on the signal detected by the connection detecting switch10. If the charging cable3is connected thereto (step S32: YES), the control unit61performs required communication processing concerning charging (step S33) and returns the processing to step S31. If the charging cable3is not connected thereto (step S32: NO), the control unit61shifts the operating state from the communication state to the standby state (step S34) and ends the processing in the communication state.

FIG. 8is a flowchart depicting the processing procedure to be executed by the on-vehicle PLC communication device6in the fault diagnosis state. The control unit61of the on-vehicle PLC communication device6having shifted from the running state to the fault diagnosis state obtains a fault detection signal via the third input/output unit61e(step S41). The control unit61then specifies the waveform of the fault detection signal (step S42) and specifies the cycles thereof (step S43). The control unit61performs a fault diagnosis by searching for the fault location and the content of the fault corresponding to the waveform and the cycles from the fault diagnosis table61hbased on the waveform and the cycles of the fault detection signal specified at steps S42and S43(step S44). The control unit61stores the result of the fault diagnosis at step S44in the storage unit61b(step S45).

Next, the control unit61sets the value of the diagnosis execution flag to 1 (step S46). The control unit61shifts the operating state from the fault diagnosis state to the running state (step S47) and ends the processing in the fault diagnosis state.

The on-vehicle PLC communication device6according to Embodiment 1 configured as described above may detect the fault inside the on-vehicle PLC communication device6and the fault of the connector66. More specifically, the on-vehicle PLC communication device6according to Embodiment 1 may detect the faults of the modem62, the sending pass circuit63b, the sending protection circuit63a, the DC bias cut capacitor C0, the first coupling transformer T1, the first coupling capacitor C1, the first common mode choke coil L1, the connector66, the second common mode choke coil L2, the second coupling capacitor C2, the second coupling transformer T2, the receiving protection circuit63cand the receiving filter circuit63d.

Furthermore, the control unit61may specify the fault location and the content of the fault by using the fault diagnosis table61h.

Moreover, while grasping the communication status, the on-vehicle PLC communication device6may accurately perform a fault diagnosis of the inside of the on-vehicle PLC communication device6and the connector66in the state where communication and detection by a beacon signal are not hindered. For example, the on-vehicle PLC communication device6performs processing while shifting among the four states, the standby state, the running state, the fault diagnosis state and the communication state as communication-related states.

More specifically, since the on-vehicle PLC communication device6performs a fault diagnosis in the state where the charging cable3of the charging station2is not connected to the vehicle1, this prevents the communication and detection by a beacon signal from being hindered by the electronic components constituting the charging station2and charging cable3, so that the on-vehicle PLC communication device6may accurately perform a diagnosis of the fault inside the on-vehicle PLC communication device6and the fault of the connector66.

Moreover, since the on-vehicle PLC communication device6performs a fault diagnosis while the vehicle1is running, it may accurately perform a diagnosis of the fault inside the on-vehicle PLC communication device6and the fault of the connector66under the situation where the communication and detection by the beacon signal are not hindered.

Although the present invention has been described using the embodiment, the technical scope of the present invention is not limited to the scope described in the above-mentioned embodiment. It is to be understood that embodiments obtained by adding many modifications and variations are added to the above-mentioned embodiment will be apparent to those skilled in the art. It will also be obvious from the claims that the technical scope of the present invention encompasses the embodiments to which such modification and variation are added.

While the present invention has been described using, for example, a vehicle in the above-described embodiment, the present invention is applicable to general transportation apparatuses having a driving mechanism a part of which is eclectically operated such as an inverted pendulum mobile unit including an electric motorcycle, a ship, a plane, a personal mobility and an electric motorcycle saddle-ridden by a crew, and it is obvious that these are also included in the technical scope of the present invention.