JP2006007895A - Electric power supply system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric power supply system for a vehicle which can check a state of connection between a power cord and a node, and operating conditions of a load without through the medium of communications system, and can easily perform sensing of the occurrence of an abnormal condition and identification of an abnormal node under normal circumstances. <P>SOLUTION: A plurality of nodes 4a, 4b, 4c, each of which is provided with a load control part 9 for controlling electric loads arranged at the various parts of the vehicle, are each connected to the power cord 1 for supplying power to the load of each node and a multiple transmission cord 2 for transmitting information such as a control signal or the like. Then each node is provided with not only the load control part 9 but also an abnormal current sensing part 5, a sense signal generating part 10, and a switching part 6. When abnormal current is sensed by the abnormal current sensing part 5, a power supply path is switched from a contact 7 to a contact 8 side by the switching part 6. Then a signal is sent out to a signal cable 3 for diagnostic by way of a resistance installed on the sense signal generating part 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a distributed control system that controls loads of various electrical components, devices, equipment, and the like mounted on a vehicle. In particular, the normal operation state of each node and an abnormal node can be easily identified. In addition, the present invention relates to a vehicle power supply system that can easily check a connection between a power supply line and each load node even at startup.

  Recently, the electric load of vehicles has been increasing, and while the power supply system and signal system for electronically controlling the main engine and auxiliary equipment have increased, the front panel economy has been changed to an electronic display system, etc. Many electrical components have been installed. Accordingly, the increase of power supply systems and signal systems has become a major issue, and standardization and rationalization of power supply systems and signal systems are being promoted in order to ensure the reliability. As an example, a CAN (controller area network) system is applied to the backbone as a signal system, while an in-vehicle LAN using a LIN (local interconnect network) system is adopted for terminal communication. The CAN system for the core part is adopting CSMA / CD as a communication method, and standardization is progressing such that each controller performs autonomous distributed control.

  On the other hand, rationalization and standardization are delayed in the vicinity of the vehicle and the like, and particularly in the power supply system, a power line is laid for each individual device to supply power. Therefore, at present, protection means for protecting the power supply is also installed in each power supply line.

  In addition to cases where abnormal current occurs during normal load operation as a failure seen in electric loads, even if it is not operating, the contact between the electric load and the power line is insufficient, etc. There are many problems such as inability to operate at the time when an operation request is made. In order to confirm whether or not each electric load is in an operable state, it is the current situation that an operation request is actually made to confirm whether the electric load can operate normally. When such a check means detects a load that cannot operate normally, it is usually dealt with by replacing electrical equipment or parts of the load. However, in many cases, the true cause is a contact failure between the device and the power line rather than a failure of the device.

  In Japanese Patent Laid-Open No. 57-80239, a power supply line is looped, a current sensor is disposed at least at one location of the power supply line, and when the current sensor detects an abnormal state, the detected state is reported to the central control unit. The central control unit evaluates (specifies) the location of anomaly by sequentially turning on and off multiple power supply control units, and when the location of the anomaly is identified, the technology isolates that part from the power supply loop Is disclosed.

Japanese Patent Laid-Open No. 10-262330 performs information exchange through an adjacent power distribution device and a multiple signal transmission unit, and identifies and eliminates a failure point based on the information.
JP 57-80239 A JP-A-10-262330

    However, standardization and rationalization of the power supply system and signal system have not progressed as much as the main parts of the vehicle's peripheral parts such as doors, roofs, back doors, etc., and it is more difficult to deal with standardization and rationalization of the power supply system. It is a situation. The power supply system is provided with a line for supplying each load individually, and no rationalization has been performed, for example, a fuse is installed in each line as a protection means.

    In addition, the area where the wiring of the power supply system and the signal system can be laid is extremely limited for doors and backdoors, etc., and when the LIN system is applied, the node part where signals are accumulated becomes large and installation space increases. Is difficult to secure.

  In the method disclosed in Japanese Patent Laid-Open No. 57-80239, the configuration of the power supply line avoids the complexity, but there is a problem that it takes a long time to detect the fault and takes too much time to isolate the fault occurrence site. is there.

  In the method disclosed in Japanese Patent Application Laid-Open No. 10-262330, complex logic is used to identify a failure point. Therefore, even for a less important load, all loads connected to the feeder line are used. However, there is a problem that the same function is required.

  As can be seen from the above known examples, the connection state of the load node, abnormality detection, and the like are determined based on the information of each node obtained via the communication system. As described above, information management is performed via the communication system, which causes a complication of the communication process. In addition, when an abnormality occurs in the communication system, the state of the control system may not be grasped. This means that the reliability of the control system depends not only on its own reliability but also on the reliability of the communication system.

  The present invention has been made in view of the above-described circumstances, and can confirm the connection state between the power supply line and the node and the operation state of the load without going through the communication system. An object of the present invention is to provide a vehicle power supply system that can be easily specified.

    According to a first aspect of the vehicle power supply system of the present invention, there are provided a plurality of nodes each provided with a load control unit for controlling an electrical load disposed in various places of the vehicle, and for supplying power to each of the nodes. A power supply system for a vehicle including a plurality of power supply lines and a multiplex transmission line connecting the nodes, wherein each node is arranged on a line that receives power from the power supply line and detects an abnormality in a load current. An abnormal current detector, a detection signal generator that starts receiving power when an abnormality is detected in the abnormal current detector, and sends a weak current as an output signal; and the detection signal generator connected to the detection signal generator A diagnostic signal line shared by each node that transmits a signal from the unit, and a switching unit that switches the power supply from the power line to the load control unit or the detection signal generation unit It is a system.

  A second aspect is the vehicle power supply system, wherein the switching unit provided in each node is connected to the detection signal generating unit side when the load of the node is not operating. .

  According to a third aspect, the detection signal generation unit provided in each node is configured with a resistor having a different magnitude for each node, and an output signal transmitted from the detection signal generation unit varies depending on each node. This is a vehicle power supply system characterized by being made.

  According to a fourth aspect, the detection signal generation unit provided in each of the nodes is configured to detect the output signal transmitted from the detection signal generation unit so that the output signal has a predetermined size predetermined for each node. The power supply system for a vehicle is characterized in that the magnitude of the resistance of the signal generator is set.

  According to a fifth aspect of the present invention, there is provided a vehicle power supply system characterized in that a common diagnostic signal line is not required by connecting the detection signal generation unit provided in each node to an existing multiplex transmission line. is there.

  A sixth aspect is a vehicular power supply system further comprising a display unit that is connected to the diagnostic signal line and displays a signal transmitted from the detection signal generation unit of each node.

  In a seventh aspect, the vehicle further includes an abnormal node determination unit that is connected to the diagnostic signal line and determines an abnormal node based on a signal transmitted from the detection signal generation unit of each node. Power supply system.

  The eighth aspect is a node connected to the diagnostic signal line and diagnosing the connection state between each of the nodes and the power supply line based on a signal transmitted from the detection signal generator when the battery is connected or the engine is started. The vehicle power supply system further includes a connection diagnosis unit.

  The ninth aspect further includes a load monitoring unit that is connected to the diagnostic signal line and that monitors whether or not the load of each node is in operation based on a signal transmitted from the detection signal generation unit during normal operation. This is a vehicle power supply system.

  According to the present invention, when an abnormal current is detected by the abnormal current detection unit of any node during normal operation, the switching unit of the node is switched from power supply to the load to power supply to the detection signal generation unit of the node. As a result, a predetermined output signal is provided from the detection signal generation unit to the driver via the diagnostic signal line, so that the driver can immediately know the occurrence of the abnormality and the location where the abnormality has occurred. There is an effect. In addition, by using a common diagnostic signal line, it can be realized without increasing the load on the multiplex transmission line and the multiplex transmission apparatus, and even when an abnormality occurs in the multiplex transmission line, the power supply state to each node is confirmed. There is an excellent effect of being able to.

  Further, according to the present invention, in the vehicle power supply system according to claim 1, when the load is inoperative, the load is inoperative by connecting the switching unit of the node to the detection signal generating unit side. Even if it exists, there exists the outstanding effect that it can confirm that the said node is supplying electric power normally.

  Furthermore, according to the present invention, in the vehicle power supply system according to claim 1 and claim 2, by setting the magnitude of the resistance of the detection signal generation unit of each node to a different value unique to each node, There is an excellent effect that it is possible to determine a node where an abnormality has occurred based on a signal transmitted from a detection signal generation unit via a diagnostic signal line in the event of an abnormality.

  Furthermore, according to the present invention, in the vehicle power supply system according to claim 1 or 2, the signal transmitted from the detection signal generator of each node via the diagnostic signal line has a predetermined value. By setting the magnitude of the resistance of the detection signal generation unit of each node, there is an excellent effect that it becomes easy to identify an abnormal node when an abnormality occurs.

  Furthermore, according to the present invention, the detection signal generation unit of each node is connected to the multiplex transmission line, and the output signal from the detection signal generation unit is transmitted via the multiplex transmission line, so that the common diagnostic use There is an excellent effect that not only the signal line is unnecessary and the cost is reduced but also the wiring volume can be reduced.

  Furthermore, according to the present invention, by adding a display unit for displaying the output signal from the detection signal generation unit of each node, the load operation / non-operation state of each node, the connection state between the power line and each node, etc. It is possible to provide a driver with a display method that can be easily recognized.

  Furthermore, according to this invention, the driver can recognize the abnormal node immediately and reliably by adding the abnormal node determination unit that determines the abnormal node based on the output signal from the detection signal generation unit of each node. Has an excellent effect.

  Furthermore, according to the present invention, by adding the node connection diagnosis unit, the driver can check the connection state between each node and the power supply line before traveling, and the electric load particularly necessary for safe traveling is normally supplied with power. There is an excellent effect that it can be easily confirmed whether the vehicle is running or not.

  Further, according to the present invention, by adding the load monitoring unit, the driver can check whether or not the load of each node is operating even while traveling, and particularly the electrical load necessary for safe traveling operates normally. There is an excellent effect that it can be easily confirmed whether or not the

Embodiments of a vehicle power supply system according to the present invention will be described with reference to the accompanying drawings.
According to a first aspect of the vehicle power supply system of the present invention, there are provided a plurality of nodes each provided with a load control unit for controlling an electrical load disposed in various places of the vehicle, and a power source for supplying power to each node. A power supply system for a vehicle including a power supply line and a multiplex transmission line connecting each node, and an abnormal current detection unit that is disposed on a line that receives power supply from the power supply line at each node and detects a load current abnormality A detection signal generator that starts receiving power when an abnormality is detected in the abnormal current detector and sends a weak current as an output signal; and a signal from the detection signal generator is transmitted by connecting to the detection signal generator The vehicle power supply system includes a common diagnostic signal line and a switching unit that switches power supply from the power supply line to the load control unit or the detection signal generation unit.

  FIG. 1 is a diagram illustrating the overall configuration of the first aspect of the vehicle power supply system of the present invention. Each of the plurality of nodes 4a, 4b, and 4c includes a load control unit 9 for controlling an electric load disposed in each part of the vehicle, and a power line 1 for supplying power to the load of each node and Each is connected to a multiplex transmission line 2 for transmitting information such as a control signal. Each node is provided with an abnormal current detection unit 5, a detection signal generation unit 10, and a switching unit 6 in addition to the load control unit 9.

  The abnormal current detector 5 is disposed on a line that receives power from the power line 1 and monitors the occurrence of an abnormal excessive current. The abnormal current detection unit 5 is formed of a resistor on the order of mΩ, for example. The switching unit 6 is connected to the contact 8 side in the initial state or when the node is stationary, and is connected to the contact 7 side during normal operation. When the abnormal current detection unit 5 detects an abnormality in the load current, the switching unit 6 is connected to the contact 8 side. Switch the power supply path. The detection signal generator 10 is composed of a resistor having a resistance value sufficiently larger than the resistance component of the abnormal current detector 5 (for example, kΩ order), its input side is a contact 8 of the switch 6, and its output side is for diagnosis. It is connected to the signal line 3. In the vehicle power supply system of the present invention, in addition to the power supply line 1, the multiple signal line 2, and the diagnostic signal line 3, a ground line (not shown) exists. In addition, at least one end side (for example, the left side in FIG. 1) of these wirings is connected to a multiplex transmission apparatus (not shown).

  In the initial state, the power supply path is connected to the contact 8 side by the switch 6, and when an abnormal current is detected by the abnormal current detection unit 5, the power supply path is switched from the contact 7 to the contact 8 side by the switch 6. By switching to, the detection signal generator 10 starts receiving power. When the detection signal generator 10 starts receiving power, a weak current is sent as an output signal to the diagnostic signal line 3 via a resistor installed in the detection signal generator 10. The common diagnostic signal line 3 is connected to the output side of the detection signal generation unit 10 of each node. When an abnormal current is detected by the abnormal current detection unit 5 of any node, the common diagnostic signal line 3 A signal is sent to 3. The common diagnostic signal line 3 is grounded via a predetermined bias resistor 11.

    The operation of the vehicle power supply system configured as described above will be described below. When the load fed from the node 4a is in operation, the switching unit 6 of the node is in a closed state on the contact 7 side connected to the load control unit 9, and the load control unit 9 is fed. Here, when an abnormality occurs in the load fed from the node 4a and an abnormal current flows, the abnormal current detection unit 5 of the node 4a detects this and instructs the switching unit 6 of the node to switch. The switching unit 6 switches the power feeding path from the contact 7 to the contact 8 in response to an instruction from the abnormal current detection unit 5 and starts power feeding to the detection signal generation unit 10. When power is supplied to the detection signal generation unit 10, a current passing through the resistance of the detection signal generation unit 10 is sent to the diagnostic signal line 3. Since the diagnostic signal line 3 is biased by the predetermined resistor 11, it is possible to detect the occurrence of an abnormal current by measuring the potential of the diagnostic signal line 3.

  According to a second aspect of the vehicle power supply system of the present invention, the switching unit provided in each node is connected to the detection signal generating unit side when the load of the node is not operating. This is a vehicle power supply system.

  FIG. 2 is a diagram illustrating a second aspect of the vehicle power supply system of the present invention. In the figure, when the load controlled by the node 4b is not operating, the switching section 6 of the node 4b connects the power supply path to the contact 8 side. As a result, when the load is inoperative, a signal is sent from the detection signal generator 10 of the node 4b to the diagnostic signal line 3, and the load is inoperative by measuring the potential of the diagnostic signal line 3. It becomes possible to determine that it is in the middle. In addition, when the signal connected to the node 4b is not operating and no signal is transmitted from the detection signal generator 10 of the node 4b, the connection between the node 4b and the power supply line is poor. It can be determined that there is. By connecting each of the nodes 4a, 4b, and 4c to the power supply line 1 and the diagnostic signal line 3 with an integrated connector, only the connection between each of the nodes 4a, 4b, and 4c and the diagnostic signal line 3 becomes defective. The situation can be avoided.

  According to a third aspect of the vehicle power supply system of the present invention, the detection signal generation unit provided in each node is configured with resistors having different sizes for each node, and the output signal sent from the detection signal generation unit is The power supply system for a vehicle is characterized in that it has different sizes depending on nodes.

  A third aspect according to the present invention will be described with reference to FIGS. In the present invention, the resistance installed in the detection signal generation unit 10 is set to a specific size that is different for each node. Furthermore, even when signals are simultaneously output from the detection signal generation units 10 of a plurality of nodes, the resistance of the detection signal generation unit 10 of each node is set so that the node outputting the signal can be individually identified. It is set. The upper part of FIG. 3 shows the equivalent circuit of FIG. 1, where RL is the resistance value of the abnormal current detector 5, Ra, Rb, Rc are the resistance values of the detection signal generators 10 at the nodes 4a, 4b, 4c, respectively. Rs indicates the resistance value of the bias resistor 11. Here, it is assumed that the resistance value of the abnormal current detection unit 5 at each node is equal.

  The lower part of FIG. 3 shows an equation for calculating the potential difference Vs of the bias resistor 11 in the equivalent circuit of the upper part of the figure. However, since the resistance RL of the abnormal current detection unit 5 is sufficiently smaller than the resistances Ra, Rb, and Rc of the detection signal generation unit 10, RL is ignored in the calculation formula of Vs. The calculation formula of Vs is a calculation formula of Vs when all the signals are output from the detection signal generation units 10 of the nodes 4a, 4b, and 4c, and it is assumed that a signal is output from the detection signal generation unit 10 of the node 4a. Is not output, Vs is calculated when signals are output from the detection signal generators 10 of the nodes 4b and 4c by deleting the Ra term included in the Vs calculation formula. be able to. Therefore, the magnitude of the resistance of each detection signal generation unit 10 at each node is set so that each Vs calculated for every combination of nodes outputting signals from the detection signal generation unit 10 has a different value. Can be determined. For example, if the resistances of Ra, Rb, and Rc are 1: 2: 4, each Vs calculated for every combination of nodes that output signals from the detection signal generator 10 is different. Value. Accordingly, it is possible to determine from which node the signal is output by monitoring Vs.

  According to a fourth aspect of the vehicle power supply system of the present invention, the detection signal generator provided in each node has an output signal sent from the detection signal generator having a predetermined magnitude predetermined for each node. Thus, the vehicle power supply system is characterized in that the magnitude of the resistance of the detection signal generator is set.

  A fourth aspect according to the present invention will be described with reference to FIGS. As described in the third aspect, by appropriately setting the magnitude of the resistance installed in each detection signal generation unit 10 of each node, the node in which the potential difference Vs of the bias detection signal generation unit 11 is abnormal or inoperative The magnitudes of the resistances Ra, Rb, and Rc of the detection signal generator at each node can be determined so as to be all different depending on the combination. In the fourth mode, the magnitudes of the resistances Ra, Rb, and Rc of the detection signal generation units at each node are set so that the potential difference Vs of the bias detection signal generation unit 11 becomes a predetermined level depending on the combination of abnormal or non-operational nodes. It is the one that decides. An example of the magnitude of Vs is shown in FIG. In FIG. 4, Vs is in the range of 28 when all the loads of the nodes 4a, 4b, and 4c are operating normally, and Vs is in the range of 21 when all the loads on each node are abnormal or inoperative. It shows that there is. Similarly, when the load of some nodes is abnormal or inoperative, the magnitudes of Ra, Rb, and Rc are set so that Vs falls within the range of 22 to 27 depending on the combination of abnormal nodes. This makes it easy to determine an abnormal or non-operational node.

  A fifth aspect of the vehicle power supply system of the present invention is characterized in that a common diagnostic signal line is not required by connecting a detection signal generator provided in each node to an existing multiplex transmission line. This is a vehicle power supply system.

  A fifth aspect according to the present invention will be described with reference to FIG. In FIG. 5, the signal of the detection signal generation unit 10 of each node is output to the existing multiplex transmission line 2. This eliminates the need for a common diagnostic signal line, thereby reducing the cost and the wiring volume. In FIG. 5, illustration of the path between each node for transmitting information such as a control signal and the multiplex transmission line 2 is omitted.

  According to a sixth aspect of the vehicle power supply system of the present invention, a vehicle power supply characterized in that a display unit connected to the diagnostic signal line and displaying a signal transmitted from the detection signal generation unit of each node is added. System.

  A sixth aspect according to the present invention will be described with reference to FIG. In the present invention, a display unit (not shown) for displaying a signal transmitted from the detection signal generation unit 10 of each node is added, and the display unit is connected to the diagnostic signal line 3. By installing the display unit on the front panel or the like, the driver's cognition can be enhanced. Further, by displaying the potential difference according to the third aspect or the fourth aspect of the present invention on the display unit, the driver's cognition can be further enhanced.

  According to a seventh aspect of the vehicle power supply system of the present invention, an abnormal node determination unit (not shown) is connected to the diagnostic signal line and determines an abnormal node based on a signal transmitted from the detection signal generation unit of each node. ) Is added to the vehicle power supply system.

  A seventh aspect according to the present invention will be described with reference to FIG. In the present invention, an abnormal node determination unit is added. The abnormal node determination unit is connected to the diagnostic signal line 3, and determines an abnormal node based on a signal transmitted from the detection signal generation unit 10 of each node and notifies the driver.

  A means for determining an abnormal node will be described below. As described in the third aspect or the fourth aspect of the present invention, the bias detection signal generation unit 11 is based on the combination of nodes that are determined to be abnormal by the abnormal current detection unit 5 and the signal is output from the detection signal generation unit 10. The resistance of the detection signal generator 10 at each node is set so that the potential differences at all are different. The abnormal node determination unit stores all the potential differences of the bias detection signal generation unit 11 that are different depending on the combination of nodes determined to be abnormal, and compares the stored potential difference with the actual potential difference of the bias detection signal generation unit 11. To determine the abnormal node. As a result, the driver can quickly and accurately determine the abnormal node.

  The eighth aspect of the vehicle power supply system of the present invention is based on a signal that is connected to a diagnostic signal line and transmits a connection state between each node and a power line when a battery is connected or an engine is started. The vehicle power supply system is characterized in that a node connection diagnosis unit for diagnosis is added.

  An eighth aspect according to the present invention will be described with reference to FIG. In the present invention, a node connection diagnosis unit (not shown) is added. The node connection diagnostic unit is connected to the diagnostic signal line 3, and based on the signal transmitted from the detection signal generation unit 10 of each node, the connection between each node and the power line 1 is established when the battery is connected or when the engine is started. I try to diagnose the condition.

  The diagnostic means of the node connection diagnostic unit will be described below. When the load connected to each node is not in operation, the switching unit 6 of the node connects the power feeding path to the contact 8 side. Most of the load is inactive when the battery is connected or immediately after the engine is started. Therefore, whether or not a signal is transmitted from all nodes of the load that is inoperative at that time based on a signal transmitted via the diagnostic signal line 3 immediately after the battery is connected or immediately after the engine is started. Diagnose. As a result, when it is determined that no signal is transmitted from the detection signal generators 10 of some nodes, the node that does not transmit the signal is identified. For example, a node determined not to send a signal is highly likely to have an abnormal connection with the power supply line 1.

According to a ninth aspect of the vehicle power supply system of the present invention, the load is connected to the diagnostic signal line and monitors whether or not the load of each node is operating based on the signal transmitted from the detection signal generating unit during normal operation. The power supply system for a vehicle is characterized in that a monitoring unit is added.
A ninth aspect of the present invention will be described with reference to FIG. In the present invention, a load monitoring unit (not shown) is added. The load monitoring unit is connected to the diagnostic signal line 3 so that it can monitor whether or not the load of each node is operating at the normal time based on the signal transmitted from the detection signal generating unit 10 of each node. Yes.

  The load monitoring means by the load monitoring unit will be described below. When the load connected to each node does not operate, the switching unit 6 of the node connects the power feeding path to the contact 8 side. As a result, a signal from the detection signal generation unit 10 is sent to the diagnostic signal line 3 from a node where the load is not operated. Therefore, based on the signal sent via the diagnostic signal line 3 , It is possible to determine a node of a load that is inactive. By adding the load monitoring unit, when the load to be operated is non-operation, this can be recognized quickly.

  In addition, the description in this Embodiment shows an example of the electric power feeding system for vehicles which concerns on this invention, and is not limited to this. The detailed configuration and detailed operation of the vehicle power supply system in the present embodiment can be changed as appropriate without departing from the spirit of the present invention.

FIG. 1 is a diagram illustrating the overall configuration of a vehicle power supply system according to the present invention. FIG. 2 is a diagram illustrating the operation of the switching unit when some of the loads are non-operational in the overall configuration diagram illustrated in FIG. 1. FIG. 3 is a diagram showing an equivalent circuit of the overall configuration shown in FIG. 1 and a potential difference calculation formula. FIG. 4 is a diagram illustrating an example of a difference in detected potential depending on a combination of nodes where an abnormal current is detected. FIG. 5 is a diagram showing the overall configuration of the vehicle power supply system of the present invention when a multiplex transmission line is used instead of the diagnostic signal line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Power supply line 2 ... Multiplex transmission line 3 ... Diagnosis signal line 4a, 4b, 4c ... Node 5 ... Abnormal current detection part 6 ... Switching part 7, 8 ... Contact 9 ... Load control unit 10 ... Detection signal generator 11 ... Bias resistor

Claims (9)

Multiple nodes each having a load control unit for controlling an electrical load disposed at various locations of the vehicle, a power line for supplying power to each node, and multiplex transmission for connecting the nodes A power supply system for a vehicle comprising a wire,
An abnormal current detection unit that is disposed on a line that receives power from the power supply line at each node and detects an abnormality in the load current, and starts receiving power and outputs a weak current when an abnormality is detected in the abnormal current detection unit A detection signal generating unit to be transmitted as a signal, a diagnostic signal line connected to each node connected to the detection signal generating unit and transmitting a signal from the detection signal generating unit, and a power supply from the power supply line to the load A vehicular power supply system comprising a switching unit that switches to a control unit or the detection signal generation unit. 2. The vehicle power supply system according to claim 1, wherein the switching unit provided in each of the nodes is connected to the detection signal generating unit when a load of the node is not operating. 3. The detection signal generation unit provided in each node is configured with a resistor having a different magnitude for each node, and an output signal transmitted from the detection signal generation unit has a different magnitude depending on each node. The power feeding system for a vehicle according to claim 1 or 2, characterized by the above. The detection signal generation unit provided in each node has a resistance of the detection signal generation unit so that an output signal transmitted from the detection signal generation unit has a predetermined magnitude predetermined for each node. The vehicle power supply system according to claim 1 or 2, wherein a size is set. The power supply system for a vehicle according to claim 1 or 2, wherein the detection signal generator provided in each node is connected to an existing multiple transmission line. The vehicle power supply system according to claim 1, further comprising a display unit that is connected to the diagnostic signal line and displays a signal transmitted from the detection signal generation unit of each of the nodes. . 3. An abnormal node determination unit that is connected to the diagnostic signal line and determines an abnormal node based on a signal transmitted from the detection signal generation unit of each node. The vehicle power supply system described in 1. A node connection diagnosis unit which is connected to the diagnosis signal line and diagnoses a connection state between each node and the power supply line based on a signal transmitted from the detection signal generation unit when the battery is connected or when the engine is started; The vehicle power supply system according to claim 1 or 2, wherein the power supply system is a vehicle power supply system. A load monitoring unit that is connected to the diagnostic signal line and that monitors whether or not the load of each node is operating normally is based on a signal transmitted from the detection signal generation unit. The vehicle power supply system according to claim 1 or 2.

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