JP2022110277A - Diagnosis system for wiring deterioration in wiring harness - Google Patents

Abstract

To provide a wiring deterioration diagnostic system in a wire harness capable of easily diagnosing deterioration of wiring in the wire harness.SOLUTION: A wiring deterioration diagnostic system 1 in a wire harness includes: a plurality of sensors 11A to 11E; a controller 17 for receiving signals output from the plurality of sensors; a common source line 12P and a common ground line 12G for supplying power to the plurality of sensors; connection wirings 13 to 16 in the wire harness for electrically connecting the plurality of sensors and the source line 12P, and the plurality of sensors and the ground line 12G, respectively; and a wiring deterioration diagnostic part 21. The wiring deterioration diagnostic part 21 in the wire harness diagnoses deterioration of the connections 13 to 16 in the wire harness based on at least one of the high voltage abnormality and the low voltage abnormality of the signals output from the plurality of sensors.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wiring deterioration diagnostic system in a wire harness.

Wire harnesses used in vehicles such as construction machines are required to have high conduction reliability. Therefore, a technology has been proposed for detecting in advance a conduction failure due to aged deterioration and maintaining conduction reliability. For example, it is conceivable to apply the technology for detecting connection deterioration between connection terminals inside a connector described in Patent Document 1 to a wire harness.

JP 2017-188286 A

However, although the technique described in Patent Literature 1 can detect deterioration over time due to plugging and unplugging of connectors, it is difficult to apply the technology to wire harnesses in which plugging and unplugging of connectors is rarely performed. That is, in the case of a wire harness in which a plurality of electric wires (wiring) are bundled, the branched portion of the electric wire including the connector is hardly inserted and removed, and the branched portion of the electric wire is covered with tape, protective material, etc. It is in a state where it cannot be seen from For this reason, it is difficult to grasp the progress of aged deterioration. In addition, in the case of aged deterioration due to environmental factors such as moisture, dust, vibration, and shock, it is difficult to recognize initial abnormalities such as conduction failures that occur instantaneously or temporarily.

SUMMARY OF THE INVENTION In view of the circumstances described above, it is an object of the present invention to provide a wiring deterioration diagnostic system in a wire harness that can easily diagnose deterioration of wiring in a wire harness.

A wiring deterioration diagnosis system in a wiring harness according to the present invention includes a plurality of sensors, a controller that receives signals output from the plurality of sensors, a common power line that supplies power to the plurality of sensors, and a common ground. a wire, a wire harness for electrically connecting the plurality of sensors and the power supply line, and the plurality of sensors and the ground line, respectively, and a high voltage abnormality and a low voltage abnormality of the signals output from the plurality of sensors. and a wiring deterioration diagnostic unit in the wiring harness for diagnosing deterioration of the wiring in the wiring harness based on at least one of the above.

In the wiring deterioration diagnosis system in the wire harness according to the present invention, the wiring deterioration diagnosis part in the wire harness detects the wiring in the wire harness based on at least one of the high voltage abnormality and the low voltage abnormality of the signals output from the plurality of sensors. deterioration can be easily diagnosed.

ADVANTAGE OF THE INVENTION According to this invention, deterioration of wiring in a wire harness can be diagnosed easily.

1 is a schematic configuration diagram showing a wiring deterioration diagnostic system in a wire harness according to an embodiment; FIG. FIG. 4 is a circuit diagram showing connections between a controller and sensors in the construction machine; FIG. 4 is a diagram showing the relationship between sensor output potential and mutation amount; 4 is a flow chart showing a voltage abnormality determination of a sensor output signal by a controller; 5 is a flow chart showing deterioration diagnosis of wiring in the wire harness by the wiring deterioration diagnosis unit in the wire harness of the server; It is a figure which shows the example of a high voltage abnormality table. It is a figure which shows the example of a low-voltage abnormality table. and FIG. 11 is a schematic configuration diagram showing a modification of the wiring deterioration diagnosis system in the wire harness. FIG. 10 is a circuit diagram showing a modification of the wiring deterioration diagnostic system in the wire harness; FIG. 10 is a circuit diagram showing a modification of the wiring deterioration diagnostic system in the wire harness;

An embodiment of a wiring degradation diagnostic system in a wire harness according to the present invention will be described below with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a schematic configuration diagram showing a wiring degradation diagnostic system in a wire harness according to an embodiment. A wiring deterioration diagnosis system 1 in a wire harness according to the present embodiment includes a plurality of construction machines 10 (10A to 10N), a server 20 configured to be able to communicate with each of these construction machines via a network 40, and a network 40. and a database 30 that stores each data transmitted from these construction machines via.

The construction machine 10 exists as a node in the wiring deterioration diagnostic system 1 in the wire harness, and is composed of, for example, a hydraulic excavator, and is used by a predetermined user at a work site where civil engineering work, construction work, demolition work, dredging work, etc. are performed. used for In the present embodiment, the construction machine 10 is exemplified as a node of the wiring deterioration diagnosis system 1 in the wire harness, but a forklift, an automobile, a bus, a ship, an airplane, or the like may be used. Moreover, the construction machine may be a wheel loader, a bulldozer, or the like, in addition to the hydraulic excavator.

FIG. 2 is a circuit diagram showing connections between a controller and sensors in a construction machine. The construction machine 10 is equipped with a plurality of (here, five) sensors 11A to 11E for detecting the ground angle, turning angle, pressure, and the like. Power is supplied to these sensors 11A to 11E via a common power supply line 12P and a common ground line 12G.

More specifically, among the five sensors 11A to 11E, the power supply sides of the sensors 11A to 11C are electrically connected to the power supply line 12P via the connection 13 in the wire harness, and the ground sides of the sensors 11A to 11C are connected to the wire harness. It is electrically connected to the ground line 12G via a connection line 14 inside. The remaining sensors 11D and 11E are electrically connected on the power supply side to the power supply line 12P via connection 15 in the wire harness, and are electrically connected to the ground line 12G via connection 16 in the wire harness on the ground side. It is connected to the. The sensors 11A to 11E are arranged upstream of the sensors 11D and 11E. Note that connection here has the same meaning as wiring.

A wire connection 13 in the wire harness has a branch portion 13A connected to the power line 12P and a branch portion 13B for bundling three electric wires respectively connected to the sensors 11A to 11C. The branching portion 13A and the branching portion 13B are each configured by a crimping portion for crimping electric wires, a crimping portion for bundling electric wires, a branch connector, or the like. A wire connection 14 in the wire harness has a branch portion 14A connected to the ground wire 12G and a branch portion 14B bundling three electric wires respectively connected to the sensors 11A to 11C. The branching portion 14A and the branching portion 14B are each configured by a crimping portion for crimping an electric wire, a crimping portion for fixing an electric wire, a branch connector, or the like.

A wire connection 15 in the wire harness has a branch portion 15A connected to the power line 12P, and a branch portion 15B for bundling two electric wires respectively connected to the sensors 11D and 11E. The branching portion 15A and the branching portion 15B are each configured by a crimping portion for crimping electric wires, a crimping portion for bundling electric wires, a branch connector, or the like. A wire connection 16 in the wire harness has a branch portion 16A connected to the ground wire 12G and a branch portion 16B bundling two electric wires respectively connected to the sensors 11D and 11E. The branching portion 16A and the branching portion 16B are each configured by a crimping portion for crimping an electric wire, a crimping portion for fixing an electric wire, a branch connector, or the like.

The construction machine 10 also includes a controller 17 that controls the entire machine. The controller 17 includes, for example, a CPU (Central Processing Unit) that executes calculations, a ROM (Read Only Memory) as a secondary storage device that stores programs for calculations, and storage of calculation progress and temporary control variables. It is composed of a microcomputer combined with a RAM (Random Access Memory) as a temporary storage device, and performs each control process by executing a stored program.

For example, the controller 17 receives detection results output from the sensors 11A to 11E, and controls excavation, turning, traveling, and the like based on the received results. The controller 17 is connected to the sensors 11A to 11E via signal lines 18 and receives signals output from the sensors 11A to 11E. The sensors 11A to 11E output the detected results to the controller 17 via the signal line 18. FIG.

Further, the controller 17 determines whether or not there is a high voltage abnormality or a low voltage abnormality in the sensor output signals based on the output signals from the sensors 11A to 11E. More specifically, for example, in the wire harness connected to the power supply line 12P, when the contact resistance of the branch portion 13A increases due to corrosion or wear (in other words, when the connection 13 in the wire harness deteriorates), the sensor 11A Since the outputs from 11C to 11C are drawn to the low potential level side, low voltage abnormalities are likely to occur. At this time, since the sensor 11D and the sensor 11E are arranged on the downstream side of the branch portion 13A, their respective outputs are also attracted to the low potential level side, and the low voltage abnormality is likely to occur.

In addition, when the contact resistance of the branch portion 13B increases due to corrosion or wear (in other words, when the connection 13 in the wire harness deteriorates), the outputs from the sensors 11A to 11C are pulled toward the low potential level side. Voltage abnormalities are more likely to occur. On the other hand, the sensors 11D and 11E are connected to the power supply line 12P via the connection 15 in the wiring harness different from the sensors 11A to 11C, so they are not affected by the contact resistance of the branch 13B.

In the wire harness connected to the ground wire 12G, when the contact resistance of the branch portion 14A increases due to corrosion or wear (in other words, when the connection 14 in the wire harness deteriorates), the outputs from the sensors 11A to 11C become high. Since it is attracted to the potential level side, a high voltage abnormality is likely to occur. At this time, the outputs of the sensors 11D and 11E are also drawn to the high potential level side, so a high voltage abnormality is likely to occur.

In addition, when the contact resistance of the branch portion 14B increases due to corrosion or wear (in other words, when the connection 14 in the wire harness deteriorates), the outputs from the sensors 11A to 11C are attracted to the high potential level side. Voltage abnormalities are more likely to occur. On the other hand, the sensors 11D and 11E are connected to the ground line 12G via the connection 16 in the wire harness different from that of the sensors 11A to 11C, so they are not affected by the contact resistance of the branch 14B.

FIG. 3 is a diagram showing the relationship between the sensor output potential and the amount of mutation. In FIG. 3, the horizontal axis indicates the amount of mutation, and the vertical axis indicates the sensor output potential. A hatched area close to the ground potential (GND potential) is a low voltage abnormality diagnosis area, and a hatched area close to the power supply potential is a high voltage abnormality diagnosis area. The shaded area is the sensor output range during normal operation. Therefore, a low voltage abnormality occurs when the output potential of each sensor enters the low voltage abnormality diagnosis region, and a high voltage abnormality occurs when it enters the high voltage abnormality diagnosis region.

Also, the controller 17 transmits each information to the database 30 of the server 20 via the communication unit 19 and the network 40 . For example, the controller 17 periodically (for example, once a day) transmits to the database 30 operation information including the number of days and hours of operation of the construction machine 10, voltage abnormality information of the sensor output signal, and the like. The database 30 stores each information transmitted from the controller 17 . Note that the network 40 may be wireless or wired.

The server 20 is a main computer that constitutes the wiring deterioration diagnostic system 1 in the wiring harness, and is installed in the head office, branch office, factory, or management center of the manufacturer of the construction machine 10 , and receives operation information, etc. from each of the plurality of construction machines 10 . are periodically collected, and these construction machines 10 are centrally managed. The server 20 includes, for example, a CPU (Central Processing Unit) that executes calculations, a ROM (Read Only Memory) as a secondary storage device that stores programs for calculations, and storage of calculation progress and temporary control variables. It is composed of a microcomputer combined with a RAM (Random Access Memory) as a temporary storage device, and performs each process by executing a stored program.

Although the database 30 is provided separately from the server 20 in this embodiment, it may be provided inside the server 20 .

The server 20 also has an internal wire harness wiring deterioration diagnostic unit 21 . The wiring deterioration diagnostic unit 21 in the wiring harness diagnoses the deterioration of the connections 13 to 16 in the wiring harness based on at least one of the high voltage abnormality and the low voltage abnormality of the sensor output signal transmitted from each construction machine 10. . More specifically, the wiring deterioration diagnosis unit 21 in the wire harness detects a state in which a plurality of high voltage abnormalities or low voltage abnormalities have occurred at the same time among the high voltage abnormalities and low voltage abnormalities of the output signals of the sensors 11A to 11E. Deterioration of the connections 13 to 16 in the wire harness is diagnosed based on the number of occurrences at the same time.

Hereinafter, the control processing regarding the voltage abnormality determination of the sensor output signal by the controller will be described with reference to FIG. The control process shown in FIG. 4 targets all the sensors attached to the construction machine 10 and is repeatedly executed at a predetermined cycle.

First, in step S10, parameters are initialized. At this time, the controller 17 controls the sensor output signal variable S[n], sensor output signal high voltage abnormality variable D_high_S[n], sensor output signal low voltage abnormality variable D_low_S[n], sensor output signal voltage abnormality detection time YH_clock[n ] are initialized respectively.

In step S11 following step S10, the signal of sensor i is taken into S[i], where i=i+1. In step S12 following step S11, the controller 17 determines whether i=n. Then, if it is determined that i=n is not true, the control process returns to step S11. On the other hand, if it is determined that i=n, the control process proceeds to step S13.

In step S13, the controller 17 determines whether S[i]>S_high. S_high is a high voltage abnormality threshold preset based on FIG. 3 and stored in the storage device of the controller 17 . Then, when it is determined that S[i]>S_high, the control process proceeds to step S14. In step S14, the controller 17 determines that the sensor output signal has a high voltage abnormality. On the other hand, if it is determined that S[i]>S_high is not true, the process proceeds to step S15.

In step S15, the controller 17 determines whether S[i]<S_low. S_low is a low voltage abnormality threshold preset based on FIG. 3 and stored in the storage device of the controller 17 . Then, when it is determined that S[i]<S_low, the control process proceeds to step S16. In step S16, the controller 17 determines that the sensor output signal has a low voltage abnormality. On the other hand, if it is determined that S[i]<S_low, the process proceeds to step S17.

In step S17 following step S14 or step S16, the controller 17 measures sensor output signal voltage abnormality detection time D[i]. Here, the controller 17 measures the sensor output signal voltage abnormality detection time by setting D[i]=clock[i].

In step S18 following step S17, the controller 17 determines whether i=n. Then, if it is determined that i=n is not true, the control process returns to step S13. On the other hand, if it is determined that i=n, the control process proceeds to step S19.

In step S19, the controller 17 stores the sensor output signal voltage abnormality (high voltage abnormality or low voltage abnormality) S[i] and the sensor output signal voltage abnormality detection time D[i] as a set in the storage device of the controller 17. . This completes the voltage abnormality determination process for the sensor output signal.

The controller 17 periodically (for example, once a day) transmits S[i] and D[i] stored in the storage device to the database 30 on the server 20 side. Specifically, the controller 17 reads out the stored S[i] and D[i], performs a predetermined filtering process, and then converts the process result into construction machine ID (hereinafter referred to as node ID) information. At the same time, it is uploaded to the database 30 on the server 20 side via the communication unit 19 and the network 40 .

Next, deterioration diagnosis of wiring in the wire harness by the wiring deterioration diagnosis unit 21 in the server 20 will be described with reference to FIGS. 5 to 7. FIG. FIG. 5 is a flowchart showing deterioration diagnosis of wiring in the wire harness by the wiring deterioration diagnosis unit in the wire harness of the server. The control process shown in FIG. 5 targets all the construction machines 10 managed by the server 20 and is repeatedly executed at a predetermined cycle for all wire harnesses attached to each construction machine 10 .

First, in step S20, the wiring deterioration diagnostic unit 21 in the wire harness, based on the sensor output signal voltage abnormality S[i] and the sensor output signal voltage abnormality detection time D[i] transmitted from each construction machine 10, performs the following A high-voltage abnormality diagnosis table DSH_TBL of records consisting of fields shown in (1) to (8) is created, and the data abnormality diagnosis record for the most recent predetermined period of the abnormality diagnosis result database performed by the wiring deterioration diagnosis unit 21 in the wire harness Using a character string combining (1) and (2) below as a search key, the results of searching (3) to (7) below are applied to the corresponding fields of the table DSH_TBL.
(1) the node ID associated with the high voltage fault;
(2) The time when the node ID high voltage abnormality occurred (3) High voltage abnormality diagnosis result of the sensor 11A output signal searched by the combination of (1) and (2) above,
(4) High voltage abnormality diagnosis result of the sensor 11B output signal searched by the combination of (1) and (2) above,
(5) high voltage abnormality diagnosis result of the sensor 11C output signal retrieved by the combination of (1) and (2) above;
(6) high voltage abnormality diagnosis result of the sensor 11D output signal retrieved by the combination of (1) and (2) above;
(7) high voltage abnormality diagnosis result of the sensor 11E output signal retrieved by the combination of (1) and (2) above;
(8) Diagnosis result of deterioration of wiring in wiring harness related to high voltage abnormality.

Next, the wiring deterioration diagnostic unit 21 sorts the records of the created table DSH_TBL in ascending order of priority of “node ID” and “occurrence time”, and then sorts the result to the first A consecutive number is assigned to the field "No." starting from 1 in order from the record. Subsequently, the wire harness deterioration diagnosis unit 21 calculates the number of node IDs excluding duplication of "node IDs" from the number of records in the table DSH_TBL, defines and sets the value as H_Node_ID_Max, and also sets the value as H_Node_ID_Max. Define and set the IDs in order as the high voltage abnormal node ID array H_Node_ID[H_Node_ID_Max].

FIG. 6 shows, for example, the high-voltage abnormality table created in step S20 by the wiring deterioration diagnostic unit 21 in the wire harness. Node A, node B, node C, node D, and node E in FIG. 6 correspond to construction machine 10A, construction machine 10B, construction machine 10C, construction machine 10D, and construction machine 10E, respectively.

In step S21 subsequent to step S20, the wire harness wiring degradation diagnosis unit 21 detects the sensor output signal voltage abnormality S[i] transmitted from each construction machine 10 and the sensor output signal voltage abnormality detection time D[i]. , create a low-voltage abnormality diagnosis table DSL_TBL of records consisting of the fields shown in the following (9) to (16), and the data abnormality for the most recent predetermined period of the abnormality diagnosis result database performed by the wiring deterioration diagnosis unit 21 in the wire harness The following (11) to (15) are retrieved from the diagnosis record using a character string combining the following (9) and (10) as a retrieval key, and the results are applied to the corresponding fields of the table DSL_TBL.
(9) the node ID associated with the undervoltage fault;
(10) Time when the low voltage abnormality of the node ID occurred (11) Low voltage abnormality diagnosis result of the sensor 11A output signal searched by the combination of (9) and (10) above,
(12) low voltage abnormality diagnosis result of the sensor 11B output signal retrieved by the combination of (9) and (10) above;
(13) Low voltage abnormality diagnosis result of the sensor 11C output signal searched by the combination of (9) and (10) above,
(14) low voltage abnormality diagnosis result of the sensor 11D output signal retrieved by the combination of (9) and (10) above;
(15) low voltage abnormality diagnosis result of the sensor 11E output signal retrieved by the combination of (9) and (10) above;
(16) Diagnosis result of deterioration of connection in wiring harness related to low voltage abnormality.

Next, the wiring deterioration diagnostic unit 21 sorts the records of the created table DSL_TBL in ascending order of priority of “node ID” and “occurrence time”, and then sorts the result to the first of the table. A consecutive number is assigned to the field "No." starting from 1 in order from the record. Subsequently, the wiring deterioration diagnostic unit 21 in the wire harness calculates the number of node IDs excluding duplication of "node IDs" from the number of records in the table DSL_TBL, defines and sets the value as L_Node_ID_Max, and also sets the value as L_Node_ID_Max. Define and set the IDs in order as the low voltage fault node ID array L_Node_ID[L_Node_ID_Max].

FIG. 7 shows, for example, the low-voltage abnormality table created in step S21 by the wiring deterioration diagnostic unit 21 in the wire harness. Node A, node B, node C, node D, and node E in FIG. 7 correspond to construction machine 10A, construction machine 10B, construction machine 10C, construction machine 10D, and construction machine 10E, respectively.

In step S22 subsequent to step S21, the wiring deterioration diagnosis unit 21 in the wire harness determines whether or not the number of wire harness high voltage abnormalities occurring at the same time is a certain number (here, 2) or more. Specifically, the wiring deterioration diagnostic unit 21 in the wire harness first defines H_Node_ID_Index and initializes H_Node_ID_Index=1. Subsequently, the wire harness wiring degradation diagnosis unit 21 repeats the following processing from the top of the record for the high voltage abnormality diagnosis table DSH_TBL shown in FIG. 6 created in step S20 until H_Node_ID_Index>H_Node_ID_Max.

That is, the wiring deterioration diagnosis unit 21 first defines H_D_Index as the record number having the smallest record number among the records whose node ID is equal to the value of H_Node_ID[H_Node_ID_Index] in the high voltage abnormality diagnosis table DSH_TBL. Similarly, define and set the largest record number as H_D_NumBot. Subsequently, the wiring deterioration diagnostic unit 21 in the wire harness detects that the high voltage abnormality is detected in the "wire harness" field of the H_D_Index-th record from the top of the high voltage abnormality diagnosis table DSH_TBL in the sensors 11A to 11E of the same record at the same time. In a state in which a plurality of occurrences (number of occurrences at the same time) occur, if the number of occurrences at the same time is 2 or more, it is determined that "wire harness high voltage abnormality" (see step S23). ” (see step S24). Subsequently, the in-wire-harness wiring degradation diagnostic unit 21 sets H_D_Index=H_D_Index+1 and moves to the next candidate. Such processing is then repeated until H_D_Index≧H_D_NumBot. Subsequently, the wiring deterioration diagnostic unit 21 in the wire harness sets H_Node_ID_Index=H_Node_ID_Index+1 and moves to the next node ID candidate. The determination results of steps S22 to S24 are shown, for example, in the "wire harness" column in FIG.

In step S25 subsequent to step S23 or step S24, the wiring deterioration diagnostic unit 21 in the wire harness determines whether or not the number of simultaneous occurrences of the wire harness low voltage abnormality is a certain number (here, 2) or more. Specifically, the wiring deterioration diagnostic unit 21 in the wire harness first defines L_Node_ID_Index and initializes L_Node_ID_Index=1. Subsequently, the wiring deterioration diagnostic unit 21 in the wire harness repeats the following processing from the beginning of the record for the low voltage abnormality diagnostic table DSL_TBL shown in FIG. 7 created in step S21 until L_Node_ID_Index>L_Node_ID_Max.

That is, the wire harness deterioration diagnosis unit 21 first defines the smallest record number among the records whose node ID is equal to the value of L_Node_ID [L_Node_ID_Index] in the low voltage abnormality diagnosis table DSL_TBL as L_D_Index. Similarly, define and set the largest record number as L_D_NumBot. Subsequently, the in-wire-harness wiring deterioration diagnosis unit 21 checks that the "wire harness" field of the L_D_Index-th record from the top of the low-voltage abnormality diagnosis table DSL_TBL indicates that a low-voltage abnormality is detected in the sensors 11A to 11E of the same record at the same time. In a state in which a plurality of occurrences (number of occurrences at the same time) occur, if the number of occurrences at the same time is 2 or more, it is determined that "wire harness low voltage abnormality" (see step S26), otherwise "wire harness normal (see step S27). Subsequently, the wiring degradation diagnostic unit 21 in the wire harness sets L_D_Index=L_D_Index+1 and shifts to the next candidate. Such processing is then repeated until L_D_Index≧L_D_NumBot. Subsequently, the in-wire-harness wiring deterioration diagnosis unit 21 sets L_Node_ID_Index=L_Node_ID_Index+1 and moves to the next node ID candidate. The determination results of steps S25 to S27 are shown, for example, in the "wire harness" column in FIG.

In step S28 subsequent to step S26 or step S27, the wiring deterioration diagnostic unit 21 in the wire harness diagnoses the deterioration of the connection in the wire harness. Here, based on the results of steps S22 to S27, the wiring deterioration diagnosis unit 21 in the wire harness detects when at least one of "wire harness high voltage abnormality" and "wire harness high voltage abnormality" exists in a certain node ID. Then, it is diagnosed that the connection in the wire harness of the node ID has deteriorated.

In the wiring deterioration diagnosis system 1 in the wiring harness configured as described above, the controller 17 determines whether there is a high voltage abnormality or a low voltage abnormality in the sensor output signal based on the signals output from the sensors 11A to 11E. The wiring deterioration diagnostic unit 21 in the wiring harness diagnoses the deterioration of the connections 13 to 16 in the wiring harness based on at least one of the high voltage abnormality and the low voltage abnormality of the signals output from the sensors 11A to 11E. Deterioration of wiring in the harness can be easily diagnosed. Moreover, the deterioration of the connections 13 to 16 in the wire harness can be accurately diagnosed with a simple configuration because the diagnosis can be made based on the voltage abnormality of the sensor output signal without making any special design or manufacturing changes to the wire harness. be able to.

In this embodiment, the number of simultaneous occurrences of the high voltage abnormality or the low voltage abnormality is 2 or more, but the number of simultaneous occurrences may be 3 or more or 4 or more. If so, it is possible to improve the accuracy of diagnosing deterioration of connections in the wire harness. Further, in the present embodiment, the order of creation of the high voltage abnormality diagnosis table and the low voltage abnormality diagnosis table may be exchanged, and the judgment processing for determining whether the number of simultaneous occurrences of high voltage abnormality and low voltage abnormality at the same time is equal to or greater than a certain value may be exchanged. Also good.

Further, in the present embodiment, the wiring degradation diagnosis unit 21 in the wire harness further determines the wire harness based on the simultaneous occurrence frequency of at least one of the high voltage abnormality and the low voltage abnormality of the signals output from the sensors 11A to 11E. It is preferable to diagnose deterioration of internal wiring. For example, the wiring deterioration diagnostic unit 21 in the wire harness repeats at least one of the high voltage abnormality and the low voltage abnormality at a predetermined interval at a predetermined interval (referred to as the frequency of occurrence at the same time) (here, 2) or more. If so, diagnose that the wire harness has deteriorated. In this way, erroneous diagnosis due to noise or the like can be reduced.

Note that various modifications of the in-wire-harness wiring degradation diagnostic system 1 according to the present embodiment are conceivable.

[Modification 1]
For example, in Modification 1 shown in FIG. 8 , the wiring degradation diagnostic system 1 in the wire harness further includes a terminal 50 capable of communicating with the server 20 . The terminal 50 is, for example, a PC (Personal Computer) or a portable terminal owned by maintenance personnel, users, or the like. Mobile terminals include smartphones, tablet terminals, mobile phones, and PDAs (Personal Data Assistants).

Then, the server 20 transmits the deterioration diagnosis result of the wiring in the wire harness together with the node ID to the terminal 50, and notifies the maintenance personnel, the user, and the like. A maintenance person, a user, or the like can easily identify which wire connection in which wire harness of which construction machine 10 has deteriorated via the terminal 50, and can quickly replace the deteriorated one. , the stable operation of the construction machine 10 can be maintained.

[Modification 2]
In Modified Example 2 shown in FIG. 9, in construction machine 10, controller 17 is connected to sensors 11A to 11E via in-vehicle network 18A instead of signal line 18, respectively. The in-vehicle network 18A is, for example, a CAN (Controller Area Network). Accordingly, the sensors 11A to 11E output the detected results to the controller 17 via CAN.

[Modification 3]
In addition, in Modification 3 shown in FIG. 10 , the wiring deterioration diagnostic unit in the wire harness is provided in the controller 17 instead of the server 20 side. That is, as shown in FIG. 10, the controller 17 has an in-wire-harness wiring deterioration diagnosis unit 171 . In this case, the wiring degradation diagnosis unit 171 in the wire harness is based on the sensor output signal voltage abnormality S[i] and the sensor output signal voltage abnormality detection time D[i] stored in the storage device of the server 20, and according to the above-described content. Deterioration of the connections 13 to 16 in the wiring harness of the mounted construction machine 10 is diagnosed. Furthermore, the wiring deterioration diagnosis unit 171 in the wire harness periodically transmits the diagnosis result to the server 20 and stores it in the database 30 of the server 20 .

Then, the server 20 can reduce erroneous diagnosis by closely examining the received diagnosis result of the wiring deterioration diagnosis unit 171 in the wiring harness of each construction machine 10 . In addition, the server 20 transmits the results of the diagnosis made by the wiring deterioration diagnosis unit 171 in the wiring harness of each construction machine 10 to the terminal 50, and notifies maintenance personnel, users, and the like.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the invention described in the claims. Changes can be made.

1 wiring deterioration diagnosis system in wiring harness 10 construction machines 11A, 11B, 11C, 11D, 11E sensor 12P power supply line 12G ground line 13, 14, 15, 16 connection 13A, 13B, 14A, 14B, 15A, 15B, 16A, 16B Branch unit 17 Controller 18 Signal line 18A In-vehicle network 19 Communication unit 20 Server 21 Wiring degradation diagnostic unit in wire harness 30 Database 40 Network 50 Terminal 171 Wiring degradation diagnostic unit in wire harness

Claims (5)

a plurality of sensors;
a controller that receives signals output from the plurality of sensors;
a common power supply line and a common ground line for supplying power to the plurality of sensors;
a wire harness that electrically connects the plurality of sensors and the power supply line, and the plurality of sensors and the ground line, respectively;
a wiring deterioration diagnostic unit in the wiring harness that diagnoses deterioration of the wiring in the wiring harness based on at least one of high voltage abnormality and low voltage abnormality of the signals output from the plurality of sensors;
A wiring deterioration diagnostic system in a wire harness, comprising: The wiring deterioration diagnostic unit in the wire harness is a simultaneous occurrence signal indicating a state in which a plurality of high voltage anomalies or low voltage anomalies of the signals output from the plurality of sensors have occurred at the same time. 2. A wiring deterioration diagnosis system in a wire harness according to claim 1, wherein the deterioration of the wiring in the wire harness is diagnosed based on the number. The wiring deterioration diagnostic unit in the wiring harness diagnoses deterioration of the wiring in the wiring harness based on the simultaneous occurrence frequency of at least one of high voltage abnormalities and low voltage abnormalities in the signals output from the plurality of sensors. 3. The system for diagnosing deterioration of wiring in a wire harness according to claim 2. further comprising a server capable of communicating with the controller;
4. The in-wire harness wiring deterioration diagnosis system according to claim 1, wherein the in-wire harness wiring deterioration diagnosis unit is provided in the server. 4. The in-wire harness wiring deterioration diagnosis system according to claim 1, wherein the in-wire harness wiring deterioration diagnosis unit is provided in the controller.

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