A harness detection device and a detection method

Abstract

The application provides a wire harness detection device and method, which comprises a man-machine interface, a report printing device, an information comprehensive processing system, a detection circuit, an interface adaptation board 2, wherein the information comprehensive processing system is connected with the man-machine interface, the report printing device and the detection circuit respectively; M connectors 4 are arranged on the interface adaptation board 2, the positive end and the negative end of the detection circuit are connected with the connectors 4 on the interface adaptation board 2 through connecting cables 1, and the two ends of the measured wire harness 3 are connected with two connectors 4 on the interface adaptation board 2 respectively; the shells of all the connectors on the interface adaptation board 2 are connected with a power supply ground 9.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aviation, in particular to a wire harness detection device and detection method. BACKGROUND

[0002] Wire harnesses are ubiquitous in various aspects of industrial production, and they are like the nervous system of the human body, bearing the task of information transmission and energy transmission. The quality of the wire harness directly affects the efficiency of production and the reliability of the product, so quickly detecting the quality of the wire harness and accurately locating the fault are important for improving the production capacity of industry. However, due to the diversity and invisibility of wire harness faults, it is a challenge to detect the quality of the wire harness. Patent CN 105785210B detects the quality of the wire harness used in vehicles, mainly detecting intermittent open circuits at the microsecond level. It cannot check problems such as poor contact in multi-strand wire harnesses, shell short circuits, and short circuits between wire harnesses. Patent CN111308391B uses a voltage comparator to detect continuity, mainly detecting cable continuity, which is not suitable for problems such as poor contact in multi-strand wire harnesses, shell short circuits, and short circuits between wire harnesses. SUMMARY

[0003] The present application provides a wire harness detection device and detection method, which can effectively detect wire harnesses with various fault modes and accurately locate them, greatly improving the efficiency and accuracy of wire harness detection.

[0004] In a first aspect, the present application provides a wire harness detection device, which comprises a human-computer interaction interface, a report printing device, an information comprehensive processing system, a detection circuit, and an interface adapter board 2, wherein:

[0005] The information comprehensive processing system is connected with the human-computer interaction interface, the report printing device, and the detection circuit; the interface adapter board 2 is provided with M connectors 4, the positive and negative terminals of the detection circuit are connected with the connectors 4 on the interface adapter board 2 through connection cables 1, and the two ends of the measured wire harness 3 are connected with two connectors 4 on the interface adapter board 2; the housings of all the connectors on the interface adapter board 2 are connected with a power supply ground 9;

[0006] The detection circuit comprises an input-output module, connection cables 1, and N single-channel detection circuits 5, the single-channel detection circuit 5 comprises a current limiting protector, an adjustable constant current source, a first voltage acquisition module, a second voltage acquisition module, and a voltage dividing resistor;

[0007] The positive terminal of the detection circuit is connected with the negative terminal of the detection circuit through a current-limiting protector, an adjustable constant current source and a voltage dividing resistor in sequence; the negative terminal of the detection circuit is connected with one end of a first voltage acquisition module and a second voltage acquisition module respectively, the other end of the first voltage acquisition module is connected with the positive terminal of the detection circuit, and the other end of the second voltage acquisition module is connected with the output terminal of the voltage dividing resistor; the first voltage acquisition module, the second voltage acquisition module and the adjustable constant current source are connected with an input and output module;

[0008] The first voltage measurement point 6 is the intersection of the first voltage acquisition module, the output terminal of the current-limiting protector and the connecting cable 1.

[0009] The second voltage measurement point 7 is the intersection of the second voltage acquisition module, the output terminal of the voltage dividing resistor and the input terminal of the adjustable constant current source.

[0010] The third voltage measurement point 8 is the intersection of the first voltage acquisition module, the second voltage acquisition module and the input terminal of the voltage dividing resistor.

[0011] Specifically, the human-computer interaction interface transmits the received current value I1 to the information comprehensive management system, the information comprehensive management system transmits the current value to the input and output module, and then sets the excitation current I1 of the adjustable constant current source; the current-limiting protector is used for protecting the detection circuit to prevent damage to the detection circuit due to excessive current; the excitation current flows through the measured wire harness 3 and then enters the voltage dividing resistor, and finally returns to the adjustable constant current source to form a closed loop; the single-channel detection circuit 5 is provided with the first voltage measurement point 6, the second voltage measurement point 7 and the third voltage measurement point 8; the high end of the first voltage acquisition module is connected at the first voltage measurement point 6, and the low end is connected at the third voltage measurement point 8, and the measured voltage is U1; the high end of the second voltage acquisition module is connected at the second voltage measurement point 7, and the low end is connected at the third voltage measurement point 8, and the measured voltage is U2; the fault type of the measured wire harness 3 is judged according to U1 and U2.

[0012] Specifically, the human-computer interaction interface is used for completing parameter setting and detection result display, the parameter setting mainly sets the current size and detection threshold of the adjustable constant current source in the detection circuit, and the result display displays the detection situation of the final wire harness.

[0013] Specifically, the information comprehensive processing system completes the information transmission between the human-computer interaction interface and the detection circuit, and controls the report printing; the detection circuit realizes the constant current source excitation and voltage signal acquisition, and the fault information of the wire harness is characterized by the voltage signal; the interface adapter board 2 is convenient for connecting connectors 4 with different core numbers and different specifications to adapt to different forms of wire harness detection.

[0014] In a second aspect, the application provides a wiring harness detection method, which is applied to the wiring harness detection device of claim 1, the detection circuit comprises a single-channel detection circuit 5, and the method comprises the following steps:

[0015] Step 1: collecting voltage U1 by using the first voltage collection module of the wiring harness detection device and collecting voltage U2 by using the second voltage collection module;

[0016] Step 2: judging the fault type of the measured wiring harness 3 according to U1 and U2, wherein the fault type of the measured wiring harness 3 comprises normal, broken line, poor contact and short circuit with the shell.

[0017] Specifically, step 2 comprises:

[0018] If the voltage of U1 is within the range of I*R2*(1±Y) and the voltage of U2 is within the range of I*R1*(1±Y), then the measured wiring harness 3 is judged as a normal wiring harness, wherein I is the excitation current, U is the maximum output voltage capability of the adjustable constant current source, R1 is the voltage dividing resistor, R2 is the equivalent resistance of the measured wiring harness 3, Y is the detection threshold, and H is the precision of the voltage collection module;

[0019] If the voltage of U1 is within the range of U*(1±Y), then the measured wiring harness 3 is judged as a broken line;

[0020] If the voltages of U1 and U2 jump irregularly, then the measured wiring harness 3 is judged as a poor contact;

[0021] If the voltages of U1 and U2 are both less than U 短接 , then the measured wiring harness 3 is judged as a short circuit with the shell, wherein U 短接 is the voltage judgment threshold of the short circuit with the shell.

[0022] In a third aspect, the application provides a wiring harness detection method, the detection circuit comprises three single-channel detection circuits 5, the measured wiring harnesses are wiring harness a 10, wiring harness b 11 and wiring harness c 12 respectively, wiring harness a is connected to the single-channel detection a in the detection circuit, wiring harness b is connected to the single-channel detection b in the detection circuit, wiring harness c is connected to the single-channel detection c in the detection circuit, and the wiring harness detection method comprises the following steps:

[0023] Step 1: collecting the voltage Ua1 between the first voltage measurement point 6 and the third voltage measurement point 8 by using the first voltage collection module of the single-channel detection a and collecting the voltage Ua2 between the second voltage measurement point 7 and the third voltage measurement point 8 by using the second voltage collection module of the single-channel detection a;

[0024] Step 2: collect the voltage Ub1 between the first voltage measuring point 6 and the third voltage measuring point 8 by the first voltage acquisition module of the single-channel detection b; collect the voltage Ub2 between the second voltage measuring point 7 and the third voltage measuring point 8 by the second voltage acquisition module of the single-channel detection b;

[0025] Step 3: collect the voltage Uc1 between the first voltage measuring point 6 and the third voltage measuring point 8 by the first voltage acquisition module of the single-channel detection c; collect the voltage Uc2 between the second voltage measuring point 7 and the third voltage measuring point 8 by the second voltage acquisition module of the single-channel detection c;

[0026] Step 4: according to Ua1, Ua2, Ub1, Ub2, Uc1, Uc2, judge the fault type of the measured wire harness 3, wherein the fault type of the measured wire harness 3 includes normal, broken line, poor contact, short circuit with the shell, two wire harness short circuit, and three wire harness short circuit.

[0027] Specifically, step 4 includes:

[0028] If the voltages of Ua1, Ub1, Uc1 are all within the range of I*R2*(1±Y), and the voltages of Ua2, Ub2, Uc2 are within the range of I*R1*(1±Y), then the measured wire harness 3 is judged to be normal, wherein I is the excitation current, U is the maximum output voltage capability of the adjustable constant current source, R1 is the voltage dividing resistor, R2 is the equivalent resistance of the measured wire harness 3, Y is the detection threshold, and H is the precision of the voltage acquisition module;

[0029] If the voltages of Ua1, Ub1, Uc1 are within the range of U*(1±Y), then the measured wire harness 3 is judged to be a broken line;

[0030] If the voltages of Ua1, Ua2, Ub1, Ub2, Uc1, Uc2 jump irregularly, then the measured wire harness 3 is judged to be a poor contact;

[0031] If the voltages of Ua1, Ua2, Ub1, Ub2, Uc1, Uc2 are all less than U 短接 , then the measured wire harness 3 is judged to be a short circuit with the shell, wherein U 短接 is the voltage judgment threshold of the short circuit with the shell.

[0032] In summary, the technical effects are:

[0033] 1. The device and detection method designed by the application are simple and easy to understand, and are convenient for industrial implementation. The wire harness detection work can be quickly completed through the man-machine interface and report printing, and the work efficiency is improved;

[0034] 2、The application can detect multiple fault types simultaneously, including: normal, broken line, poor contact, short circuit with the shell and short circuit between the wire harness, and the covered fault types basically include the common fault types in industrial field;

[0035] 3、The detection threshold of the application is flexible and can be set, which is suitable for wire harnesses with different conductivity, different wire diameter and different length;

[0036] 4、The application adopts an adjustable constant current source, simultaneously adopts single-channel detection a, single-channel detection b and single-channel detection c, and adopts the modular design of interface adapter board, which is convenient for the expansion of the detection circuit, and thus can conveniently adapt to wire harnesses with different core numbers.

[0037] 5、The application adopts the detection method of current excitation and voltage measurement, which can realize rapid and accurate positioning of the wire harness fault. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 Overall architecture of the detection device;

[0039] Figure 2 Single-channel detection schematic;

[0040] Figure 3 Multi-wire harness detection schematic;

[0041] 1-connection cable, 2-interface adapter board, 3-wire harness under test, 4-connector, 5-single-channel detection circuit, 6-first voltage measurement point, 7-second voltage measurement point, 8-third voltage measurement point, 9-power ground, 10-wire harness a under test, 11-wire harness b under test, 12-wire harness c under test. DETAILED DESCRIPTION

[0042] Example 1

[0043] As shown in Figure 1 The application provides a wire harness detection device, which comprises a man-machine interaction interface, a report printing device, an information comprehensive processing system, a detection circuit, an interface adapter board 2, wherein:

[0044] The information comprehensive processing system is connected with the man-machine interaction interface, the report printing device and the detection circuit respectively; the interface adapter board 2 is provided with M connectors 4, the positive end and the negative end of the detection circuit are connected with the connectors 4 on the interface adapter board 2 through connection cables 1, and the two ends of the wire harness under test 3 are connected with two connectors 4 on the interface adapter board 2 respectively; the shells of all the connectors on the interface adapter board 2 are connected with the power ground 9;

[0045] The detection circuit comprises an input-output module, a connection cable 1 and N single-channel detection circuits 5, the single-channel detection circuit 5 comprises a current limiting protector, an adjustable constant current source, a first voltage acquisition module, a second voltage acquisition module and a voltage dividing resistor;

[0046] The positive end of the detection circuit is connected with the negative end of the detection circuit through a current-limiting protector, an adjustable constant current source and a voltage dividing resistor in sequence; the negative end of the detection circuit is connected with one end of a first voltage acquisition module and a second voltage acquisition module respectively, the other end of the first voltage acquisition module is connected with the positive end of the detection circuit, and the other end of the second voltage acquisition module is connected with the output end of the voltage dividing resistor; the first voltage acquisition module, the second voltage acquisition module and the adjustable constant current source are connected with an input and output module;

[0047] The first voltage measurement point 6 is the intersection of the first voltage acquisition module, the output end of the current-limiting protector and the connecting cable 1.

[0048] The second voltage measurement point 7 is the intersection of the second voltage acquisition module, the output end of the voltage dividing resistor and the input end of the adjustable constant current source.

[0049] The third voltage measurement point 8 is the intersection of the first voltage acquisition module, the second voltage acquisition module and the input end of the voltage dividing resistor.

[0050] Specifically, the working principle of the harness detection device is that the human-computer interaction interface transmits the received current value I1 to an information comprehensive management system, the information comprehensive management system transmits the current value to an input and output module, and then sets the excitation current I1 of the adjustable constant current source; the current-limiting protector is used for protecting the detection circuit and preventing the detection circuit from being damaged due to excessive current; the excitation current flows through the measured harness 3 and then enters the voltage dividing resistor, and finally returns to the adjustable constant current source, forming a closed loop; the single-channel detection circuit 5 is provided with a first voltage measurement point 6, a second voltage measurement point 7 and a third voltage measurement point 8; the high end of the first voltage acquisition module is connected at the first voltage measurement point 6, the low end is connected at the third voltage measurement point 8, and the measured voltage is U1; the high end of the second voltage acquisition module is connected at the second voltage measurement point 7, the low end is connected at the third voltage measurement point 8, and the measured voltage is U2; the fault type of the measured harness 3 is judged according to U1 and U2.

[0051] It should be noted that the measured harness 3 is a resistor with a small resistance value, and the current flowing through the measured harness 3 will form a certain voltage drop.

[0052] Specifically, the human-computer interaction interface is used for completing parameter setting and detection result display, the parameter setting mainly sets the current size and detection threshold of the adjustable constant current source in the detection circuit, and the result display displays the detection situation of the final harness, if there is no problem, it displays that the detection is completed and passed, and if there is a problem, it displays the fault type and fault positioning information.

[0053] Specifically, the report printing device is used to print the final detection result for later checking. The information comprehensive processing system completes information transmission between the man-machine interface and the detection circuit, and controls report printing. The detection circuit realizes constant current source excitation and voltage signal acquisition, and the fault information of the wire harness is represented by the voltage signal. The interface adapter board 2 is convenient for connecting connectors 4 of different core numbers and different specifications to adapt to different forms of wire harness detection.

[0054] Embodiment two

[0055] As shown in Figure 2 , the embodiment of the application takes a single-channel detection circuit 5 as an example for description.

[0056] The application provides a wire harness detection method, which is applied to the wire harness detection device, the detection circuit includes a single-channel detection circuit 5, and the method comprises the following steps:

[0057] Step 1: collecting voltage U1 by using the first voltage acquisition module of the wire harness detection device, and collecting voltage U2 by using the second voltage acquisition module;

[0058] Step 2: judging the fault type of the measured wire harness 3 according to U1 and U2, wherein the fault type of the measured wire harness 3 includes normal, broken line, poor contact, and short circuit with the shell.

[0059] Specifically, step 2 comprises:

[0060] If the voltage of U1 is within the range of I*R2*(1±Y), and the voltage of U2 is within the range of I*R1*(1±Y), then the measured wire harness 3 is judged to be a normal wire harness, wherein I is the excitation current, U is the maximum output voltage capability of the adjustable constant current source, R1 is the voltage dividing resistor, R2 is the equivalent resistance of the measured wire harness 3, Y is the detection threshold, and H is the precision of the voltage acquisition module.

[0061] If the voltage of U1 is within the range of U*(1±Y), then the measured wire harness 3 is judged to be a broken line.

[0062] If the voltages of U1 and U2 jump irregularly, then the measured wire harness 3 is judged to be a poor contact.

[0063] If the voltages of U1 and U2 are both less than U 短接 , then the measured wire harness 3 is judged to be a short circuit with the shell, wherein U 短接 is the voltage judgment threshold of the short circuit with the shell.

[0064] For example, the excitation current I1 is 1 mA, the maximum output voltage capability of the adjustable constant current source is 15 V, the voltage dividing resistor is 1 KΩ, the equivalent resistance of the measured wire harness 3 is 1 Ω, the detection threshold is 1%, and the precision of the voltage acquisition module is 0.1%.

[0065] a) When the tested wiring harness 3 is normal, the theoretical voltage of U1 is 1mV and the theoretical voltage of U2 is 1V. Since the voltage acquisition module has certain accuracy limitations, it is impossible to measure the theoretical voltage. Therefore, it is necessary to judge based on the set detection threshold. When the voltage of U1 is within the range of 1mV*(1±1%) and the voltage of U2 is within the range of 1V*(1±1%), it can be judged that the tested wiring harness 3 is normal.

[0066] b) When the tested wiring harness 3 is broken, the theoretical voltage of U1 is 15V and the theoretical voltage of U2 is 0V. When the voltage of U1 is within the range of 15V*(1±1%), it can be determined that the tested wiring harness 3 is broken.

[0067] c) When the tested wiring harness 3 has poor contact, the theoretical voltages of U1 and U2 are related to the state of the tested wiring harness 3 and are changing voltage values. When the voltages of U1 and U2 fluctuate irregularly, it can be determined that the tested wiring harness 3 has poor contact.

[0068] d) When the tested wire harness 3 is short-circuited to the housing, since the connector housing is connected to the power ground 9 of the detection circuit, the theoretical voltage of U1 is close to 0V, and the theoretical voltage of U2 is close to 0V. When the voltages of U1 and U2 are both less than 50mV (this value can be adjusted according to the actual cable length), it can be determined that the tested wire harness 3 is short-circuited to the housing.

[0069] Example 3

[0070] like Figure 3 As shown, this embodiment of the application uses a detection circuit including three single-channel detection circuits 5 as an example for illustration.

[0071] This application provides a wire harness detection method, which is applied to the aforementioned wire harness detection device. The detection circuit includes three single-channel detection circuits 5, and the wire harnesses to be tested are wire harness a10, wire harness b11, and wire harness c12. Wire harness a is connected to single-channel detection a in the detection circuit, wire harness b is connected to single-channel detection b in the detection circuit, and wire harness c is connected to single-channel detection c in the detection circuit. The method includes:

[0072] Step 1: Use the first voltage acquisition module of single-channel detection a to acquire the voltage Ua1 between the first voltage measurement point 6 and the third voltage measurement point 8; use the second voltage acquisition module of single-channel detection a to acquire the voltage Ua2 between the second voltage measurement point 7 and the third voltage measurement point 8;

[0073] Step 2: Use the first voltage acquisition module of single-channel detection b to acquire the voltage Ub1 between the first voltage measurement point 6 and the third voltage measurement point 8; use the second voltage acquisition module of single-channel detection b to acquire the voltage Ub2 between the second voltage measurement point 7 and the third voltage measurement point 8;

[0074] Step 3: Collect the voltage Uc1 between the first voltage measurement point 6 and the third voltage measurement point 8 by the first voltage collection module of the single-path detection c; collect the voltage Uc2 between the second voltage measurement point 7 and the third voltage measurement point 8 by the second voltage collection module of the single-path detection c;

[0075] Step 4: Determine the fault type of the measured wire harness 3 according to Ua1, Ua2, Ub1, Ub2, Uc1, Uc2, wherein the fault type of the measured wire harness 3 includes normal, broken wire, poor contact, short-circuit with the shell, short-circuit of two wire harnesses, short-circuit of three wire harnesses.

[0076] Specifically, step 4 includes:

[0077] If the voltages of Ua1, Ub1, Uc1 are all within the range of I*R2*(1±Y), and the voltages of Ua2, Ub2, Uc2 are within the range of I*R1*(1±Y), then the measured wire harness 3 is determined to be normal, wherein I is the excitation current, U is the maximum output voltage capability of the adjustable constant current source, R1 is the voltage dividing resistor, R2 is the equivalent resistance of the measured wire harness 3, Y is the detection threshold, and H is the precision of the voltage collection module.

[0078] If the voltages of Ua1, Ub1, Uc1 are within the range of U*(1±Y), then the measured wire harness 3 is determined to be broken wire.

[0079] If the voltages of Ua1, Ua2, Ub1, Ub2, Uc1, Uc2 jump irregularly, then the measured wire harness 3 is determined to be poor contact.

[0080] If the voltages of Ua1, Ua2, Ub1, Ub2, Uc1, Uc2 are all less than U 短接 , then the measured wire harness 3 is determined to be short-circuit with the shell, wherein U 短接 is the voltage determination threshold for short-circuit with the shell.

[0081] Suppose the maximum output voltage of the constant current source in the single-path detection a, the single-path detection b, and the single-path detection c is 15V, the excitation current Ia of the single-path detection a is 1mA, the excitation current Ib of the single-path detection b is 1.5mA, the excitation current Ic of the single-path detection c is 2.5mA, the voltage dividing resistor in the single-path detection a, the single-path detection b, and the single-path detection c is 1KΩ, the detection threshold is 1%, and the precision of the voltage collection module is 0.1%.

[0082] a) When the measured wire bundle 10, the measured wire bundle 11 and the measured wire bundle 12 are all normal, the theoretical voltage of Ua1 is 1 mV, the theoretical voltage of Ua2 is 1 V, the theoretical voltage of Ub1 is 1.5 mV, the theoretical voltage of Ub2 is 1.5 V, the theoretical voltage of Uc1 is 2.5 mV, and the theoretical voltage of Uc2 is 2.5 V. Since the voltage acquisition module has certain precision limit, it is impossible to measure the theoretical voltage, and therefore it is necessary to judge through the set detection threshold. Therefore, when the voltage of Ua1 is within the range of 1 mV*(1±1%) and the voltage of Ua2 is within the range of 1 V*(1±1%), it can be judged that the measured wire bundle 10 is normal; when the voltage of Ub1 is within the range of 1.5 mV*(1±1%) and the voltage of Ub2 is within the range of 1.5 V*(1±1%), it can be judged that the measured wire bundle 11 is normal; and when the voltage of Uc1 is within the range of 2.5 mV*(1±1%) and the voltage of Uc2 is within the range of 2.5 V*(1±1%), it can be judged that the measured wire bundle 12 is normal.

[0083] b) Assuming that the measured wire bundle 11 has a broken wire, and the measured wire bundle 10 and the measured wire bundle 12 are normal, the theoretical voltage of Ub1 is 15 V, and the theoretical voltage of Ub2 is 0 V. When the voltage of Ub1 is within the range of 15 V*(1±1%), it can be judged that the measured wire bundle 11 has a broken wire, and the voltages of Ua1, Ua2, Uc1 and Uc2 refer to the values in the previous step, so that the fault can be quickly located to the measured wire bundle 11. The cases of two broken wires or three broken wires are similar.

[0084] c) Assuming that the measured wire bundle 10 has a poor contact, and the measured wire bundle 11 and the measured wire bundle 12 are normal, the theoretical voltages of Ua1 and Ua2 are related to the state of the measured wire bundle 10, and are variable voltage values. When the voltages of Ua1 and Ua2 jump irregularly, it can be judged that the measured wire bundle 10 has a poor contact, so that the fault can be quickly located to the faulty wire bundle among the three wire bundles. The cases of two wire bundles having a poor contact or three wire bundles all having a poor contact are similar.

[0085] d) Assuming that the measured wire bundle 12 is short-circuited to the shell, and the measured wire bundle 10 and the measured wire bundle 11 are normal, the theoretical voltage of Uc1 is close to 0 V, and the theoretical voltage of Uc2 is close to 0 V. When the voltages of Uc1 and Uc2 are both less than 50 mV (this value can be adjusted according to the actual cable length), it can be judged that the measured wire bundle 12 is short-circuited to the shell, so that the fault can be quickly located to the faulty wire bundle among the three wire bundles. The cases of two wire bundles being short-circuited to the shell or three wire bundles all being short-circuited to the shell are similar.

[0086] e) In the case of a short circuit between two wire harnesses, assuming that the protective layer of the tested wire harness 10 and 11 is damaged, causing a short circuit, and the tested wire harness 12 is normal, according to the series-parallel relationship, since the resistance of the wire itself is small and can be ignored compared with the voltage divider resistor, the total current flowing through single-channel detector a and single-channel detector b is (1+1.5)mA=2.5mA. The equivalent resistance of the voltage divider resistors of single-channel detector a and single-channel detector b in parallel is 500Ω. Therefore, the theoretical voltage value of Ua2 and Ub2 is 1.25V. When the voltage of Ua2 and Ub2 is within the range of 1.25V*(1±1%), it can be determined that the tested wire harness 10 and 11 are short-circuited, thus achieving rapid fault location. Similarly, when the tested wiring harness 10 is shorted to the tested wiring harness 12, and the tested wiring harness 11 is normal, the theoretical voltage values ​​of Ua2 and Uc2 are 1.75V; when the tested wiring harness 11 is shorted to the tested wiring harness 12, and the tested wiring harness 10 is normal, the theoretical voltage values ​​of Ub2 and Uc2 are 2V. Therefore, fault location can be quickly determined using the voltage values ​​of Ua2, Ub2, and Uc2.

[0087] f) The situation where three wire harnesses are shorted together is similar to the previous situation. The theoretical voltage values ​​of Ua2, Ub2 and Uc2 are all 1.67V. Since the voltage values ​​corresponding to different fault types are different, the fault location of the wire harness can be quickly achieved.

[0088] Technical effects:

[0089] 1. The device and detection method designed in this invention are simple and easy to understand, facilitating industrial implementation. Through a human-machine interface and report printing, wire harness detection can be completed quickly, improving work efficiency.

[0090] 2. This invention can detect multiple fault types simultaneously, including: normal, broken wire, poor contact, short circuit to the casing, and short circuit between wire harnesses. The fault types covered basically include common fault types in industrial sites.

[0091] 3. The detection threshold of this invention is flexibly set and is applicable to wire harnesses with different conductivity, wire diameter and length.

[0092] 4. This invention uses an adjustable constant current source and a modular design with single-channel detection a, single-channel detection b, and single-channel detection c, as well as an interface adapter board. This facilitates the expansion of the detection circuit and allows for easy adaptation to wire harnesses with different core counts.

[0093] 5. This invention uses a detection method of current excitation and voltage measurement, which can achieve rapid and accurate location of wire harness faults.

Claims

1. A wiring harness detection detection device characterized by, The wire harness detection device comprises a man-machine interface, a report printing device, an information comprehensive processing system, a detection circuit, and an interface adapter board (2), wherein: The information comprehensive processing system is connected with the man-machine interface, the report printing device, and the detection circuit; M connectors (4) are arranged on the interface adapter board (2), the positive end and the negative end of the detection circuit are connected with the connectors (4) on the interface adapter board (2) through connecting cables (1), and the two ends of the measured wire harness (3) are connected with two connectors (4) on the interface adapter board (2); the shells of all the connectors on the interface adapter board (2) are connected with a power supply ground (9); The detection circuit comprises an input-output module, the connecting cables (1), and N single-channel detection circuits (5), the single-channel detection circuit (5) comprises a current-limiting protector, an adjustable constant current source, a first voltage acquisition module, a second voltage acquisition module, and a voltage dividing resistor; The positive end of the detection circuit is connected with the negative end of the detection circuit through the current-limiting protector, the adjustable constant current source, and the voltage dividing resistor in sequence; the negative end of the detection circuit is connected with one end of the first voltage acquisition module and the second voltage acquisition module, the other end of the first voltage acquisition module is connected with the positive end of the detection circuit, and the other end of the second voltage acquisition module is connected with the output end of the voltage dividing resistor; the first voltage acquisition module, the second voltage acquisition module, and the adjustable constant current source are connected with the input-output module; The first voltage measurement point (6) is the intersection of the first voltage acquisition module, the output end of the current-limiting protector, and the connecting cable (1); The second voltage measurement point (7) is the intersection of the second voltage acquisition module, the output end of the voltage dividing resistor, and the input end of the adjustable constant current source; The third voltage measurement point (8) is the intersection of the first voltage acquisition module, the second voltage acquisition module, and the input end of the voltage dividing resistor.

2. The wiring harness detection apparatus according to claim 1, characterized by The man-machine interface transmits the received current value I1 to the information comprehensive management system, the information comprehensive management system transmits the current value to the input-output module, and then sets the excitation current I1 of the adjustable constant current source; the current-limiting protector is used for protecting the detection circuit and preventing the detection circuit from being damaged due to excessive current; after the excitation current flows through the measured wire harness (3), the excitation current enters the voltage dividing resistor and finally returns to the adjustable constant current source, forming a closed loop; the single-channel detection circuit (5) is provided with the first voltage measurement point (6), the second voltage measurement point (7), and the third voltage measurement point (8); the high end of the first voltage acquisition module is connected at the first voltage measurement point (6), the low end is connected at the third voltage measurement point (8), and the measured voltage is U1; The high end of the second voltage acquisition module is connected at the second voltage measurement point (7), the low end is connected at the third voltage measurement point (8), and the measured voltage is U2; the fault type of the measured wire harness (3) is judged according to U1 and U2.

3. The wiring harness detection apparatus according to claim 1, characterized by The man-machine interface is used for completing parameter setting and detection result display, the parameter setting mainly sets the current size and the detection threshold of the adjustable constant current source in the detection circuit, and the result display displays the detection situation of the final wire harness.

4. The wiring harness detection apparatus according to claim 1, characterized by The information comprehensive processing system completes information transmission between man-machine interface and detection circuit, and controls report printing; the detection circuit realizes constant current source excitation and voltage signal acquisition, and the fault information of the wire harness is represented by voltage signal. The interface adapter board (2) is convenient for connecting connectors (4) with different core numbers and different specifications to adapt to different forms of wire harness detection.

5. A harness detection detection method characterized by, The method is applied to the wire harness detection device as claimed in claim 1, the detection circuit comprises a single-channel detection circuit (5), and the method comprises the following steps: Step 1: collecting voltage U1 by using a first voltage acquisition module of the wire harness detection device and collecting voltage U2 by using a second voltage acquisition module; Step 2: judging the fault type of the measured wire harness (3) according to U1 and U2, wherein the fault type of the measured wire harness (3) comprises normal, broken wire, poor contact and short circuit with the shell.

6. The wire harness detection method according to claim 5, characterized by, Step 2 comprises: if the voltage of U1 is within the range of I*R2*(1±Y) and the voltage of U2 is within the range of I*R1*(1±Y), then the measured wire harness (3) is judged as a normal wire harness, wherein I is an excitation current, U is the maximum output voltage capability of an adjustable constant current source, R1 is a voltage dividing resistor, R2 is the equivalent resistance of the measured wire harness (3), Y is a detection threshold, and H is the precision of the voltage acquisition module; if the voltage of U1 is within the range of U*(1±Y), then the measured wire harness (3) is judged as a broken wire; if the voltages of U1 and U2 jump irregularly, then the measured wire harness (3) is judged as poor contact; If the voltages of U1 and U2 are both less than U 短接 , the measured wire harness (3) is determined to be short-circuited with the housing, where U 短接 is a voltage determination threshold for short-circuiting with the housing.

7. A harness detection detection method characterized by, The method is realized by using the wire harness detection device of any one of claims 1 to 6, the detection circuit comprises three single-channel detection circuits (5), the measured wire harnesses are wire harness a (10), wire harness b (11) and wire harness c (12), wire harness a is connected to single-channel detection a in the detection circuit, wire harness b is connected to single-channel detection b in the detection circuit, wire harness c is connected to single-channel detection c in the detection circuit, and the wire harness detection method comprises the following steps: Step 1: collecting voltage Ua1 between the first voltage measurement point (6) and the third voltage measurement point (8) by using the first voltage acquisition module of single-channel detection a and collecting voltage Ua2 between the second voltage measurement point (7) and the third voltage measurement point (8) by using the second voltage acquisition module of single-channel detection a; Step 2: collecting voltage Ub1 between the first voltage measurement point (6) and the third voltage measurement point (8) by using the first voltage acquisition module of single-channel detection b and collecting voltage Ub2 between the second voltage measurement point (7) and the third voltage measurement point (8) by using the second voltage acquisition module of single-channel detection b; Step 3: collecting voltage Uc1 between the first voltage measurement point (6) and the third voltage measurement point (8) by using the first voltage acquisition module of single-channel detection c and collecting voltage Uc2 between the second voltage measurement point (7) and the third voltage measurement point (8) by using the second voltage acquisition module of single-channel detection c; Step 4: judging the fault type of the measured wire harness (3) according to Ua1, Ua2, Ub1, Ub2, Uc1, Uc2, wherein the fault type of the measured wire harness (3) includes normal, broken wire, poor contact, short to the shell, two wire harness short, three wire harness short.

8. The wire harness detection method according to claim 7, characterized by, Step 4 includes: If the voltages of Ua1, Ub1, Uc1 are all within the range of I*R2*(1±Y), and the voltages of Ua2, Ub2, Uc2 are within the range of I*R1*(1±Y), then the measured wire harness (3) is judged to be normal, wherein I is the excitation current, U is the maximum output voltage capability of the adjustable constant current source, R1 is the voltage dividing resistor, R2 is the equivalent resistance of the measured wire harness (3), Y is the detection threshold, and H is the precision of the voltage acquisition module; If the voltages of Ua1, Ub1, Uc1 are within the range of U*(1±Y), then the measured wire harness (3) is judged to be broken wire; If the voltages of Ua1, Ua2, Ub1, Ub2, Uc1, Uc2 jump irregularly, then the measured wire harness (3) is judged to be poor contact; If the voltages of Ua1, Ua2, Ub1, Ub2, Uc1, Uc2 are all less than U 短接 , then the measured wire harness (3) is determined to be short-circuited with the shell, wherein U 短接 is the voltage determination threshold for short-circuit with the shell.

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