Automated detection system and method for electrical failure of vehicle harness based on program-controlled power supply

Abstract

The application discloses a kind of based on program-controlled power supply's whole vehicle wire harness electrical failure automation detection system and detection method, belong to wire harness detection technical field.The system includes controller processing unit, direct current program-controlled power supply, multiplex switch, measuring instrument unit and general standard plug adapter.Through controller processing unit coordination each component work, utilize direct current program-controlled power supply simulation vehicle power supply static output and dynamic load working condition, and in combination with multiplex switch realizes the dynamic switching of test resource, cooperate measuring instrument unit gathers electrical parameter.The application is connected with the physical connection of the wire harness to be measured by general standard plug adapter, aims at solving the problem of single function, low degree of automation and difficult to simulate real working condition in prior art.The system not only improves detection efficiency and automation level, but also strengthens the detection capability of hidden fault such as load voltage drop, ensures the reliability of electrical performance of whole vehicle wire harness under complex configuration.

Description

Technical Field

[0001] This invention belongs to the field of automotive manufacturing testing equipment technology, and in particular relates to an automated detection system and method for electrical failures of vehicle wiring harnesses based on a programmable power supply. Background Technology

[0002] With the rapid development of electric commercial vehicle technology, manufacturers have generally adopted highly modular and platform-based design concepts to meet diverse needs such as urban logistics, intercity transportation, and special operations. This design trend has resulted in a vast array of optional configuration combinations for vehicle power battery capacity, drive motor power, onboard electronic and electrical architecture, and upper structure functional modules. As the "nervous system" of a car, the electrical performance of the vehicle's wiring harness directly affects vehicle safety and the realization of various functions. However, in the process of complex configuration iterations, the testing of the wiring harness system is often neglected, resulting in insufficient test coverage and making it difficult to ensure that the wiring harness system under every configuration combination can meet stringent electrical safety requirements.

[0003] Traditional wiring harness testing methods typically only perform simple static continuity tests, failing to provide a comprehensive evaluation of the wiring harness under simulated real-world operating conditions. On one hand, existing testing methods heavily rely on manual point-by-point measurements using multimeters, megohmmeters, and other equipment, resulting in low automation, inefficiency, and a high risk of missed or incorrect detections. Furthermore, they struggle to generate structured data for easy quality traceability. On the other hand, current technologies lack effective controlled excitation sources and dynamic switching logic, making it difficult to simulate real-world power fluctuations and high-current loads in vehicles. This renders them highly insensitive to latent electrical failures such as loose connections, excessive contact resistance, or insufficient wire diameter. Therefore, developing a highly automated wiring harness testing system capable of simulating load conditions through programmable control has become a pressing technical challenge for the industry. Summary of the Invention

[0004] To address the problems of limited testing functions, low automation, and insufficient detection rate of latent faults such as load voltage drop in existing wiring harness testing technologies, this invention provides an automated detection system and method for electrical failures of vehicle wiring harnesses based on a programmable power supply.

[0005] This invention is implemented as follows: an automated detection system for electrical failures of vehicle wiring harnesses based on a programmable power supply. The system comprises a controller processing unit, a DC programmable power supply, a multiplexer, a measuring instrument unit, and a universal standard connector adapter. The controller processing unit executes the detection program, coordinates the control system's operation, and determines failures. The DC programmable power supply is connected to the controller processing unit and outputs controlled voltage and current according to instructions to simulate vehicle power supply conditions. The multiplexer is connected to both the DC programmable power supply and the measuring instrument unit, and switches test paths under the control of the controller processing unit. The measuring instrument unit collects electrical parameters of the wiring harness. The universal standard connector adapter provides the physical interface between the multiplexer and the vehicle wiring harness under test.

[0006] In the above technical solution, preferably, the measuring instrument unit includes a digital multimeter unit, an insulation resistance testing unit, and a withstand voltage testing unit.

[0007] In the above technical solution, preferably, the direct current controlled power supply has the function of adjustable output voltage and current, which is used to provide excitation for the test circuit and simulate static output conditions or dynamic load conditions.

[0008] By integrating a digital multimeter and insulation and withstand voltage testing units, the system can achieve comprehensive coverage from basic continuity to high-voltage insulation performance on a single hardware platform, effectively solving the drawbacks of traditional methods that are limited in function and require frequent instrument replacement. At the same time, by utilizing a precisely adjustable DC flow control power supply, it not only provides basic excitation but also enhances the system's simulation capability for power fluctuations in actual operation through in-depth simulation of static and dynamic load conditions. This enables the accurate capture of latent failure modes such as abnormal contact resistance or insufficient load capacity, significantly improving the reliability and scientific rigor of harness failure determination in complex electrical control environments.

[0009] This invention also proposes an automated detection method for electrical failures of vehicle wiring harnesses based on the above system, characterized by comprising the following steps: S1. Load the test cases and connect the wiring harness to be tested; S2. Automated static electrical parameter testing: Control the multiplexer to switch the test circuit, obtain the conduction characteristics, insulation performance or withstand voltage performance parameters of the wire harness under test through the measuring instrument unit, and compare them with the preset threshold to make a judgment; S3. Automated dynamic load voltage drop test: Control the multiplexer to connect the DC dynamic control power supply to the power circuit of the wire harness under test and output the working current. Under stable load conditions, obtain the voltage drop parameters of the power circuit and evaluate the load capacity of the power circuit based on the voltage drop parameters. S4. Comprehensive Judgment: Integrate the test data from each step and output the judgment result.

[0010] In the above technical solution, preferably, the continuity characteristic test in step S2 includes: measuring the continuity resistance value between two terminals designed to be connected; if the continuity resistance value exceeds a preset threshold or is infinite, it is determined to be a loose connection or an open circuit.

[0011] In the above technical solution, preferably, the insulation performance test in step S2 includes: connecting the high voltage terminal of the measuring instrument unit to the conductor under test, grounding the remaining conductors and shielding layer, applying a test voltage and reading the insulation resistance value.

[0012] In the above technical solution, preferably, the withstand voltage performance test in step S2 includes: connecting the measuring instrument unit between the circuit under test and ground, applying a preset high voltage and monitoring the leakage current.

[0013] In the above technical solution, preferably, step S3 specifically includes: The rated operating current is output to the power circuit through the DC-controlled power supply; the voltage value at the far end of the power circuit is measured through the measuring instrument unit; the difference between the output voltage of the DC-controlled power supply and the voltage value at the far end is calculated to obtain the voltage drop parameter.

[0014] In the above technical solution, preferably, the power circuit in step S3 includes a grounding wire circuit or a motor power supply wire circuit; if the voltage drop parameter exceeds a preset threshold, it is determined that there is excessive contact resistance or insufficient wire diameter.

[0015] In the above technical solution, preferably, in step S4, if the determination result is unqualified, failure information is output. The failure information includes at least one of the following: failure connector code, pin number, failure type, measured value, and standard value.

[0016] In summary, this automated testing method achieves efficient and comprehensive assessment of electrical failures in vehicle wiring harnesses by constructing standardized test sequences. By organically combining static parameter testing with dynamic load-bearing voltage drop analysis, this method not only rapidly completes basic performance evaluations such as continuity, insulation, and withstand voltage, but also accurately captures latent failure modes such as loose connections and insufficient load capacity, which are difficult to detect with traditional static testing, using the core dynamic load-bearing steps. During execution, this method relies on the rapid switching logic of multiplexed switches, significantly improving test coverage and testing efficiency, completely solving the inefficiency and missed detection problems caused by manual point-by-point measurement. Furthermore, through the precise structured output of non-conforming failure information, this method provides scientific data support for subsequent failure localization and quality improvement, significantly enhancing the traceability of the wiring harness production process and the reliability of product delivery. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the detection system proposed in Embodiment 1 of the present invention; Figure 2 This is a schematic flowchart of the detection method proposed in Embodiment 2 of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] This invention provides an automated detection system and method for electrical failures of vehicle wiring harnesses based on a programmable power supply. To further illustrate the structure of this invention, a detailed description is provided below in conjunction with the accompanying drawings: Example 1 This embodiment provides an automated detection system for electrical failures of vehicle wiring harnesses based on a programmable power supply. Please refer to [link / reference]. Figure 1 The system includes a controller processing unit, a DC current controlled power supply, a multiplexer, a measuring instrument unit, and a universal standard connector. The controller processing unit, as the core of the system, executes test programs, coordinates the operation of various system components, collects data, and performs failure determination. Specifically, the controller processing unit is implemented using an industrial control computer or an embedded processor, and it has a pre-installed high-speed bus interface for establishing real-time communication links with the power supply and measuring instruments, ensuring synchronization between command issuance and data feedback. The DC current controlled power supply is connected to the controller processing unit, receives its commands, and outputs precisely adjustable voltage and current to provide excitation for the test circuit. This DC current controlled power supply can simulate not only the static output of a vehicle's power supply but also dynamic load conditions to correspond to power fluctuations and load current changes in actual vehicle operation.

[0020] The multiplexer is connected to the direct current controlled power supply and measuring instrument unit, and has multiple independently programmable switching channels. The common terminal of the multiplexer is connected to the controlled power supply and various measuring instruments, while the other terminal is connected to the wiring harness of the vehicle under test via an adapter interface. Under the command of the controller processing unit, this switch module can dynamically switch between different test resources and precisely control any terminal of the wiring harness under test. To ensure safety under high current load testing, the multiplexer is composed of a high-lifespan, low-contact-resistance power relay array, and each channel has electrical isolation to prevent crosstalk or breakdown during high-voltage testing.

[0021] The measuring instrument unit is used to collect the electrical parameters of the wiring harness, specifically including a high-precision digital multimeter unit, an insulation resistance testing unit, and a DC / AC withstand voltage testing unit. The digital multimeter unit measures basic parameters such as resistance, voltage, and current. A universal standard connector adapter serves as a standard wiring harness connector fixture. One end connects to the multiplexer matrix, and the other end provides a physical interface compatible with all connectors of the wiring harness in the vehicle under test, ensuring physical compatibility between the testing system and wiring harnesses of different vehicle configurations. The connector adapter employs a modular adapter board structure, allowing for quick replacement of the adapter module according to the connector type of the wiring harness under test, thereby achieving platform-based compatible testing of wiring harnesses for various vehicle types, such as urban logistics vehicles and special-purpose vehicles.

[0022] In addition, the controller processing unit runs test execution software, which is configured with test procedures, judgment thresholds, and report templates for automated control of the entire test sequence. The test execution software has a graphical user interface, supports pre-setting pass / fail criteria for different harness levels through configuration files, and displays the physical quantity curves of each detection node in real time during the test. After startup, the system automatically loads the corresponding test cases by scanning the identifier of the harness under test (such as a barcode or QR code). Subsequently, the operator physically connects all interfaces of the harness under test to a universal standard connector.

[0023] After the physical connection is completed, the system enters the automated testing phase. First, automated continuity and resistance tests are performed. The controller processing unit controls the multiplexer, and the resistance setting of the digital multimeter is sequentially connected between all the terminals designed to be conductive, measuring the actual continuity resistance. The measured value is compared with a preset threshold in the test case. If the resistance value exceeds the limit or is infinite, the system automatically determines that the node has a loose connection or open circuit fault. To eliminate the influence of the multiplexer and adapter cable's own resistance on measurement accuracy, the system performs a no-load zeroing procedure before measurement, automatically subtracting the system bias resistance of the test circuit using pre-stored calibration parameters.

[0024] Subsequently, an automated insulation resistance test is carried out. For each conductor to be tested, the system controls the switch matrix to connect the high-voltage terminal of the insulation resistance tester to this conductor, and at the same time, uniformly ground all the other conductors and the shielding layer through the switch matrix. By applying a specified test voltage and reading the insulation resistance value, it is compared with the preset threshold to determine whether the insulation performance is qualified. Immediately afterwards, an automated withstand voltage test is executed. The control switch matrix connects the withstand voltage tester between the tested circuit and the ground, applies a specified high voltage and maintains it for a specified time, and the leakage current is monitored in real time during this period. If the leakage current exceeds the preset threshold, it is determined that the withstand voltage breakdown fails. When performing high-voltage tests (insulation and withstand voltage), the controller processing unit will pre-detect the closed state of all switch channels to ensure that the non-test circuit is completely cut off to protect the low-voltage electronic components from being damaged by high voltage.

[0025] The core step of this embodiment is the dynamic load-carrying and voltage drop test, which is mainly aimed at key power circuits such as grounding wires and motor power supply wires. During the test, first control the switch matrix to access the digital multimeter to form a circuit, and then instruct the DC programmable power supply to output the rated working current corresponding to this circuit. After the load current reaches a stable state, the system switches the multiplexer switch and uses the digital multimeter to measure the voltage value at the far end of this circuit. By calculating the difference between the power supply output voltage and the voltage measured at the far end, the circuit voltage drop is obtained, and it is compared with the preset threshold. An excessive voltage drop indicates that there are quality problems such as too high contact resistance or insufficient wire diameter in this power circuit. This test can effectively identify loose connection faults that are difficult to detect by static conduction tests, and by simulating real large-current working conditions, it forces the exposure of abnormal electrothermal characteristics of the connection point under the load state.

[0026] Finally, the system enters the comprehensive judgment and report generation stage. The controller processing unit integrates all the above test data and automatically determines that the final result of the entire wire harness is "qualified" or "unqualified". For the detected unqualified items, the system will accurately output the failure information, including the failure connector code, pin number, failure type (such as short circuit, open circuit, poor insulation, insufficient load capacity, etc.), measured value, and standard value. Finally, the system automatically generates a structured test report for electronic storage, and supports printing qualified or unqualified labels to achieve full life-cycle traceability of the test data and quality traceability analysis. In addition, the system has an automatic data upload interface, which can synchronize the test report to the factory's MES system to provide data support for subsequent wire harness process improvement and production trend analysis.

[0027] Embodiment 2 This embodiment provides an automated detection method for electrical failures of a vehicle wire harness. This method is realized based on the aforementioned detection system, aiming to solve the problems of insufficient coverage of wire harness testing caused by configuration redundancy in electric commercial vehicles and low efficiency of traditional manual testing. This method includes: S1. Load test cases and connect the wiring harness under test. In practice, the system first scans the identification code (such as a barcode or QR code) on the wiring harness under test using a scanner, retrieves the wiring diagram, terminal definitions, and test parameters for the corresponding vehicle model from the database, and loads the corresponding test cases accordingly. Following the interface wizard provided by the test cases, the operator connects all physical connectors of the wiring harness under test to the universal standard adapter one-to-one, establishing an electrical path. During the test case loading phase, the system automatically performs a self-check of the current hardware environment, confirming that all channels of the multiplexer are in their initial reset state and verifying the self-maintenance parameters of the DC flow control power supply to ensure hardware safety during subsequent high-current tests.

[0028] S2. Automated static electrical parameter testing involves controlling a multiplexer to switch test circuits and acquiring the continuity, insulation, or withstand voltage parameters of the wire harness under test through a measuring instrument unit. These parameters are then compared with preset thresholds for judgment. This step utilizes switch matrix switching commands issued by the controller processing unit to sequentially traverse all preset test circuits with a millisecond-level response speed, thereby eliminating the efficiency bottleneck and risk of missed detection caused by manual point-by-point measurement. The continuity characteristic test includes measuring the continuity resistance between two terminals designed to be conductive. The system connects a high-precision digital multimeter to the target circuit via a multiplexer. If the measured continuity resistance exceeds a preset threshold (e.g., exceeds a set ohm value) or is infinite, the system automatically determines that the circuit has a "loose connection" or "open circuit" fault.

[0029] To improve the reliability of continuity testing, the system initiates a secondary retest when resistance exceeds limits. This is achieved by slightly adjusting the contact pressure of the multiplexer or increasing the measurement sampling frequency to eliminate false positives caused by transient environmental interference. Furthermore, for multi-pin composite connectors, the system employs a matrix scanning algorithm. This not only verifies point-to-point continuity but also scans the resistance between non-designed continuity points to detect potential short circuits or misaligned crimping defects within the wiring harness. Through rapid polling of these static parameters, the system can eliminate fundamental electrical assembly errors before dynamic loading.

[0030] After completing the basic continuity test, step S2 further performs insulation and withstand voltage tests. The insulation test involves controlling a multiplexer to connect the high-voltage terminal of the measuring instrument unit to the conductor under test, and grounding all other conductors and shielding layers through a switch matrix. A specified test voltage is then applied, and the insulation resistance value is read. To ensure the comprehensiveness of the insulation test, the system automatically exhaustively searches all electrical isolation circuits using an algorithm, grouping them for high-voltage excitation to detect weak leakage paths caused by compression or wear within the wiring harness. The subsequent withstand voltage test involves connecting the withstand voltage tester between the circuit under test and ground, applying a preset high voltage for a specified time, and monitoring the leakage current in the circuit in real time. If the detected leakage current exceeds the preset threshold of the test case, the system immediately cuts off the high-voltage output and determines it as a withstand voltage breakdown.

[0031] S3. Automated Dynamic Load Voltage Drop Test: This involves controlling a multiplexer to connect a DC-DC power supply to the power circuit of the harness under test and outputting operating current. Under stable load conditions, the voltage drop parameters of the power circuit are acquired, and the load capacity of the power circuit is evaluated based on these parameters. This step utilizes the programmable characteristics of the DC-DC power supply to simulate current surges under extreme conditions such as vehicle startup and high-power operation. Specific operations include: outputting the rated operating current to the power circuit via the DC-DC power supply, typically targeting critical power paths such as the grounding circuit or motor power supply circuit. The system initiates a preset stabilization delay after the output current to allow the electromagnetic induction and thermal effects of the circuit to stabilize before starting the sampling program, thus eliminating measurement deviations caused by transient current fluctuations.

[0032] After the load current stabilizes, the voltage at the far end of the power circuit is measured using a measuring instrument (such as the voltage setting of a digital multimeter). The system then automatically calculates the difference between the output voltage of the direct current control power supply and this far-end voltage, thus obtaining the circuit voltage drop parameter. If this voltage drop parameter exceeds a preset threshold, it is determined that the power circuit has a potential problem of excessive contact resistance or insufficient wire diameter, as an excessive voltage drop directly reflects the compliance of the circuit's load capacity. Through this load test, the system can accurately locate hidden loose connections that perform normally under static continuity testing but will heat up or even burn out under actual high-current operating conditions, fundamentally improving the quality control capability of critical safety circuits in the vehicle.

[0033] S4. Comprehensive Judgment: Integrate the test data from the above steps and output the judgment result. After all preset test items (continuity, insulation, withstand voltage, and dynamic voltage drop) have been executed, the controller processing unit will retrieve the judgment logic model from the background database and perform a weighted evaluation of the multi-dimensional measurement values ​​of each circuit. If any indicator fails to meet the qualification standard required by the test case, the system will automatically mark the entire harness as "unqualified". To prevent misjudgment due to single-sample error, the system integrates a confidence filtering algorithm. For critical data on the verge of judgment, the operator will be prompted to re-examine or the system will automatically initiate high-frequency secondary sampling to ensure the authority and accuracy of the judgment result.

[0034] In step S4, if the judgment result is unqualified, the system will immediately trigger the failure analysis module and output structured failure information. This failure information includes, but is not limited to: the failed connector code, specific pin number, failure type (such as excessive continuity, insulation breakdown, excessive voltage drop, etc.), measured physical value, and the corresponding standard threshold. This information will be presented on the operation interface in a visual graphical format, highlighting fault points in the harness topology diagram to guide maintenance personnel to quickly locate physical defects, thereby significantly shortening rework time. Simultaneously, the system will archive these failure characteristics in real time to the fault mode library as the original basis for subsequent harness process improvements.

[0035] Finally, the system automatically generates a complete inspection report. In addition to basic judgment results, this report records environmental parameters such as ambient temperature, humidity, and real-time power curves of the programmable power supply during testing, providing comprehensive data support for in-depth analysis of complex failure modes. The generated report supports automatic uploading to the Manufacturing Execution System (MES) or Quality Management System (QMS) via encryption protocols, achieving a closed-loop digital quality tracking system from parts arrival to vehicle rollout. Furthermore, the system has local redundant storage capabilities, ensuring that inspection data is fully preserved and supports offline export even in extreme situations such as network failures. Through this fully automated process, this invention achieves unmanned operation from test case loading to final data archiving, significantly improving the delivery quality of vehicle wiring harnesses under complex and variable configurations.

[0036] The execution logic and determination result of the method described in this invention can be achieved through... Figure 2The illustrated process is further explained. During system operation, the wiring harness information is first scanned and corresponding test cases are obtained through step S1. After confirming the wiring harness test content, automated wiring harness testing is performed. During the test, the controller processing unit compares the real-time measured values ​​with the preset thresholds of the test cases: if the measurement result shows continuity and the resistance value is lower than the preset threshold, the system determines the result as "OK" and drives the printer to print a qualified label; if the measurement value shows no continuity, or although it is continuous but the resistance value is higher than the preset threshold (i.e., there is a potential for a loose connection), the system determines the result as "NOK" and outputs failure determination information, simultaneously printing a non-conformance label for subsequent repair traceability. This closed-loop control process ensures complete automation from front-end information identification to back-end result processing, eliminates human judgment errors, and achieves efficient and accurate detection of electrical failures in the vehicle wiring harness.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An automated detection system for electrical failures of vehicle wiring harnesses based on a programmable power supply, characterized in that, The system includes: The controller processing unit is used to execute detection programs, coordinate the operation of the control system, and determine failures. A direct-flow controlled power supply, connected to the controller processing unit, is used to output controlled voltage and current according to instructions to simulate the vehicle power supply conditions. A multiplexer is connected to the DC flow control power supply and the measuring instrument unit respectively, and is used to switch the test path under the control of the controller processing unit; A measuring instrument unit is used to acquire the electrical parameters of the wiring harness; and A universal standard connector adapter is used to provide a physical interface between the multiplexer and the wiring harness of the vehicle under test.

2. The system according to claim 1, characterized in that, The measuring instrument unit includes a digital multimeter unit, an insulation resistance testing unit, and a withstand voltage testing unit.

3. The system according to claim 1, characterized in that, The direct current controlled power supply has adjustable output voltage and current, and is used to provide excitation for the test circuit and simulate static output conditions or dynamic load conditions.

4. An automated detection method for electrical failures of a vehicle wiring harness based on the system described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Load the test cases and connect the wiring harness to be tested; S2. Automated static electrical parameter testing: Control the multiplexer to switch the test circuit, obtain the conduction characteristics, insulation performance or withstand voltage performance parameters of the wire harness under test through the measuring instrument unit, and compare them with the preset threshold to make a judgment; S3. Automated dynamic load voltage drop test: Control the multiplexer to connect the DC dynamic control power supply to the power circuit of the wire harness under test and output the working current. Under stable load conditions, obtain the voltage drop parameters of the power circuit and evaluate the load capacity of the power circuit based on the voltage drop parameters. S4. Comprehensive Judgment: Integrate the test data from each step and output the judgment result.

5. The method according to claim 4, characterized in that, The continuity test in step S2 includes: measuring the continuity resistance between two terminals designed to be connected; if the continuity resistance exceeds a preset threshold or is infinite, it is determined to be a loose connection or an open circuit.

6. The method according to claim 4, characterized in that, The insulation performance test in step S2 includes: connecting the high-voltage terminal of the measuring instrument unit to the conductor under test, grounding the remaining conductors and shielding layer, applying a test voltage, and reading the insulation resistance value.

7. The method according to claim 4, characterized in that, The withstand voltage test in step S2 includes: connecting the measuring instrument unit between the circuit under test and ground, applying a preset high voltage and monitoring the leakage current.

8. The method according to claim 4, characterized in that, Step S3 specifically includes: The rated operating current is output to the power circuit through the DC-controlled power supply; the voltage value at the far end of the power circuit is measured through the measuring instrument unit; the difference between the output voltage of the DC-controlled power supply and the voltage value at the far end is calculated to obtain the voltage drop parameter.

9. The method according to claim 4, characterized in that, The power circuit mentioned in step S3 includes a grounding wire circuit or a motor power supply line circuit; if the voltage drop parameter exceeds a preset threshold, it is determined that there is excessive contact resistance or insufficient wire diameter.

10. The method according to claim 4, characterized in that, In step S4, if the judgment result is unqualified, failure information is output. The failure information includes at least one of the following: failure connector code, pin number, failure type, measured value, and standard value.

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