An automatic variable range test device for automobile static current test

Abstract

The invention discloses an automatic variable range test device for automobile static current test, including a test circuit, a data acquisition system and a host computer; the test circuit includes multiple shunts of different ranges, multiple relays K, a battery and a vehicle load; each shunt is connected in series with a relay K to form a range acquisition branch; one end of the multiple range acquisition branches is connected to the negative electrode of the battery as a current output end after the convergence and intersection; the other end of the multiple range acquisition branches is connected to the positive electrode of the battery through the vehicle load as a current input end after the convergence and intersection; the data acquisition system is connected to the data output end of each shunt in the test circuit respectively; the host computer is connected to the data acquisition system. The invention can automatically detect the current flowing through the shunt, automatically adjust the range, and compensate the static current value of the automobile according to the ambient temperature of the vehicle load, so as to realize accurate testing of the static current of the automobile.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle control, in particular to an automatic variable range testing device for automobile static current testing. Background Art

[0002] With the rapid development of the modern automobile industry, the complexity of vehicle electronic systems is increasing day by day. In order to ensure the safety, reliability and efficiency of automobiles, it is particularly important to perform static current testing on automotive electronic systems.

[0003] Quiescent current (also called dark current or standby current) refers to the current consumed by electronic devices in a car when the car is off (i.e., the car ignition switch is turned off). Monitoring this current is critical for evaluating vehicle battery life, optimizing energy management, and detecting potential electrical faults.

[0004] A shunt is an instrument for measuring DC current. It is made based on the principle that voltage is generated across a resistor when DC current passes through it. Traditional shunts usually require manual range adjustment, which is not only time-consuming and inefficient, but also prone to inaccurate test results due to improper operation or inaccurate readings.

[0005] In addition, due to the extensive use of sensitive electronic devices and complex network communication systems in modern automobiles, the existing manual testing method of manually adjusting the shunt range is difficult to adapt to the needs of rapid changes and technological upgrades.

[0006] Therefore, it is urgent to develop a technology that can solve the above technical problems. Summary of the invention

[0007] The purpose of the present invention is to provide an automatic variable range test device for automobile static current testing in view of the technical defects in the prior art.

[0008] To this end, the present invention provides an automatic variable range test device for automobile static current testing, which includes a test circuit, a data acquisition system and a host computer;

[0009] The test circuit includes multiple shunts with different ranges, multiple relays K, batteries and vehicle loads;

[0010] Each shunt is connected in series with a relay K to form a range acquisition branch;

[0011] One end of the multiple range acquisition branches, after the convergence and intersection, is used as the current output end and connected to the negative pole of the battery;

[0012] The other end of the multiple range acquisition branches, after convergence and intersection, serves as the current input end and is connected to the positive electrode of the battery through the vehicle load;

[0013] A data acquisition system is connected to the data output end of each shunt in the test circuit, and is used to collect the real-time current value of the range acquisition branch where each shunt is located in real time, and then send it to the host computer;

[0014] The host computer is connected to the data acquisition system and is used to receive the real-time current value of each range acquisition branch in real time, and control the switches of the multiple range acquisition branches in real time according to the maximum value of the multiple real-time current values, so that only the range acquisition branch where the range qualified shunt is located is in a closed state and the real-time current value of the range acquisition branch is displayed, and the real-time current value is used as the static current of the car before temperature compensation;

[0015] A qualified range shunt, i.e., a shunt whose range covers the maximum value among multiple real-time current values;

[0016] The upper computer is also used to perform a preset temperature compensation operation on the real-time current value collected from the range collection branch where the qualified range shunt is located, to obtain the compensated real-time current value, and use the compensated real-time current value as the temperature-compensated static current of the car. The temperature-compensated static current of the car is the static current of the car obtained by the final test;

[0017] The preset temperature compensation operation specifically includes the following steps:

[0018] Step 1: Collect environmental parameters: collect the temperature value of the environment where the vehicle load is located;

[0019] Step 2: Establish compensation model: Establish compensation model according to the static current and environmental parameters of the car before temperature compensation;

[0020] Compensation model, specifically: the quiescent current of the car after temperature compensation = the quiescent current of the car before temperature compensation + k * (ambient temperature - reference temperature);

[0021] Among them, the static current of the car after temperature compensation is the real-time current value of the car after temperature compensation;

[0022] The static current of the car before temperature compensation is the real-time current value collected from the range collection branch where the range qualified shunt is located;

[0023] k is the temperature compensation coefficient;

[0024] Step 3: Execute the compensation model to obtain the quiescent current of the car after temperature compensation.

[0025] It can be seen from the technical solution provided by the present invention above that, compared with the prior art, the present invention provides an automatic variable range test device for automobile static current testing, which is scientifically designed and can automatically detect the current flowing through the shunt, and automatically adjust the range of the measuring device of the present invention according to the actual current value flowing through the shunt, and can compensate for the static current value of the automobile according to the temperature of the environment where the whole vehicle load is located, and finally test and obtain the static current of the automobile, thereby realizing accurate testing of the static current of the automobile, ensuring the accuracy of the test results, and then ensuring the safety of the vehicle, which has great practical significance.

[0026] The present invention controls multiple relays through a host computer, and automatically adjusts the range of the measuring device of the present invention according to the actual current value flowing through the shunt, thereby optimizing the complicated process of readjusting the range or replacing the measuring device for each test of the traditional shunt, and greatly improving the test efficiency of the static current of the automobile.

[0027] For the present invention, the host computer can also replace the manual operation control test, which not only protects the personal safety of the tester, but also improves the accuracy of the test, and effectively ensures the safety and reliability of the static current test of the automobile.

[0028] For the present invention, various aspects of vehicle information can also be collected through the data acquisition system, which is conducive to a comprehensive analysis of the impact on the vehicle under different circumstances and can improve the effectiveness of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The overall circuit structure diagram of an embodiment of an automatic variable range test device for automobile static current test provided by the present invention;

[0030] Figure 2 The present invention provides a control principle block diagram of an embodiment of an automatic variable range test device for automobile static current testing. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0034] See also Figure 1 , Figure 2 , the present invention provides an automatic variable range test device for automobile static current test, including a test circuit, a data acquisition system and a host computer;

[0035] The test circuit includes several shunts with different ranges (e.g. Figure 1 The first shunt 1 and the second shunt 2 shown are not limited to two shunts), a plurality of relays K (for example Figure 1 The relay K1 and relay K2 shown are not limited to two relays), battery and vehicle load;

[0036] Each shunt is connected in series with a relay K to form a range acquisition branch;

[0037] One end of the multiple range acquisition branches, after the convergence and intersection, is used as the current output end and connected to the negative pole of the battery;

[0038] The other end of the multiple range acquisition branches, after convergence and intersection, serves as the current input end and is connected to the positive electrode of the battery through the vehicle load;

[0039] A data acquisition system is connected to the data output end of each shunt in the test circuit, and is used to collect the real-time current value of the range acquisition branch where each shunt is located in real time, and then send it to the host computer;

[0040] The host computer is connected to the data acquisition system and is used to receive the real-time current value of each range acquisition branch in real time. According to the maximum value of multiple real-time current values, the switches of multiple range acquisition branches are controlled in real time, so that only the range acquisition branch where the qualified range shunt (that is, the shunt whose range covers the maximum value of multiple real-time current values) is located is in a closed state and the real-time current value of the range acquisition branch is displayed, and the real-time current value is used as the static current of the car before temperature compensation.

[0041] In terms of specific implementation, the upper computer is specifically used to execute the current detection mode: when the maximum value among multiple real-time current values ​​is within the range of one or more shunts, the one or more shunts are defined as qualified range shunts, and a closing control signal is sent in real time to the relay K on the range collection branch where the qualified range shunt is located to control the closing, and a disconnection control signal is sent to the remaining shunts (i.e., the remaining shunts with smaller ranges) except the qualified range shunt and control the disconnection, and at the same time, the average value of the real-time current value of the range collection branch where the qualified range shunt is located is collected and displayed, and the average value of the real-time current value is used as the static current of the car before temperature compensation.

[0042] In specific implementation, when there are multiple qualified range shunts, the host computer only sends a control signal to the relay K on the range collection branch where one of the qualified range shunts is located and controls the closure.

[0043] Preferably, the host computer is used to send a closing control signal to relay K on the range collection branch where a qualified range shunt with the smallest range maximum value indication is located and control the closing when there are multiple qualified range shunts, and send a disconnection control signal to the remaining shunts and control the disconnection, and at the same time collect and display the real-time current value of the range collection branch where the qualified range shunt with the smallest range maximum value indication is located, and use the real-time current value as the static current of the car before temperature compensation.

[0044] It should be noted that, for the present invention, it is only necessary to make one range acquisition branch meet the range requirement of the static current to perform the test. This requirement is conducive to ensuring that the range of the shunt meets the measurement requirement of the static current while ensuring the accuracy of the static current measurement, because the closer the maximum value of the shunt range is to the actual static current value, the higher the progress of the static current measurement result.

[0045] In the present invention, in a specific implementation, the test circuit includes a plurality of shunt units with different ranges, which can be automatically switched as needed.

[0046] In order to understand the present invention more clearly, the technical solution of the present invention is described below in conjunction with specific embodiments.

[0047] In an embodiment of the present invention, the test circuit includes two shunts and two relays.

[0048] See also Figure 1 As shown, the test circuit specifically includes a first shunt 1, a second shunt 2, a relay K1, a relay K2, a battery and a vehicle load;

[0049] The first shunt 1 and the relay K1 are connected in series to form a first range acquisition branch;

[0050] The second shunt 2 and the relay K2 are connected in series to form a second range acquisition branch;

[0051] One end of the first range acquisition branch and the second range acquisition branch, after the convergence and intersection, is connected to the negative electrode of the battery as a current output end;

[0052] The other end of the first range acquisition branch and the second range acquisition branch, after the convergence and intersection, serves as a current input end and is connected to the positive electrode of the battery through the vehicle load;

[0053] It should be noted that the relay K1 is used to control the on / off of the first range acquisition branch; the relay K2 is used to control the on / off of the second range acquisition branch.

[0054] It should be noted that the first shunt 1 and the second shunt 2 are shunts with different measuring ranges. For example, the first shunt 1 is a shunt with a measuring range of 100A, which is used for large-range current measurement; the second shunt 2 is a shunt with a measuring range of 50mA, which is used for small-range current measurement.

[0055] Therefore, the second range acquisition branch is a small range acquisition branch, and the current value of the static current to be tested is in the range of 0-50mA, so this small range acquisition branch is used; the first range acquisition branch is a large range acquisition branch, and the current value of the static current to be tested is greater than 50mA, so this large range acquisition branch is used.

[0056] A data acquisition system is connected to the data output ends of the first shunt 1 and the second shunt 2 in the test circuit, respectively, and is used to collect in real time a first real-time current value of a first range acquisition branch where the first shunt 1 is located, and to collect in real time a second real-time current value of a second range acquisition branch where the second shunt is located, and then send the data to a host computer;

[0057] The upper computer is connected to the data acquisition system and is used to receive in real time a first real-time current value of the first range acquisition branch and a second real-time current value of the second range acquisition branch, and to control the switches of the first range acquisition branch and the second range acquisition branch in real time according to the maximum value of the first real-time current value and the second real-time current value, so that only the range acquisition branch where one of the range qualified shunts is located is in a closed state and displays the real-time current value of the range acquisition branch, and uses the real-time current value as the static current of the car before temperature compensation.

[0058] In the embodiment of the present invention, in specific implementation, the host computer is specifically used to execute the first current detection mode: when the maximum value of the first real-time current value and the second real-time current value is within the range of the second shunt 2 itself (i.e., the small-range current value range) (for example, less than 50 mA), the second shunt is defined as a qualified range shunt, and a control signal is sent to the relay K1 and the relay K2 in real time to control the closing of the relay K2 and the disconnection of the relay K1, thereby closing the second range acquisition branch where the second shunt 2 is located, and disconnecting the first range acquisition branch where the first shunt 1 is located;

[0059] Furthermore, the host computer is also used to execute the second current detection mode: when the maximum value of the first real-time current value and the second real-time current value is not within the measuring range of the second shunt 2 itself (i.e., the small-range current value range), but is within the measuring range of the first shunt 1 itself (for example, greater than 50mA), the first shunt is defined as a qualified-range shunt, and control signals are sent to relay K1 and relay K2 in real time to control the closing of relay K1 and the opening of relay K2, thereby closing the first-range acquisition branch where the first shunt 1 is located, and opening the second-range acquisition branch where the second shunt 2 is located.

[0060] In a specific implementation, the measuring range of the first shunt 1 covers the measuring range of the second shunt 2 , and the maximum measuring range of the first shunt 1 (eg, 100A) is greater than the maximum measuring range of the second shunt 2 (eg, 50mA).

[0061] In specific implementation, in order to ensure that there is no instantaneous open circuit during the channel switching process, at the moment of channel switching, relay K1 and relay K2 are both in the energized state.

[0062] It should be noted that, for the present invention, when conducting a static current test on a car, it is necessary to record the current of the entire vehicle from the IGN=ON (fire) state to the OFF (fire) state, and then to the system sleep state. In the IGN=ON (fire) state, the system current of the entire vehicle is relatively large, which will exceed the range of the static current test sensor (i.e., the shunt). In order to ensure the integrity of the test data, the present invention is designed with a function of automatic switching of the static current range, that is, when the measured current is greater than 50mA (i.e., greater than the range of the second shunt 2), the device of the present invention automatically switches to the large-range acquisition branch (i.e., the first range where the first shunt 1 is located to collect DC) to collect the static current, thereby ensuring the integrity and continuity of the data record, allowing the device of the present invention to automatically adapt to the switching of the current range, and protecting the small-range channel from being impacted by large current.

[0063] In specific implementation, the current detection mode adopted by the present invention is not limited to the above two, and can also be used for multi-range current measurement according to user needs.

[0064] In the present invention, in a specific implementation, the vehicle load is the electrical equipment on the vehicle, for example, an electronic anti-theft device, a motor controller, an air conditioning controller, etc. on the electric vehicle.

[0065] In the present invention, in specific implementation, the data acquisition system transmits data to the host computer in the form of CAN bus.

[0066] It should be noted that, for the present invention, the data acquisition system transmits data to the computer as the host computer and stores it in the memory card of the offline detection device in the form of CAN bus, realizing synchronous storage and preventing data loss due to the crash of the host computer.

[0067] In the present invention, in a specific implementation, the data acquisition system is also used to collect in real time through the first shunt 1 the first real-time voltage value of the first range acquisition branch where the first shunt 1 is located, and to collect in real time through the second shunt 2 the second real-time voltage value of the second range acquisition branch where the second shunt is located, and then send it to the host computer;

[0068] The host computer is also used to receive in real time a first real-time voltage value of the first range acquisition branch and a second real-time voltage value of the second range acquisition branch, and store them.

[0069] It should be noted that, for the present invention, the host computer is also used to synchronously monitor voltage data, with the maximum voltage being 60V.

[0070] In specific implementation, the host computer is also connected to the sound and light alarm device, and is also used to send a trigger signal to the sound and light alarm device when the first real-time voltage value or the second real-time voltage value is greater than the preset voltage alarm value (for example, 60V), thereby triggering the sound and light alarm device to sound an alarm.

[0071] For example, when the monitored voltage is greater than 60V (preset voltage alarm value), the host computer sends a trigger signal to the sound and light alarm device, triggering the sound and light alarm device to perform sound and light alarm operation. Therefore, for the present invention, the working status of the test system can be prompted through the sound and light alarm device.

[0072] In a specific implementation, the host computer is also connected to a display device (such as a monitor) for displaying the collected data in real time.

[0073] In the present invention, in a specific implementation, the battery can be a 12V or 24V battery.

[0074] In the present invention, in specific implementation, the data acquisition system and the sound and light alarm device can adopt the finished products that are mature in existing technology and have been put into wide application.

[0075] In specific implementation, the data acquisition system of the present invention can use the TRION3-1810M-POWER data acquisition module of the DEWETC brand to receive real-time data such as current and voltage information of each branch. In addition, data acquisition system products with similar effects can be used as substitutes.

[0076] In specific implementation, the sound and light alarm device of the present invention adopts the sound and light alarm device of Hangya brand and model YS-BJ02, which has an adjustable sound level of 110 decibels and a warning effect of flashing LED. In addition, sound and light alarm device products with similar effects can be used as substitutes.

[0077] In the present invention, the specific implementation is as follows: Figure 1 As shown, for the test circuit, the data acquisition output end of the thermocouple T1 built into the relay K1 and the data acquisition output end of the thermocouple T2 built into the relay K2 are respectively connected to the data acquisition end of the host computer;

[0078] Thermocouple T1 and thermocouple T2 are used to send the temperature information collected by the two to the host computer.

[0079] The power supply end of the thermocouple T1 and the power supply end of the thermocouple T2 are respectively connected to a 12V DC power supply.

[0080] That is, relay K1 and relay K2 are temperature monitoring type relays.

[0081] In terms of specific implementation, relay K1 with built-in thermocouple T1 and relay K2 with built-in thermocouple T2 are well-known electrical components with mature prior art. For example, Siemens temperature control relay model 3RS1121-1DW30 produced by Xiyuan Mechanical and Electrical Equipment Business Department of Huangpu District, Guangzhou can be used. This relay is mainly used for temperature monitoring and heating treatment of battery packs, electric motors and other special areas. Temperature control is used to ensure that various key components of the vehicle operate within the optimal temperature range, thereby improving the performance and reliability of the entire vehicle.

[0082] It should be noted that, for the present invention, the relays K1 and K2 in the test circuit are both equipped with built-in thermocouples, so that dynamic compensation can be performed for the change in the resistance value of the high-precision resistor at different temperatures to ensure the measurement accuracy, and a 12V power supply is used to power the device;

[0083] In the present invention, in the test circuit, the actual resistance value of the resistor (or the measured resistor) on the device under test (i.e., the vehicle load of the automobile) may be offset due to temperature changes. The internal resistance of the resistor in the device under test will also change accordingly when the temperature of the working environment of the device under test fluctuates. Therefore, it is necessary to compensate the static current value measured by the device at different temperatures accordingly to eliminate the influence of temperature changes on the measurement results.

[0084] In terms of specific implementation, in order to further improve the measurement accuracy of the static current, the host computer is also used to perform a preset temperature compensation operation on the real-time current value collected from the range collection branch where the qualified range shunt is located, to obtain the compensated real-time current value, and use the compensated real-time current value as the static current of the car after temperature compensation. The static current of the car after temperature compensation is the static current of the car obtained in the final test.

[0085] The preset temperature compensation operation specifically includes the following steps:

[0086] Step 1: Collect environmental parameters: collect the temperature value of the environment where the vehicle load is located;

[0087] In the first step, in terms of specific implementation, the temperature value of the environment where the entire vehicle load is located can be collected through a temperature sensor; the temperature sensor can be installed near or inside the object to be measured (i.e., the entire vehicle load of the car) to obtain accurate ambient temperature.

[0088] In addition, in the first step, a temperature value can be collected through the thermocouple T1 built into the relay K1 and the thermocouple T2 built into the relay K2, respectively, and the average of the two temperature values ​​is used as the temperature value of the environment where the entire vehicle load is located.

[0089] Step 2: Establish compensation model: Establish compensation model according to the static current and environmental parameters of the car before temperature compensation;

[0090] Compensation model, specifically: the quiescent current of the car after temperature compensation = the quiescent current of the car before temperature compensation + k * (ambient temperature - reference temperature);

[0091] The static current of the car after temperature compensation is the real-time current value of the car after temperature compensation, which is also the static current of the car obtained by the final test;

[0092] The static current of the car before temperature compensation is the real-time current value collected from the range collection branch where the range qualified shunt is located;

[0093] k is a coefficient, which is the temperature compensation coefficient. It is used to adjust the effect of temperature change on the static current compensation result. It is equal to the ratio of the change in static current to the change in temperature.

[0094] The reference temperature is a fixed temperature value or a reference point of the ambient temperature, such as 25 degrees Celsius.

[0095] Step 3: Execute the compensation model to obtain the static current of the car after temperature compensation, which is the final test result.

[0096] In specific implementation, the compensated static current measurement value can also be verified to verify whether its value is within the static current value range of the vehicle when the vehicle is working normally, to ensure that the compensation effect meets expectations.

[0097] It should be noted that dynamic compensation plays an important role in the automatic variable range test device used for automotive static current testing, because changes in environmental factors (such as temperature) will affect the measurement accuracy. For this time, the static current test results of the device under test (i.e. the vehicle load of the vehicle) are dynamically compensated. Dynamic compensation plays a key role in ensuring the measurement accuracy and stability of the test device under different environmental conditions, reducing environmental interference, thereby improving the accuracy and reliability of static current measurement, and providing more accurate data support for subsequent analysis.

[0098] Based on the above technical solutions, it can be known that in the present invention, the host computer analyzes the data obtained by the data acquisition system, and when the test conditions are met, the measurement range of the static current can be automatically adjusted.

[0099] It should be noted that, for the present invention, for the automobile models off the production line, the total current consumption of the vehicle in the OFF state can be detected, and the current value ranges from 50A to 10mA. The present invention can test both large current and small current, and the small current accuracy is not less than 1mA, the resolution can reach μA, and it is displayed on one channel. The output waveform is directly displayed on the display screen connected to the host computer. Specifically, data (current data) with a length of 30min can be recorded, and the sampling rate can be 1000Hz. The recorded waveform data can be further averaged between the maximum and minimum values, or double cursor calculation can be performed, and then the corresponding calculation results are output.

[0100] Compared with the prior art, the automatic variable range test device for automobile static current test provided by the present invention has the following beneficial effects:

[0101] 1. The device of the present invention realizes accurate testing of the static current of the automobile by automatically detecting the current value and automatically adjusting the range according to the actual current value. Compared with the traditional shunt with manually adjusted range, the device of the present invention has higher testing efficiency and accuracy for the static current of the automobile, reduces the complexity of operation, and improves the reliability of the test.

[0102] 2. The device of the present invention has a built-in thermocouple in the test circuit, which can dynamically compensate for the change in the resistance value of the high-precision resistor at different temperatures, thereby reducing the impact of temperature changes on the measurement results.

[0103] 3. Based on the device of the present invention, memory card storage and computer synchronous data storage can be realized through the CAN bus to prevent data loss due to computer crash.

[0104] 4. The device of the present invention is portable and does not need to be used with a computer.

[0105] Any matters not described in the present invention are applicable to the prior art.

[0106] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An automatic variable range test device for automobile static current testing, It is characterized in that Including test circuit, data acquisition system and host computer; The test circuit includes multiple shunts with different ranges, multiple relays K, batteries and vehicle loads; Each shunt is connected in series with a relay K to form a range acquisition branch; One end of the multiple range acquisition branches, after the convergence and intersection, is used as the current output end and connected to the negative pole of the battery; The other end of the multiple range acquisition branches, after convergence and intersection, serves as the current input end and is connected to the positive electrode of the battery through the vehicle load; A data acquisition system is connected to the data output end of each shunt in the test circuit, and is used to collect the real-time current value of the range acquisition branch where each shunt is located in real time, and then send it to the host computer; The host computer is connected to the data acquisition system and is used to receive the real-time current value of each range acquisition branch in real time, and control the switches of the multiple range acquisition branches in real time according to the maximum value of the multiple real-time current values, so that only the range acquisition branch where the range qualified shunt is located is in a closed state and the real-time current value of the range acquisition branch is displayed, and the real-time current value is used as the static current of the car before temperature compensation; A qualified range shunt, i.e., a shunt whose range covers the maximum value among multiple real-time current values; The upper computer is also used to perform a preset temperature compensation operation on the real-time current value collected from the range collection branch where the qualified range shunt is located, to obtain the compensated real-time current value, and use the compensated real-time current value as the temperature-compensated static current of the car. The temperature-compensated static current of the car is the static current of the car obtained by the final test; The preset temperature compensation operation specifically includes the following steps: Step 1: Collect environmental parameters: collect the temperature value of the environment where the vehicle load is located; Step 2: Establish compensation model: Establish compensation model according to the static current and environmental parameters of the car before temperature compensation; Compensation model, specifically: the static current of the car after temperature compensation = the static current of the car before temperature compensation + k* (ambient temperature - reference temperature); Among them, the static current of the car after temperature compensation is the real-time current value of the car after temperature compensation; The static current of the car before temperature compensation is the real-time current value collected from the range collection branch where the range qualified shunt is located; k is the temperature compensation coefficient; Step 3: Execute the compensation model to obtain the quiescent current of the car after temperature compensation.

2. The automatic variable range test device for automobile static current test as claimed in claim 1, It is characterized in that The host computer is used to execute the current detection mode: when the maximum value among multiple real-time current values ​​is within the range of one or more shunts, the one or more shunts are defined as qualified range shunts, and a closing control signal is sent in real time to the relay K on the range collection branch where the qualified range shunt is located to control the closing, and a disconnection control signal is sent to the remaining shunts except the qualified range shunt to control the disconnection, and at the same time, the average value of the real-time current value of the range collection branch where the qualified range shunt is located is collected and displayed, and the average value of the real-time current value is used as the static current of the car before temperature compensation.

3. The automatic variable range test device for automobile static current test as claimed in claim 1, It is characterized in that The upper computer is used for sending a closing control signal to the relay K on the range acquisition branch where the qualified range shunt with the smallest range maximum value indication is located and controlling the closing when there are multiple qualified range shunts, and sending a disconnection control signal to the remaining shunts and controlling the disconnection, and at the same time collecting and displaying the real-time current value of the range acquisition branch where the qualified range shunt with the smallest range maximum value indication is located, and using the real-time current value as the static current of the car before temperature compensation.

4. The automatic variable range test device for automobile static current test as claimed in claim 1, It is characterized in that A test circuit, specifically comprising a first shunt (1), a second shunt (2), a relay K1, a relay K2, a battery and a vehicle load; The first shunt (1) and the relay K1 are connected in series to form a first range acquisition branch; The second shunt (2) and the relay K2 are connected in series to form a second range acquisition branch; One end of the first range acquisition branch and the second range acquisition branch, after the convergence and intersection, is connected to the negative electrode of the battery as a current output end; The other end of the first range acquisition branch and the second range acquisition branch, after the convergence and intersection, serves as a current input end and is connected to the positive electrode of the battery through the vehicle load; A data acquisition system is connected to the data output ends of the first shunt (1) and the second shunt (2) in the test circuit respectively, and is used to collect in real time a first real-time current value of a first range acquisition branch where the first shunt (1) is located, and to collect in real time a second real-time current value of a second range acquisition branch where the second shunt is located, and then send the data to a host computer; The upper computer is connected to the data acquisition system and is used to receive in real time a first real-time current value of the first range acquisition branch and a second real-time current value of the second range acquisition branch, and to control the switches of the first range acquisition branch and the second range acquisition branch in real time according to the maximum value of the first real-time current value and the second real-time current value, so that only the range acquisition branch where one of the range qualified shunts is located is in a closed state and displays the real-time current value of the range acquisition branch, and uses the real-time current value as the static current of the car before temperature compensation.

5. The automatic variable range test device for automobile static current test as claimed in claim 4, It is characterized in that The host computer is used to execute a first current detection mode: when the maximum value of the first real-time current value and the second real-time current value is within the range of the second shunt (2), the second shunt is defined as a qualified shunt, and a control signal is sent to the relay K1 and the relay K2 in real time to control the closing of the relay K2 and the opening of the relay K1, thereby closing the second range acquisition branch where the second shunt (2) is located and opening the first range acquisition branch where the first shunt (1) is located.

6. The automatic variable range test device for automobile static current test as claimed in claim 4, It is characterized in that The host computer is also used to execute the second current detection mode: when the maximum value of the first real-time current value and the second real-time current value is not within the range of the second shunt (2) itself, but is within the range of the first shunt (1) itself, the first shunt is defined as a qualified shunt, and a control signal is sent to the relay K1 and the relay K2 in real time to control the closing of the relay K1 and the opening of the relay K2, thereby closing the first range acquisition branch where the first shunt (1) is located, and opening the second range acquisition branch where the second shunt (2) is located.

7. The automatic variable range test device for automobile static current test as claimed in claim 6, It is characterized in that The measuring range of the first shunt (1) covers the measuring range of the second shunt (2).

8. The automatic variable range test device for automobile static current test as claimed in claim 4, It is characterized in that The data acquisition system is also used to collect, in real time through the first shunt (1), a first real-time voltage value of a first range acquisition branch where the first shunt (1) is located, and to collect, in real time through the second shunt (2), a second real-time voltage value of a second range acquisition branch where the second shunt is located, and then send the data to a host computer; The host computer is also used to receive in real time a first real-time voltage value of the first range acquisition branch and a second real-time voltage value of the second range acquisition branch, and store them; The data acquisition system transmits data to the host computer in the form of CAN bus.

9. The automatic variable range test device for automobile static current test as claimed in claim 8, It is characterized in that The host computer is also connected to the sound and light alarm device, and is also used to send a trigger signal to the sound and light alarm device when the first real-time voltage value or the second real-time voltage value is greater than the preset voltage alarm value, thereby triggering the sound and light alarm device to alarm.

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