Weighing system, method, vehicle and electronic device for a vehicle

Abstract

This application discloses a vehicle weighing system, method, vehicle, and electronic device. The method includes: a strain gauge sensor module composed of a Wheatstone bridge, the Wheatstone bridge including at least one strain gauge, which outputs a differential voltage signal when the strain gauge sensor module is powered by a DC excitation power supply; a temperature determination module connected to the strain gauge sensor module, used to determine the temperature signal of the strain gauge when the strain gauge sensor module is powered by a constant current source; a strain signal processing module connected to both the strain gauge sensor module and the temperature determination module, used to calibrate the differential voltage signal based on the temperature signal to obtain a calibrated differential voltage signal; and a control module connected to the strain signal processing module, used to map the calibrated differential voltage signal using a voltage-load mapping relationship to obtain the target load signal of the vehicle. This application solves the technical problem of low vehicle weighing accuracy.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically, to a vehicle weighing system, method, vehicle, and electronic equipment. Background Technology

[0002] With the rapid development of intelligent connected vehicles, overload control, and smart logistics, on-board real-time weighing technology has become a key basic function for engineering and logistics vehicles such as dump trucks, sanitation vehicles, and freight trucks. Compared with traditional static weighbridges, on-board real-time weighing technology can achieve dynamic and continuous weight monitoring during vehicle travel or loading and unloading.

[0003] In related technologies, strain gauge weighing solutions have become the mainstream technology in the field of vehicle weighing due to their simple structure, low cost, and convenient installation. This weighing solution involves attaching strain gauges to elastic bodies such as vehicle frames or leaf springs, and then utilizing the characteristic that the resistance of the strain gauges changes with the deformation of the elastic body to convert the load force into a measurable voltage signal, thereby realizing weight sensing. However, because the resistance value of the strain gauges not only changes with the mechanical strain caused by the load, but is also affected by ambient temperature and its own Joule self-heating, it drifts, resulting in serious inaccuracies in the weighing results, which cannot meet the engineering requirements of accuracy and long-term stability for dynamic vehicle weighing.

[0004] There is currently no effective solution to the technical problem of low vehicle weighing accuracy mentioned above. Summary of the Invention

[0005] This application provides a vehicle weighing system, method, vehicle, and electronic device to at least address the technical problem of low vehicle weighing accuracy.

[0006] According to one aspect of the embodiments of this application, a vehicle weighing system is provided. The system may include: a strain gauge sensor module, composed of a Wheatstone bridge, wherein the Wheatstone bridge includes at least one strain gauge, the strain gauge being used to output a differential voltage signal when the strain gauge sensor module is in DC excitation power supply mode, the differential voltage signal being used to characterize the measured load of the vehicle; a temperature determination module, connected to the strain gauge sensor module, for determining the temperature signal of the strain gauge when the strain gauge sensor module is in constant current source power supply mode; a strain signal processing module, connected to both the strain gauge sensor module and the temperature determination module, for calibrating the differential voltage signal based on the temperature signal to obtain a calibrated differential voltage signal; and a control module, connected to the strain signal processing module, for mapping the calibrated differential voltage signal using a voltage-load mapping relationship to obtain a target load signal of the vehicle, wherein the target load signal is used to characterize the actual load of the vehicle, and the voltage-load mapping relationship is used to represent the mapping relationship between different differential voltage signals and different load signals of the vehicle.

[0007] Optionally, the vehicle's weighing system also includes a strain gauge excitation switch module, connected to the strain gauge sensor module, used to control the strain gauge sensor module to operate in DC excitation power supply mode or exit DC excitation power supply mode.

[0008] Optionally, the control module is also connected to the strain gauge excitation switch module and is used to output a first timing control signal or a second timing control signal to the strain gauge excitation switch module. The first timing control signal is used to turn on the voltage transmission circuit between the DC excitation power supply and the strain gauge sensor module so that the strain gauge sensor module can work in the DC excitation power supply mode. The second timing control signal is used to turn off the voltage transmission circuit between the DC excitation power supply and the strain gauge sensor module so that the strain gauge sensor module can exit the DC excitation power supply mode.

[0009] Optionally, the control module is also connected to the temperature determination module and is used to output a third timing control signal or a fourth timing control signal to the temperature determination module. The third timing control signal is used to turn on the voltage transmission circuit between the constant current source and the strain gauge sensor module so that the strain gauge sensor module operates in the constant current source power supply mode. The fourth timing control signal is used to turn off the voltage transmission circuit between the constant current source and the strain gauge sensor module so that the strain gauge sensor module exits the constant current source power supply mode.

[0010] Optionally, the temperature determination module includes: a constant current source for outputting a constant current; a switch control unit for turning on the voltage transmission circuit between the constant current source and the strain gauge sensor module under the action of a third timing control signal, or for turning off the voltage transmission circuit between the constant current source and the strain gauge sensor module under the action of a fourth timing control signal; and a signal acquisition and amplification unit for measuring the resistance value of the strain gauge when the voltage transmission circuit between the constant current source and the strain gauge sensor module is turned on, and determining the temperature signal of the strain gauge based on the resistance value and a linear temperature model, wherein the linear temperature model is used to characterize the linear dependence between the resistance value of the strain gauge and the temperature signal.

[0011] Optionally, the strain signal processing module includes: a differential amplifier unit for receiving differential voltage signals and amplifying them to obtain amplified differential voltage signals; a digital-to-analog converter for outputting a zero-point compensation voltage that matches the current temperature of the vehicle, wherein the zero-point compensation voltage serves as a reference voltage for the differential amplifier unit and is used to calibrate the zero-point drift voltage caused by temperature changes in the amplified differential voltage signal, and the value of the zero-point compensation voltage is equal to and has the same polarity as the zero-point drift voltage; and a resistor unit for adjusting the amplification factor of the differential amplifier unit in amplifying the differential voltage signal.

[0012] According to another aspect of the embodiments of this application, a vehicle weighing method is also provided. This method is applied to a vehicle weighing system and includes: in response to a strain gauge sensor module being in a DC excitation power supply mode, acquiring differential voltage signals output by strain gauges in a Wheatstone bridge, wherein the Wheatstone bridge is used to construct the strain gauge sensor module, and the differential voltage signals are used to characterize the measured load of the vehicle; in response to the strain gauge sensor module being in a constant current source power supply mode, determining the temperature signal of the strain gauges; calibrating the differential voltage signals based on the temperature signals to obtain calibrated differential voltage signals; and mapping the calibrated differential voltage signals using a voltage-load mapping relationship to obtain a target load signal for the vehicle, wherein the target load signal is used to characterize the actual load of the vehicle, and the voltage-load mapping relationship is used to represent the mapping relationship between different differential voltage signals and different load signals of the vehicle.

[0013] Optionally, in response to the strain gauge sensor module being in constant current source power supply mode, determining the temperature signal of the strain gauge includes: in response to the strain gauge sensor module being in constant current source power supply mode, measuring the resistance value of the strain gauge; inputting the resistance value into a linear temperature model to determine the temperature signal of the strain gauge, wherein the linear temperature model is used to characterize the linear dependence between the resistance value of the strain gauge and the temperature signal.

[0014] According to another aspect of the embodiments of this application, a vehicle weighing device is also provided. The device may include: a data acquisition unit, configured to acquire differential voltage signals output by strain gauges in a Wheatstone bridge in response to a strain gauge sensor module being in DC excitation power supply mode, wherein the Wheatstone bridge is used to construct the strain gauge sensor module, and the differential voltage signals are used to characterize the measured load of the vehicle; a determination unit, configured to determine the temperature signal of the strain gauges in response to a strain gauge sensor module being in constant current source power supply mode; a calibration unit, configured to calibrate the differential voltage signals based on the temperature signals to obtain calibrated differential voltage signals; and a mapping unit, configured to map the calibrated differential voltage signals using a voltage-load mapping relationship to obtain a target load signal for the vehicle, wherein the target load signal characterizes the actual load of the vehicle, and the voltage-load mapping relationship represents the mapping relationship between different differential voltage signals and different load signals of the vehicle.

[0015] According to another aspect of the embodiments of this application, an electronic device is also provided, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of this application when it runs.

[0016] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0017] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0018] According to another aspect of the embodiments of this application, a computer program product is also provided, including a non-volatile computer-readable storage medium storing a computer program, which, when executed by a processor, implements the methods in various embodiments of this application.

[0019] According to another aspect of the embodiments of this application, a computer program is also provided, which, when executed by a processor, implements the methods of the various embodiments of this application.

[0020] In this embodiment, a vehicle weighing system is provided, which may include: a strain gauge sensor module composed of a Wheatstone bridge, wherein the Wheatstone bridge includes at least one strain gauge, the strain gauge being used to output a differential voltage signal when the strain gauge sensor module is in DC excitation power supply mode, the differential voltage signal being used to characterize the measured load of the vehicle; a temperature determination module connected to the strain gauge sensor module, used to determine the temperature signal of the strain gauge when the strain gauge sensor module is in constant current source power supply mode; a strain signal processing module connected to both the strain gauge sensor module and the temperature determination module, used to calibrate the differential voltage signal based on the temperature signal to obtain a calibrated differential voltage signal; and a control module connected to the strain signal processing module, used to map the calibrated differential voltage signal using a voltage-load mapping relationship to obtain a target load signal of the vehicle, wherein the target load signal is used to characterize the actual load of the vehicle, and the voltage-load mapping relationship is used to represent the mapping relationship between different differential voltage signals and different load signals of the vehicle. In other words, in this embodiment, the strain gauge sensor module achieves coordinated measurement of differential voltage and temperature signals through a time-division multiplexing power supply mode. Specifically, when the strain gauge sensor module is powered by a DC excitation power supply, it acquires the differential voltage signal output by the strain gauge; when powered by a constant current source, it acquires the temperature signal. This time-division multiplexing method allows acquisition of the strain gauge temperature signal without the need for an external temperature sensor. Subsequently, the differential voltage signal is calibrated using the strain gauge temperature signal to compensate for interference caused by resistance drift due to temperature changes. Finally, the calibrated differential voltage signal is mapped using the voltage-load mapping relationship to obtain the vehicle's target load signal. In other words, by using the time-division multiplexing of the same strain gauge, temperature and load can be simultaneously and synchronously sensed from the same source, at the same point, without the need for an external temperature sensor, significantly improving vehicle weighing accuracy and thus solving the technical problem of low vehicle weighing accuracy in related technologies. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a schematic diagram of a vehicle weighing system according to an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of a Wheatstone bridge according to an embodiment of this application;

[0024] Figure 3This is a schematic diagram of another vehicle weighing system according to an embodiment of this application;

[0025] Figure 4 This is a schematic diagram of another vehicle weighing system according to an embodiment of this application;

[0026] Figure 5 This is a schematic diagram of another vehicle weighing system according to an embodiment of this application;

[0027] Figure 6 This is a schematic diagram of another vehicle weighing system according to an embodiment of this application;

[0028] Figure 7 This is a flowchart of a vehicle weighing method according to an embodiment of this application;

[0029] Figure 8 This is a schematic diagram of a vehicle weighing device according to an embodiment of this application. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, functional component, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, functional components, or devices.

[0032] According to an embodiment of this application, a vehicle weighing system is provided. Figure 1 This is a schematic diagram of a vehicle weighing system according to an embodiment of this application, as shown below. Figure 1As shown, the vehicle's weighing system 100 includes: a strain gauge sensor module 101, a temperature determination module 102, a strain signal processing module 103, and a control module 104. The following sections will further describe each of these modules.

[0033] The strain gauge sensor module 101 is composed of a Wheatstone bridge, wherein the Wheatstone bridge includes at least one strain gauge. The strain gauge is used to output a differential voltage signal when the strain gauge sensor module is in DC excitation power supply mode. The differential voltage signal is used to characterize the measured load of the vehicle.

[0034] In this embodiment, the strain gauge sensor module 101 is composed of a Wheatstone bridge, wherein at least one bridge arm uses a metal strain gauge with strain-sensitive characteristics, and the remaining bridge arms are fixed resistors, forming a balanced bridge structure. Figure 2 This is a schematic diagram of a Wheatstone bridge according to an embodiment of this application, as shown below. Figure 2 As shown, the Wheatstone bridge consists of four resistors, R1 to R4, forming a balanced circuit structure. The bridge arm R1 can be a metal strain gauge with strain-sensitive characteristics.

[0035] Optionally, when the vehicle is under load, the frame or leaf spring undergoes elastic deformation, causing mechanical strain in the strain gauges of the aforementioned Wheatstone bridge. This results in a change in the resistance value of the strain gauges, disrupting the balance of the Wheatstone bridge and generating a differential voltage signal proportional to the load at its output. This differential voltage signal directly reflects the mechanical deformation sensed by the strain gauges and is the original sensing signal of the vehicle-mounted weighing system.

[0036] Optionally, in the aforementioned weighing mode, the strain gauge sensor module operates in a DC excitation power supply mode. In this mode, the DC excitation voltage is stably applied to the Wheatstone bridge, and the differential voltage signal is synchronously acquired and sent to the subsequent signal processing circuit to characterize the vehicle's current real-time load. In this way, while acting as a force-sensitive element, the strain gauge's output differential voltage signal fully preserves the physical information of load changes, providing fundamental data support for subsequent temperature compensation and load mapping.

[0037] The temperature determination module 102 is connected to the strain gauge sensor module and is used to determine the temperature signal of the strain gauge when the strain gauge sensor module is in constant current source power supply mode.

[0038] In this embodiment, the temperature determination module 102 is connected to the strain gauge sensor module 101 and is used to calculate the temperature signal of the strain gauge by measuring the total resistance value of the strain gauge bridge when the strain gauge sensor module is in constant current source power supply mode.

[0039] Optionally, when the vehicle's weighing system enters the temperature self-testing phase, the power supply mode of the strain gauge sensor module will switch from DC excitation power supply mode to constant current source power supply mode. In constant current source power supply mode, the individual resistors in the Wheatstone bridge of the strain gauge sensor module are not subject to strain interference caused by load, and the total resistance of all resistors drifts linearly only with temperature changes. In this case, the temperature determination module can acquire the voltage response across the Wheatstone bridge, combine it with the known constant current source value, and calculate the total resistance R_bridge(T) of the Wheatstone bridge under no-load conditions. Then, it combines the reference resistance R0 calibrated at a preset temperature (e.g., 25℃) at the factory and the temperature coefficient of resistance α ≈ 1.9 × 10⁻⁶ of the strain gauge material. -3 / ℃, the real-time temperature of the strain gauge is accurately calculated using the linear temperature model T=25+[R_bridge(T)-R0] / α·R0, and is used as the temperature signal of the strain gauge.

[0040] Optionally, since the temperature signal of the strain gauge comes directly from the strain gauge body, the positional deviation problem of the external temperature sensor is avoided, and the temperature and load are perceived from the same source, at the same point, and synchronously, providing a reliable basis for subsequent accurate temperature compensation of the differential voltage signal.

[0041] The strain signal processing module 103 is connected to the strain gauge sensor module and the temperature determination module, respectively, and is used to calibrate the differential voltage signal based on the temperature signal to obtain the calibrated differential voltage signal.

[0042] In this embodiment, the strain signal processing module 103 is connected to the strain gauge sensor module 101 and the temperature determination module 102, respectively, and is used to dynamically calibrate the differential voltage signal acquired in the previous excitation cycle based on the real-time temperature signal output by the temperature determination module.

[0043] Optionally, during the operation of the vehicle's weighing system, temperature drift can cause strain gauges to output different voltage signals under the same load, introducing zero-point offset and range error. The strain signal processing module 103 receives the temperature signal output from the temperature determination module and adjusts the zero-point bias voltage and amplification gain in the differential voltage signal according to a pre-calibrated temperature compensation mapping relationship, thereby offsetting the non-load-type voltage drift caused by temperature. The temperature compensation mapping relationship characterizes the mapping relationship between the real-time temperature signal of the strain gauge and the differential voltage zero-point offset and gain drift caused by the temperature signal. The calibrated differential voltage signal is no longer affected by temperature, truly reflecting the mechanical deformation caused by the vehicle load, providing a stable and reliable input signal for subsequent accurate calculation of the target load. This achieves adaptive, closed-loop temperature compensation without the need for an external temperature sensor, significantly improving the weighing consistency and long-term stability of the vehicle's weighing system in a wide temperature range environment.

[0044] The control module 104 is connected to the strain signal processing module and is used to map the calibrated differential voltage signal using the voltage load mapping relationship to obtain the target load signal of the vehicle. The target load signal is used to characterize the actual load of the vehicle, and the voltage load mapping relationship is used to represent the mapping relationship between different differential voltage signals and different load signals of the vehicle.

[0045] In this embodiment, the control module 104 is connected to the strain signal processing module 103 to receive the temperature-compensated differential voltage signal and, based on the factory-calibrated voltage-load mapping relationship, accurately convert the calibrated differential voltage signal into the actual target load signal of the vehicle.

[0046] Optionally, the aforementioned voltage-load mapping relationship is established by applying a known load to the vehicle at standard ambient temperature, collecting the corresponding differential voltage values, establishing a mathematical model (e.g., linear fitting curve or discrete lookup table) between voltage and load, and storing the model. During the actual operation of the vehicle's weighing system, the control module quickly retrieves or calculates the corresponding load value based on the currently calibrated differential voltage signal through interpolation or formula calculation, thereby outputting a high-precision target load signal. This target load signal accurately reflects the actual load of the vehicle during dynamic driving or loading / unloading processes, unaffected by temperature drift, component aging, or circuit gain fluctuations. It achieves a reliable and stable conversion from the original electrical signal to the engineering load, providing accurate and reliable weight data support for the intelligent monitoring, overload warning, and logistics scheduling of the vehicle-mounted weighing system.

[0047] In the vehicle weighing system described in this application, the strain gauge sensor module achieves coordinated measurement of differential voltage and temperature signals through a time-division multiplexing power supply mode. Specifically, when the strain gauge sensor module is powered by a DC excitation power supply, it acquires the differential voltage signal output by the strain gauge; when powered by a constant current source, it acquires the temperature signal of the strain gauge. This time-division multiplexing method allows the acquisition of the strain gauge temperature signal without the need for an external temperature sensor. Subsequently, the differential voltage signal is calibrated using the strain gauge temperature signal to compensate for interference caused by resistance drift due to temperature changes. Finally, the calibrated differential voltage signal is mapped using a voltage-load mapping relationship to obtain the vehicle's target load signal. In other words, by using the same strain gauge for time-division multiplexing, temperature and load can be sensed synchronously from the same source and point without the need for an external temperature sensor, significantly improving vehicle weighing accuracy and thus solving the technical problem of low vehicle weighing accuracy in related technologies.

[0048] The weighing system of the vehicle described above in this embodiment will be further described below.

[0049] As an optional embodiment, the system further includes: a strain gauge excitation switch module, connected to the strain gauge sensor module, for controlling the strain gauge sensor module to operate in DC excitation power supply mode or exit DC excitation power supply mode.

[0050] In this embodiment, the vehicle weighing system 100 also includes a strain gauge excitation switch module 105. Figure 3 This is a schematic diagram of another vehicle weighing system according to an embodiment of this application, such as... Figure 3 As shown, the strain gauge excitation switch module 105 is connected to the strain gauge sensor module 101 and is used to control the strain gauge sensor module to work in DC excitation power supply mode or exit DC excitation power supply mode.

[0051] Optionally, the strain gauge excitation switch module is connected to the strain gauge sensor module to precisely control whether the strain gauge sensor module operates in DC excitation power supply mode or exits DC excitation power supply mode. For example, during the weighing operation period of the vehicle's weighing system, the strain gauge excitation switch module can conduct the voltage transmission circuit between the DC excitation power supply and the strain gauge sensor module, controlling the strain gauge sensor module to operate in DC excitation power supply mode. This allows the DC excitation power supply to apply a stable voltage to the strain gauge sensor module, causing the Wheatstone bridge in the strain gauge sensor module to enter the working state. Consequently, the strain gauges in the Wheatstone bridge output a differential voltage signal proportional to the vehicle load for subsequent acquisition and processing. When the vehicle's weighing system is not operating during weighing operations, the strain gauge excitation switch module quickly cuts off the voltage transmission circuit between the DC excitation power supply and the strain gauge sensor module, controlling the strain gauge sensor module to exit DC excitation power supply mode. This stops the DC excitation power supply to the strain gauge sensor module, effectively suppressing the Joule self-heating effect caused by continuous current and significantly reducing resistance drift caused by temperature rise.

[0052] Optionally, after the strain gauge sensor module exits the DC excitation power supply mode, the vehicle's weighing system can simultaneously switch to a constant current source power supply mode. This non-weighing operating period is used to perform self-temperature measurement on the strain gauge resistance in the strain gauge sensor module, achieving "time-division multiplexing." That is, the same set of strain gauges is used for load sensing during the excitation period (e.g., DC excitation power supply mode) and for temperature self-checking during the non-excitation period (e.g., constant current source power supply mode). This strain gauge excitation switch module achieves high-speed, low-power switching through a metal-oxide-semiconductor (MOS) transistor or similar electronically controlled switching device. This ensures real-time weighing sampling and creates a necessary time window for sensor temperature compensation, making it a key supporting module for achieving a high-precision, low-power, sensorless vehicle weighing architecture.

[0053] As an optional embodiment, the control module is also connected to the strain gauge excitation switch module and is used to output a first timing control signal or a second timing control signal to the strain gauge excitation switch module. The first timing control signal is used to turn on the voltage transmission circuit between the DC excitation power supply and the strain gauge sensor module so that the strain gauge sensor module operates in the DC excitation power supply mode. The second timing control signal is used to turn off the voltage transmission circuit between the DC excitation power supply and the strain gauge sensor module so that the strain gauge sensor module exits the DC excitation power supply mode.

[0054] In this embodiment, Figure 4 This is a schematic diagram of another vehicle weighing system according to an embodiment of this application, such as... Figure 4 As shown, the control module 104 is connected to the strain gauge excitation switch module 105 and is used to output precise timing control signals to the strain gauge excitation switch module 105 to control the strain gauge sensor module 101 to work in the DC excitation power supply mode or to exit the DC excitation power supply mode, thereby realizing the intelligent switching of the strain gauge sensor module between the two working modes of "load measurement" and "temperature self-measurement".

[0055] Optionally, when the vehicle's weighing system enters the load measurement stage, the control module can output a first timing control signal (e.g., a high level or pulse signal) to the strain gauge excitation switch module, triggering the strain gauge excitation switch module to conduct the voltage transmission path between the DC excitation power supply and the strain gauge sensor module. This allows the DC power output from the DC excitation power supply to be stably applied to the strain gauge sensor module, controlling the strain gauge sensor module to operate in the DC excitation power supply mode. At this time, the strain gauge in the strain gauge sensor module can output a differential voltage signal reflecting the vehicle load. After the load measurement cycle ends, the control module can output a second timing control signal (e.g., a low level or a turn-off pulse) to the strain gauge excitation switch module, controlling the strain gauge excitation switch module to disconnect the connection between the DC excitation power supply and the strain gauge sensor module. This causes the DC excitation power supply to stop supplying power to the strain gauge sensor module, thereby causing the strain gauge sensor module to exit the DC excitation power supply mode. This effectively suppresses Joule self-heating caused by continuous power supply to the strain gauge sensor module and significantly reduces the temperature drift source.

[0056] Optionally, the strain gauge sensor module exits the DC excitation power supply mode, creating a critical time window for the strain gauge's temperature self-measurement. That is, after the strain gauge sensor module exits the DC excitation power supply mode, the power supply path of the strain gauge sensor module can be switched to the constant current source power supply path, thereby utilizing the absence of an excitation gap to complete the temperature sampling of the strain gauge resistance.

[0057] Optionally, by precisely coordinating the intelligent switching between the two working modes of "load measurement" and "temperature self-measurement" of the strain gauge sensor module through preset periodic timing logic (e.g., 100ms excitation, 900ms self-temperature measurement), it is possible to ensure that load weighing and temperature measurement do not interfere with each other and are seamlessly connected. This realizes the core technical path of "one bridge for dual use and time-division multiplexing" and is the core control logic for achieving a vehicle-mounted weighing system with no external temperature sensor and automatic zeroing across the entire temperature range.

[0058] As an optional embodiment, the control module is also connected to the temperature determination module and is used to output a third timing control signal or a fourth timing control signal to the temperature determination module. The third timing control signal is used to turn on the voltage transmission circuit between the constant current source and the strain gauge sensor so that the strain gauge sensor operates in the constant current source power supply mode. The fourth timing control signal is used to turn off the voltage transmission circuit between the constant current source and the strain gauge sensor so that the strain gauge sensor exits the constant current source power supply mode.

[0059] In this embodiment, Figure 5 This is a schematic diagram of another vehicle weighing system according to an embodiment of this application, such as... Figure 5 As shown, the control module 104 is also connected to the temperature determination module 102, and is used to output a third timing control signal or a fourth timing control signal to the temperature determination module 102 during the time-division multiplexing working cycle, so as to accurately control the on / off state of the power supply path between the constant current source and the strain gauge sensor module 101.

[0060] Optionally, when the vehicle's weighing system enters the temperature self-testing phase, the control module outputs a third timing control signal to the temperature determination module to trigger the closing of the switching circuit in the temperature determination module. This creates a stable current loop between the constant current source in the temperature determination module and the strain gauge sensor module. At this time, the DC excitation power supply is cut off, the strain gauge sensor module is not under load, and its overall resistance changes linearly only due to temperature. The constant current source provides a low-power, high-stability excitation current, generating a voltage signal across the Wheatstone bridge in the strain gauge sensor module that is proportional to the total resistance of the strain gauge sensor module. This voltage is amplified by an operational amplifier and fed back to the control module to accurately calculate the equivalent resistance value of the strain gauge in the Wheatstone bridge of the strain gauge sensor module. Based on a preset linear temperature model, the temperature signal of the strain gauge itself is then calculated.

[0061] Optionally, after the temperature signal of the strain gauge is measured, the control module can output a fourth timing control signal to the temperature determination module to trigger the temperature determination module to disconnect the connection between the constant current source and the strain gauge sensor module, close the temperature detection path, and prepare for the load measurement of the next cycle.

[0062] Optionally, the aforementioned timing control strictly follows the cyclic logic of "excitation weighing—excitation shutdown—constant current temperature measurement—constant current shutdown," ensuring complete temporal isolation and no interference between the two power supply modes (DC excitation power supply mode and constant current source power supply mode). This avoids interference from the DC excitation power supply to the strain gauge temperature measurement and prevents the constant current source from affecting the acquisition of the load signal. Through this precise timing coordination, the control module enables the same set of strain gauges to perform the dual functions of "load measurement" and "temperature self-measurement" at different stages, thereby significantly improving the measurement accuracy and long-term reliability of the vehicle's weighing system in complex automotive environments.

[0063] The following example illustrates the cyclic logic of "excitation weighing - excitation shutdown - constant current temperature measurement - constant current shutdown" followed by the timing control described above.

[0064] Optionally, the control module precisely coordinates the four-stage cyclic logic of "excitation weighing - excitation shutdown - constant current temperature measurement - constant current shutdown" to achieve intelligent switching and interference-free collaborative operation of the same set of strain gauges between load measurement and temperature self-testing functions. At the beginning of each working cycle, the control module outputs the first timing control signal to drive the strain gauge excitation switch module to conduct the path between the DC excitation power supply and the strain gauge sensor module, so that the strain gauge sensor module obtains a stable voltage excitation. At this time, the strain gauge in the strain gauge sensor module generates a resistance change under the load and outputs a differential voltage signal reflecting the vehicle weight. After amplification and processing, the differential voltage signal is sampled by the control module to calculate the actual load of the vehicle and complete one weighing task. After the weighing is completed, the control module immediately outputs the second timing control signal to cut off the power supply path between the DC excitation power supply and the strain gauge sensor module, so that the strain gauge bridge stops working and exits the excitation state. This effectively eliminates the Joule self-heating effect caused by continuous energization of the strain gauge, avoids nonlinear resistance drift caused by self-heating, and significantly reduces zero-point drift error caused by temperature disturbance, creating a stable, heat-free environment for subsequent high-precision temperature measurement.

[0065] Optionally, after disconnecting the DC excitation power supply from the strain gauge sensor module, the switch control unit in the temperature determination module can be activated to connect the current loop between the constant current source and the strain gauge sensor module, allowing the strain gauge sensor module to operate in constant current source power supply mode. In this mode, there is no load interference or excitation self-heating, and the strain gauge sensor module exhibits its inherent temperature resistance characteristics. The voltage signal driven by the constant current source, after acquisition and amplification, is used to accurately calculate the resistance of the strain gauge in the Wheatstone bridge within the strain gauge sensor module, and the temperature signal of the strain gauge itself is calculated based on a pre-calibrated linear temperature model. After the temperature signal acquisition is complete, the control module outputs a fourth timing control signal to disconnect the constant current source loop, ending the temperature measurement process and preparing for the next cycle of excitation and weighing. The entire cycle repeats continuously with a fixed timing sequence (e.g., 100ms excitation and weighing + 900ms constant current temperature measurement), ensuring complete temporal isolation between the two operating modes and preventing interference. No temperature measurement occurs during excitation, and no excitation occurs during temperature measurement, ensuring both the real-time performance and accuracy of the weighing, and achieving high-precision self-temperature measurement without external sensors. This "four-step cycle" logic is the core control basis of "time-division multiplexing, same-source temperature measurement, and automatic zeroing". It solves the technical problem of accuracy failure caused by temperature drift in traditional vehicle weighing. It has the advantages of high reliability, low power consumption and low cost, and significantly improves the long-term stability of the system in complex vehicle environments.

[0066] As an optional embodiment, the temperature determination module includes: a constant current source for outputting a constant current; a switch control unit for turning on the voltage transmission circuit between the constant current source and the strain gauge sensor under the action of a third timing control signal, or for turning off the voltage transmission circuit between the constant current source and the strain gauge sensor under the action of a fourth timing control signal; and a signal acquisition and amplification unit for measuring the resistance value of the strain gauge when the voltage transmission circuit between the constant current source and the strain gauge sensor is turned on, and determining the temperature signal of the strain gauge based on the resistance value and a linear temperature model, wherein the linear temperature model is used to characterize the linear dependence between the resistance value of the strain gauge and the temperature signal.

[0067] In this embodiment, the temperature determination module is composed of a constant current source, a switch control unit, and a signal acquisition and amplification unit, which is used to achieve high-precision self-temperature measurement of the strain gauge when the strain gauge sensor module exits the DC excitation power supply mode.

[0068] Optionally, when the control module outputs the third timing control signal, the switch control unit responds and connects the current path between the constant current source and the strain gauge sensor module. At this time, the power transmission circuit between the DC excitation power supply and the strain gauge sensor module is completely disconnected, and the strain gauge sensor module is in a static state without load or self-heating. Under these conditions, the constant current source can output a stable, low-power constant current, flowing through the entire Wheatstone bridge structure of the strain gauge sensor module, converting the total resistance of the bridge into a measurable voltage signal. This voltage signal is differentially acquired and amplified with low noise by the high input impedance operational amplifier circuit in the signal acquisition and amplification unit, eliminating the influence of external interference and line voltage drop, and ensuring that voltage fluctuations caused by weak resistance changes are accurately reproduced. Subsequently, based on the known output current value of the constant current source, the total resistance R_bridge(T) of the Wheatstone bridge under no-load conditions is calculated using Ohm's law. Since the resistances in the Wheatstone bridge other than the strain gauges are fixed, this total resistance can accurately reflect the change in the resistance of the strain gauges. Combined with the 25℃ reference resistance R0 calibrated at the factory and the temperature coefficient α of the strain gauge material, the temperature signal of the strain gauge is calculated in real time by substituting it into the linear temperature model T=25+[R_bridge(T)-R0] / α·R0.

[0069] Optionally, after the strain gauge temperature signal is measured, the control module outputs a fourth timing control signal. The switch control unit immediately disconnects the voltage loop between the constant current source and the strain gauge sensor module, terminating the temperature measurement process and preparing for the next excitation weighing cycle. This process does not rely on any external temperature sensor, but fully utilizes the resistance-temperature characteristics of the strain gauge itself to achieve temperature sensing from the same point, source, and material. This not only eliminates the risks of installation position deviation and wiring failure associated with traditional external negative temperature coefficient thermistors (NTC) sensors, but also improves temperature compensation accuracy because temperature measurement and stress sensing share the same physical entity.

[0070] As an optional implementation, the strain signal processing module includes: a differential amplifier unit for receiving differential voltage signals and amplifying them to obtain amplified differential voltage signals; a digital-to-analog converter for outputting a zero-point compensation voltage that matches the current temperature of the vehicle, wherein the zero-point compensation voltage serves as a reference voltage input for the differential amplifier unit and is used to calibrate the zero-point drift voltage caused by temperature changes in the amplified differential voltage signal, and the value of the zero-point compensation voltage is equal to and has the same polarity as the zero-point drift voltage; and a resistor unit for adjusting the amplification factor of the differential amplifier unit in amplifying the differential voltage signal.

[0071] In this embodiment, the strain signal processing module is composed of a differential amplifier unit, a digital-to-analog converter (DAC), and a resistor unit working together. Its core function is to eliminate zero-point drift and gain fluctuation caused by temperature changes in the load signal in real time, so as to achieve high-precision and adaptive load signal reconstruction.

[0072] Optionally, when the strain gauge sensor module operates in DC excitation mode, the differential voltage signal output by the Wheatstone bridge in the strain gauge sensor module carries load information, but also contains non-load-related offsets caused by temperature, i.e., zero-point drift voltage. The differential amplifier unit receives this differential voltage signal and amplifies it with high gain and low noise to improve the signal-to-noise ratio, facilitating subsequent digital processing. Simultaneously, the control module, based on the temperature signal fed back by the temperature determination module, looks up or calculates the corresponding zero-point compensation voltage value. This zero-point compensation voltage value is equal to the zero-point drift voltage measured at that temperature signal, but with opposite polarity. That is, a zero-point compensation voltage with the same magnitude and direction as the zero-point drift voltage is output through the DAC as the reference voltage input for the differential amplifier unit. This mechanism is essentially "active cancellation." For example, while amplifying the differential voltage signal, the differential amplifier unit superimposes the zero-point compensation voltage onto the reference terminal, ensuring that the net voltage at the output terminal only reflects the actual load changes of the vehicle, eliminating the zero-point offset in the differential voltage signal caused by temperature.

[0073] Optionally, to address sensitivity (gain) drift caused by temperature signals, the feedback network of the differential amplifier circuit can be dynamically adjusted using a resistor unit. For example, a programmable resistor or digital potentiometer can be used to fine-tune the amplification factor under control module commands, ensuring that the vehicle's weighing system maintains a consistent response to the same load at different temperatures. The adjustment parameters of this resistor unit are derived from the temperature compensation mapping relationship and work in conjunction with zero-point compensation to form a "dual-channel temperature calibration" mechanism. The entire process requires no manual intervention, achieving fully automatic conversion from the original weak differential signal to a stable and accurate engineering load value. This is a key technological support for achieving "automatic zeroing across the entire temperature range, no factory calibration required, and high long-term stability."

[0074] In the above steps, the strain gauge sensor module achieves coordinated measurement of differential voltage and temperature signals through a time-division multiplexing power supply mode. Specifically, when the strain gauge sensor module is powered by a DC excitation power supply, it acquires the differential voltage signal output by the strain gauge; when powered by a constant current source, it acquires the temperature signal. This time-division multiplexing method allows acquisition of the strain gauge temperature signal without the need for an external temperature sensor. Subsequently, the differential voltage signal is calibrated using the strain gauge temperature signal to compensate for interference caused by resistance drift due to temperature changes. Finally, the calibrated differential voltage signal is mapped using the voltage-load mapping relationship to obtain the vehicle's target load signal. In other words, by using the same strain gauge for time-division multiplexing, temperature and load can be sensed synchronously from the same source and point without an external temperature sensor, significantly improving vehicle weighing accuracy and thus solving the technical problem of low vehicle weighing accuracy in related technologies.

[0075] The weighing system for the vehicle described above will be further described below with reference to the preferred embodiments of this application.

[0076] Figure 6 This is a schematic diagram of another vehicle weighing system according to an embodiment of this application, such as... Figure 6 As shown, the weighing system 100 of the vehicle includes: a strain gauge sensor module 101, a temperature determination module 102, a strain signal processing module 103, a control module 104, and a strain gauge excitation switch module 105.

[0077] Optionally, such as Figure 6 As shown, the strain gauge sensor module 101 is composed of a Wheatstone bridge, which consists of four resistors R1 to R4 to form a balanced circuit structure. The upper arm R1 of the bridge is used as a strain gauge for stress measurement.

[0078] Optionally, such as Figure 6 As shown, the temperature determination module 102 consists of a constant current source V1, a switch control unit (MOSFET Q2 and MOSFET Q3), an acquisition and amplification unit (including operational amplifier U1A and feedback resistor R5), and a fixed resistor R6.

[0079] Optionally, the constant current source V1 serves as the excitation source for the self-temperature measurement stage. It starts after the control module outputs the third timing control signal, providing a stable, low-noise constant current to the Wheatstone bridge. Unlike traditional DC voltage excitation, constant current excitation directly and linearly converts the change in the total resistance of the Wheatstone bridge into a voltage signal, avoiding measurement errors caused by power supply fluctuations or changes in line impedance. This constant current source does not require high precision or high power; it only needs good temperature stability and low drift characteristics to meet the temperature measurement requirements in an automotive environment.

[0080] Optionally, the switch control unit (MOSFETs Q2 and Q3) consists of two P-channel or N-channel MOSFETs, which control the on / off path between the constant current source V1 and the Wheatstone bridge, respectively. MOSFET Q2 is connected in series between the constant current source V1 and the upper arm (R1) of the Wheatstone bridge to control whether the constant current is injected into the high end of the Wheatstone bridge; MOSFET Q3 is connected in series between the lower arm (R6) of the bridge and ground to establish the low-end path of the constant current circuit. When the vehicle's weighing system is in self-temperature measurement mode, MOSFETs Q2 and Q3 are simultaneously turned on. At this time, the constant current source V1 is used for power supply, and the voltage source VCC_BAR is cut off, forming a voltage signal feedback to R1 of the total resistance structure of the Wheatstone bridge and R6 of the lower arm of MOSFET Q3. The feedback signal is coupled and amplified by operational amplifier U1A, and R5 is used for parameter adjustment of the feedback amplified signal. However, when the vehicle's weighing system is in weighing mode, both MOSFETs Q2 and Q3 are turned off, ensuring that the constant current path is completely disconnected and avoiding interference with the differential excitation signal. This switch combination achieves electrical isolation and timing control of the constant current excitation path and is the core actuator for realizing time-division multiplexing of "excitation weighing" and "constant current temperature measurement".

[0081] Optionally, the fixed resistor R6 is the fixed resistor in the lower arm of the Wheatstone bridge structure, forming a series branch with the strain gauge R1. In self-temperature measurement mode, since R1 in the Wheatstone bridge is a variable resistor that changes with temperature, while R6 is a precision fixed resistor with an extremely low temperature coefficient, the change in the total resistance after they are connected in series is mainly dominated by the temperature drift of R1. The introduction of R6 not only forms a necessary path for the constant current loop, but also, through its series-parallel relationship with R1, ensures that the change in the total resistance of the bridge mainly reflects the temperature characteristics of R1, thereby ensuring the accuracy and repeatability of the temperature calculation. The resistance value of R6 is precisely calibrated at the factory and serves as one of the reference parameters for temperature model calculations.

[0082] Optionally, the signal acquisition and amplification unit consists of operational amplifier U1A and feedback resistor R5, used to acquire the voltage difference across the Wheatstone bridge under constant current excitation. Since the constant current source generates a voltage signal at the node between MOSFETs Q2 and Q3 after flowing through the Wheatstone bridge, this voltage is proportional to the total resistance of the Wheatstone bridge, but the signal amplitude is weak and easily contaminated by noise. Operational amplifier U1A operates in a differential configuration with high input impedance and low offset voltage, amplifying this weak voltage signal with high gain and low noise. Feedback resistor R5 is used to set the amplification factor. This unit achieves high-fidelity conversion from resistance change to voltage signal and is the core of the front-end signal processing for accurate temperature calculation.

[0083] Optionally, during the "constant current temperature measurement" stage, the control module triggers Q2 and Q3 to conduct, and the constant current source V1 injects a constant current into the equivalent resistance network composed of R1 (strain gauge), R6 and other arms of the bridge. The amplifier circuit composed of U1A and R5 collects and amplifies the voltage across the bridge and outputs an analog signal proportional to the total resistance. Based on this, the control module calculates R_bridge(T), and combined with the factory-calibrated R0 and temperature coefficient α, calculates the temperature of the strain gauge body, realizing high-precision self-temperature measurement without external sensors, at the same point and from the same source.

[0084] Optionally, such as Figure 6 As shown, the strain signal processing module 103 is composed of a differential amplifier unit (operational amplifier U2), a digital-to-analog converter (DAC), and a programmable resistor unit R. It is used to perform high-precision amplification, active temperature drift cancellation, and adaptive gain adjustment on the weak differential signal from the strain gauge bridge in DC excitation mode, so as to achieve automatic zeroing in the whole temperature range and high stability output of the load signal.

[0085] Optionally, such as Figure 6 As shown, the differential amplifier unit (operational amplifier U2) is a high-precision, low-offset, low-temperature-drift instrumentation amplifier or differential op-amp. Its input is directly connected to the two outputs of the Wheatstone bridge to extract the weak differential voltage signal of the Wheatstone bridge under excitation. This signal is generated by the resistance change of the strain gauge caused by vehicle load, and its amplitude is typically in the millivolt range, with a significant temperature drift component superimposed. Operational amplifier U2 amplifies this signal with high gain and high common-mode rejection ratio (CMRR) to improve the signal-to-noise ratio and ensure that the signal meets the dynamic range requirements of subsequent DAC sampling. Its amplification factor is determined by an external resistor network, which is dynamically adjusted by the resistor unit R, thereby achieving gain self-adaptation.

[0086] Optionally, the digital-to-analog converter (DAC) is the core digital-to-analog interface for implementing the automatic zeroing function. After each temperature self-test cycle is completed, the control module uses the real-time temperature value fed back by the temperature determination module to look up a table or calculate the zero-point drift voltage of the strain gauge at the current temperature (i.e., the output offset caused by temperature when there is no load) through a linear model. The DAC receives this digital instruction and outputs a precise analog compensation voltage with the opposite polarity to the zero-point drift. This voltage is injected into the reference input of the differential amplifier U2 (or used as a common-mode reference) to cancel the temperature drift, so that the final output of the differential amplifier U2 contains only the true load information.

[0087] Optionally, the resistor unit R is a dynamically adjustable resistor network used to adjust the gain (amplification factor) of the differential amplifier U2 to compensate for temperature-induced sensitivity drift.

[0088] Optionally, although the sensitivity coefficient of the strain gauge remains essentially unchanged at different temperatures, the Young's modulus of the elastomer material changes with temperature, causing a systematic shift in the resistance change per unit load, i.e., "gain drift". By controlling the resistor unit R according to the temperature data through the control module, the feedback resistance value of U2 can be dynamically adjusted, and the amplification factor can be corrected in real time, so that the vehicle's weighing system outputs a consistent voltage value for the same load at different temperatures.

[0089] Optionally, such as Figure 6 As shown, the control module 104 (MCU) is configured to: generate time-division multiplexed timing control signals to alternately drive the strain gauge to switch between excitation weighing mode and constant current temperature measurement mode; acquire the bridge voltage signal during the temperature measurement stage and calculate the real-time temperature of the strain gauge body; based on the temperature value, dynamically generate a zero-point compensation voltage and inject it into the differential amplifier circuit through a digital-to-analog converter, while adjusting the amplification gain to compensate for sensitivity drift, thereby realizing the automatic zeroing function of the entire temperature range without the need for an external temperature sensor.

[0090] Optionally, such as Figure 6 As shown, the strain gauge excitation switch module 105 is composed of a P-channel MOSFET Q1. This MOSFET Q1 acts as a switching element, turning on during the weighing phase of the vehicle's weighing system to supply power from the DC excitation power supply (VCC_BAR) to the Wheatstone bridge. During the temperature self-test phase, it turns off, disconnecting the DC excitation power supply from the Wheatstone bridge, causing the Wheatstone bridge to stop working and eliminating its Joule self-heating effect, thus providing a thermally interference-free physical environment for subsequent constant current temperature measurement. This strain gauge excitation switch module achieves timing control of the excitation path using only a single switching device. It features a simple structure, fast response, and extremely low power consumption, making it a key execution unit for realizing the "time-division multiplexing, same-source temperature measurement, and automatic zeroing" vehicle weighing architecture.

[0091] The weighing principle of the weighing system for the aforementioned vehicles will be further explained below.

[0092] In this embodiment, a time-division multiplexing mechanism is used to achieve intelligent switching between the two functions of weighing measurement and temperature self-testing for the same set of strain gauge bridges. High-precision, adaptive vehicle weighing can be completed without the need for an additional temperature sensor.

[0093] During the weighing measurement phase, a periodic excitation voltage is applied to the Wheatstone bridge via a DC excitation power supply (VCC_BAR), causing the bridge to generate a weak differential signal proportional to the strain under load. This signal is processed by a differential amplifier circuit and then sent to the control module for acquisition and digitization. To ensure measurement accuracy, the temperature self-testing loop is completely disconnected during this phase to avoid any external current interference. Simultaneously, the control unit dynamically adjusts the amplifier's zero-point compensation voltage and gain coefficient based on the temperature information measured in the previous cycle, achieving real-time correction of zero-point drift and sensitivity changes caused by temperature. This allows for automatic zeroing before each weighing without manual intervention.

[0094] After completing one weighing acquisition, the DC voltage excitation of the Wheatstone bridge is immediately stopped, allowing the strain gauges to cool down and eliminating the Joule self-heating effect caused by current flow. Then, the system switches to temperature self-measurement mode: a stable current is injected into the Wheatstone bridge through a low-power constant current source V1. At this point, the change in the total resistance of the bridge is mainly dominated by the temperature characteristics of its material. Since the DC excitation voltage has been cut off, the Wheatstone bridge is no longer affected by the load, and its total resistance is only related to the ambient temperature. By measuring the voltage across the bridge under constant current, the current total resistance value can be accurately calculated. Combining the reference resistance calibrated at the factory at a standard temperature (e.g., 25°C) and the known temperature coefficient of the strain gauge material, the system can accurately calculate the real-time temperature of the strain gauge body.

[0095] This temperature value is used to update the zeroing parameters for the next cycle, ensuring that zero-point compensation and gain adjustment are always synchronized with the actual temperature. The entire process is cyclical: weighing—power off—temperature measurement—calibration—re-weighing, forming a closed-loop adaptive system. This scheme utilizes the strain gauge itself as a temperature-sensitive element, achieving synchronous sensing of stress and temperature at the same physical location and on the same material basis. This avoids temperature measurement errors caused by different installation positions of external sensors. Furthermore, because it is powered off most of the time, it significantly reduces system power consumption and thermal drift, greatly improving long-term stability and environmental adaptability.

[0096] According to an embodiment of this application, an embodiment of a vehicle weighing method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0097] Figure 7 This is a flowchart of a vehicle weighing method according to an embodiment of this application, such as... Figure 7 As shown, the method may include the following steps.

[0098] Step S701: In response to the strain gauge sensor module being in DC excitation power supply mode, the differential voltage signal output by the strain gauge in the Wheatstone bridge is acquired.

[0099] In the technical solution provided in step S701 of this application, the Wheatstone bridge is used to form a strain gauge sensor module, and the differential voltage signal is used to characterize the measured load of the vehicle.

[0100] In this embodiment, when the strain gauge sensor module is in DC excitation power supply mode and the vehicle's weighing system enters the load measurement phase, the control module (MCU) activates the DC excitation power supply to periodically power the Wheatstone bridge. This Wheatstone bridge consists of four resistors, with at least one arm being a strain gauge attached to the vehicle frame or leaf spring elastomer, and the remaining arms being matching resistors, forming a symmetrical balanced resistor network. Under vehicle load, the elastomer deforms, causing a slight change in the strain gauge resistance, disrupting the bridge's original balance and generating a differential voltage signal proportional to the load between the two output terminals of the Wheatstone bridge.

[0101] Optionally, the aforementioned differential voltage signal has an extremely small amplitude (typically in the millivolt range) and is easily affected by environmental interference. Therefore, it needs to be extracted and amplified by a high-precision differential amplifier circuit. This amplifier circuit is directly connected to a Wheatstone bridge and is responsible for converting the weak differential signal into a voltage level that can be accurately sampled by the subsequent analog-to-digital converter. The acquisition process is only performed in DC excitation power supply mode, and this power supply is applied for a short time in a pulsed manner. That is, the circuit between the DC excitation power supply and the strain gauge sensor module is turned on at the beginning of each working cycle (e.g., 100ms), and then turned off at the rest of the time to suppress self-heating. In this way, real-time response to changes in vehicle load is ensured, and the temperature rise of the strain gauge itself caused by continuous power supply is effectively avoided, reducing the impact of thermal drift on measurement accuracy from the source.

[0102] Step S702: In response to the strain gauge sensor module being in constant current source power supply mode, determine the temperature signal of the strain gauge.

[0103] In the technical solution provided in step S702 of this application, after completing one load measurement, the temperature self-test stage begins. At this time, the control module switches the power supply mode of the strain gauge sensor from DC excitation power supply mode to constant current source power supply mode. In constant current source power supply mode, a constant current is injected into the strain gauge sensor module through a low-power, high-stability constant current source. At this time, the Wheatstone bridge in the strain gauge sensor module no longer bears the external load, and the change in its total resistance is dominated only by the temperature characteristics of the material itself.

[0104] In this embodiment, when the strain gauge sensor module is in constant current source power supply mode, the constant current source drives the current through the closed resistor network formed by the strain gauges and bridge arm resistors in the strain gauge sensor module, generating a voltage signal proportional to the total resistance across the Wheatstone bridge. This voltage signal is buffered and amplified by a high input impedance operational amplifier circuit before being sent to the signal processing unit. Using the known constant current value and the acquired voltage value, the total resistance of the bridge under the current environment can be accurately calculated. This is because the strain gauge material (e.g., constantan) has a well-defined and stable temperature coefficient of resistance (e.g., 1.9 × 10⁻⁶). - (³ / ℃), combined with the reference resistance value calibrated at the factory at a standard temperature (e.g., 25℃), and based on the linear relationship between resistance and temperature, the temperature signal of the strain gauge itself can be calculated in real time.

[0105] Optionally, the aforementioned temperature signal does not originate from an external sensor, but rather directly from the physical properties of the strain gauge material itself. This achieves temperature sensing from the same point, source, and material, eliminating measurement errors caused by installation misalignment, thermal conduction lag, or environmental gradients in traditional external temperature sensors. This step is a crucial prerequisite for achieving automatic zeroing across the entire temperature range. The output temperature signal will be directly used for zero-point compensation and gain correction in the next cycle, enabling the weighing system to possess adaptive, self-learning, and intelligent characteristics that require no manual calibration.

[0106] Step S703: The differential voltage signal is calibrated based on the temperature signal to obtain the calibrated differential voltage signal.

[0107] In the technical solution provided in step S703 of this application, after acquiring the real-time temperature signal of the strain gauge, a dynamic calibration stage can be entered. The temperature signal is used to compensate and correct the differential voltage signal acquired in the previous cycle, thereby eliminating the zero-point drift and sensitivity change caused by temperature, and outputting a high-precision calibrated differential voltage signal.

[0108] In this embodiment, because the temperature coefficient of resistance of the strain gauge material and the thermal expansion characteristics of the elastomer will systematically shift with temperature changes, the output voltage of the bridge will also shift (zero-point drift) even under no-load conditions; at the same time, the sensitivity of the strain gauge (the voltage change per unit strain) will also increase or decrease with temperature changes (gain drift). Therefore, the required zero-point shift compensation and gain adjustment coefficient at the current temperature are automatically calculated by using the temperature compensation mapping relationship pre-stored in the control module.

[0109] For example, based on the temperature signal, the compensation voltage value to be applied to the reference terminal of the differential amplifier circuit is calculated by looking up a table or through a linear model, and this compensation voltage value is output through a digital-to-analog converter to actively cancel zero-point drift. At the same time, by adjusting the variable resistor network, the closed-loop gain of the amplifier is dynamically adjusted to compensate for the sensitivity change caused by temperature. This compensation process is not a static table lookup, but is based on the accurate strain gauge body temperature obtained in the previous temperature self-test stage, and is calculated and dynamically updated in real time to achieve true closed-loop adaptive calibration.

[0110] Optionally, the calibrated differential voltage signal, having eliminated temperature interference, accurately reflects the mechanical strain caused by vehicle load, with an accuracy far exceeding that of traditional indirect compensation methods using external temperature sensors. This step tightly couples temperature sensing with signal calibration, forming a complete closed loop of "temperature measurement—calculation—compensation—re-measurement," enabling the system to maintain stable and accurate weighing performance across a wide temperature range. It eliminates the need for manual calibration after delivery and requires no maintenance calibration, achieving a technological leap from "passive compensation" to "active intelligent calibration" in vehicle-mounted weighing systems.

[0111] Step S704: Using the voltage load mapping relationship, the calibrated differential voltage signal is mapped to obtain the target load signal of the vehicle.

[0112] In the technical solution provided by step S704 of this application, the target load signal is used to characterize the actual load of the vehicle, and the voltage load mapping relationship is used to represent the mapping relationship between different differential voltage signals and different load signals of the vehicle.

[0113] In this embodiment, after temperature adaptive calibration is completed, the compensated differential voltage signal is input into a preset voltage load mapping model to output the final target load signal. This mapping relationship is essentially established through the system calibration process, reflecting the functional correspondence between the bridge output voltage and the actual applied load under specific structural, material, and installation conditions. This mapping relationship is typically acquired and fitted at multiple known load points (such as no-load, rated load, and overload) during the vehicle assembly stage to form a calibration curve based on a linear or polynomial model. Alternatively, it can be stored in the control unit using a piecewise lookup table method.

[0114] Optionally, since dynamic compensation for zero-point drift and sensitivity drift has been achieved through temperature self-testing in the previous steps, the differential voltage signal input to the mapping model has now been freed from temperature interference, exhibiting high consistency and stability. Therefore, the mapping process does not require frequent recalibration and maintains high accuracy across the entire temperature range. Simply substituting the calibrated differential voltage signal into this fixed mapping relationship allows direct calculation of the vehicle's current actual load value, which is the target load signal, accurately reflecting the physical weight of the cargo or load.

[0115] In this step, the voltage-load mapping relationship only needs to be calibrated once during installation or at the factory. Subsequent operation relies entirely on the temperature self-calibration mechanism to maintain its effectiveness, greatly reducing maintenance costs and the barrier to entry. Simultaneously, because the signal has already achieved high-fidelity acquisition with "same point, same source, and no thermal interference" before entering the mapping stage, the accuracy of the mapping result is far higher than that of traditional systems using external temperature compensation or fixed coefficient correction. The target load signal, as the final output, can be directly used for applications such as vehicle monitoring, overload warning, and logistics scheduling, making it the core output component for achieving "high precision, maintenance-free, all-weather" vehicle weighing.

[0116] In steps S701 to S704 of this application, the strain gauge sensor module achieves coordinated measurement of differential voltage and temperature signals through a time-division multiplexing power supply mode. Specifically, when the strain gauge sensor module is powered by a DC excitation power supply, it acquires the differential voltage signal output by the strain gauge; when powered by a constant current source, it acquires the temperature signal of the strain gauge. This time-division multiplexing method allows the acquisition of the strain gauge temperature signal without the need for an external temperature sensor. Subsequently, the differential voltage signal is calibrated using the strain gauge temperature signal to compensate for the interference caused by resistance drift due to temperature changes. Finally, the calibrated differential voltage signal is mapped using the voltage-load mapping relationship to obtain the target load signal of the vehicle. In other words, by using the time-division multiplexing of the same strain gauge, temperature and load can be simultaneously and synchronously sensed from the same source, at the same point, without the need for an external temperature sensor, significantly improving the weighing accuracy of the vehicle and thus solving the technical problem of low vehicle weighing accuracy in related technologies.

[0117] As an optional implementation, step S702, in response to the strain gauge sensor module being in constant current source power supply mode, determines the temperature signal of the strain gauge, including: in response to the strain gauge sensor module being in constant current source power supply mode, measuring the resistance value of the strain gauge; inputting the resistance value into a linear temperature model to determine the temperature signal of the strain gauge, wherein the linear temperature model is used to characterize the linear dependence between the resistance value of the strain gauge and the temperature signal.

[0118] In this embodiment, during the temperature self-testing phase, the connection between the DC excitation power supply and the strain gauge sensor module is completely disconnected. The strain gauge sensor module is powered by a constant current source. Under these conditions, there is no external load acting on the Wheatstone bridge in the strain gauge sensor module, and the strain gauge no longer experiences resistance changes due to deformation; its resistance fluctuations are dominated solely by temperature changes. Under these conditions, a stable current is injected into the Wheatstone bridge in the strain gauge sensor module through a constant current source, and the voltage response across the entire Wheatstone bridge circuit is measured. Combined with the known constant current value, the total equivalent resistance of the Wheatstone bridge is accurately calculated. Since the strain gauge, as a key sensitive element in the bridge structure, has its resistance change dominating the total resistance change, this total resistance effectively reflects the real-time resistance state of the strain gauge itself.

[0119] Optionally, to convert the total equivalent resistance of the Wheatstone bridge into a temperature signal, a preset linear temperature model is used. This model is based on the inherent temperature characteristics of the strain gauge material (e.g., constantan), and its mathematical expression is: Temperature T = 25 + [R_bridge(T) - R0] / α·R0, where R0 is the reference resistance calibrated at the calibration reference temperature (usually 25℃), R_bridge(T) is the currently measured resistance value, and α is the temperature coefficient of resistance of the material (typically approximately 1.9 × 10⁻⁶). - (³ / ℃). This model was obtained during the factory calibration stage by measuring the resistance values ​​of strain gauges at multiple temperature points under constant temperature conditions, and its linearity and stability were verified through linear fitting.

[0120] Optionally, this linear temperature model allows for the direct calculation of the strain gauge's true temperature from a single resistance measurement without relying on external sensors, achieving high-precision sensing with "same-point temperature measurement, no positional error, and no thermal interference." The acquisition of this temperature signal relies entirely on the strain gauge's own physical properties, representing the core technological path to a "sensorless" solution. This step not only simplifies the system hardware architecture and reduces wiring complexity and failure rate, but also fundamentally solves the compensation deviation problem caused by the separation of temperature and force measurement points in traditional solutions, providing a true, reliable, and high-precision temperature input basis for subsequent automatic calibration.

[0121] According to an embodiment of this application, a vehicle weighing device is also provided. It should be noted that this vehicle weighing device can be used to perform the vehicle weighing method described in the embodiments.

[0122] Figure 8 This is a schematic diagram of a vehicle weighing device according to an embodiment of this application. Figure 8 As shown, the weighing device 800 of the vehicle may include: a data acquisition unit 801, a determination unit 802, a calibration unit 803, and a mapping unit 804.

[0123] The acquisition unit 801 is used to acquire the differential voltage signal output by the strain gauge in the Wheatstone bridge in response to the strain gauge sensor module being in DC excitation power supply mode. The Wheatstone bridge is used to form the strain gauge sensor module, and the differential voltage signal is used to characterize the measured load of the vehicle.

[0124] The determination unit 802 is used to determine the temperature signal of the strain gauge in response to the strain gauge sensor module being in constant current source power supply mode.

[0125] The calibration unit 803 is used to calibrate the differential voltage signal based on the temperature signal to obtain the calibrated differential voltage signal.

[0126] The mapping unit 804 is used to map the calibrated differential voltage signal using the voltage-load mapping relationship to obtain the target load signal of the vehicle. The target load signal is used to characterize the actual load of the vehicle, and the voltage-load mapping relationship is used to represent the mapping relationship between different differential voltage signals and different load signals of the vehicle.

[0127] Optionally, the determining unit 802 is further configured to: measure the resistance value of the strain gauge in response to the strain gauge sensor module being in constant current source power supply mode; input the resistance value into a linear temperature model to determine the temperature signal of the strain gauge, wherein the linear temperature model is used to characterize the linear dependence between the resistance value of the strain gauge and the temperature signal.

[0128] In the aforementioned vehicle weighing device, the strain gauge sensor module achieves coordinated measurement of differential voltage and temperature signals through a time-division multiplexing power supply mode. Specifically, when the strain gauge sensor module is powered by a DC excitation power supply, it acquires the differential voltage signal output by the strain gauge; when powered by a constant current source, it acquires the temperature signal. This time-division multiplexing method allows acquisition of the strain gauge temperature signal without the need for an external temperature sensor. Subsequently, the differential voltage signal is calibrated using the strain gauge temperature signal to compensate for interference caused by resistance drift due to temperature changes. Finally, the calibrated differential voltage signal is mapped using a voltage-load mapping relationship to obtain the vehicle's target load signal. In other words, by using the same strain gauge for time-division multiplexing, temperature and load can be sensed synchronously from the same source and point without an external temperature sensor, significantly improving vehicle weighing accuracy and thus solving the technical problem of low vehicle weighing accuracy in related technologies.

[0129] Embodiments of this application also provide a vehicle, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the weighing method of the vehicle in various embodiments of this application when it runs.

[0130] Embodiments of this application also provide an electronic device, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the vehicle weighing method of various embodiments of this application when it runs.

[0131] Embodiments of this application also provide a computer-readable storage medium including a stored executable program, wherein, when the executable program is executed, it controls the device where the computer-readable storage medium is located to perform the vehicle weighing method of various embodiments of this application.

[0132] Embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the vehicle weighing method of various embodiments of this application.

[0133] Embodiments of this application also provide a computer program product, including a non-volatile computer-readable storage medium for storing a computer program that, when executed by a processor, implements the vehicle weighing method in various embodiments of this application.

[0134] Embodiments of this application also provide a computer program that, when executed by a processor, implements the vehicle weighing methods described in the various embodiments of this application.

[0135] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0136] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0137] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0138] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0139] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0140] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0141] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A vehicle weighing system, characterized in that, include: The strain gauge sensor module is composed of a Wheatstone bridge, wherein the Wheatstone bridge includes at least one strain gauge, the strain gauge being used to output a differential voltage signal when the strain gauge sensor module is in DC excitation power supply mode, the differential voltage signal being used to characterize the measured load of the vehicle; A temperature determination module, connected to the strain gauge sensor module, is used to determine the temperature signal of the strain gauge when the strain gauge sensor module is in constant current source power supply mode; The strain signal processing module is connected to the strain gauge sensor module and the temperature determination module respectively, and is used to calibrate the differential voltage signal based on the temperature signal to obtain the calibrated differential voltage signal. The control module, connected to the strain signal processing module, is used to map the calibrated differential voltage signal using a voltage-load mapping relationship to obtain the target load signal of the vehicle. The target load signal is used to characterize the actual load of the vehicle, and the voltage-load mapping relationship is used to represent the mapping relationship between different differential voltage signals and different load signals of the vehicle.

2. The system according to claim 1, characterized in that, The system also includes: A strain gauge excitation switch module is connected to the strain gauge sensor module and is used to control the strain gauge sensor module to operate in the DC excitation power supply mode or exit the DC excitation power supply mode.

3. The system according to claim 2, characterized in that, The control module is also connected to the strain gauge excitation switch module and is used to output a first timing control signal or a second timing control signal to the strain gauge excitation switch module. The first timing control signal is used to turn on the voltage transmission circuit between the DC excitation power supply and the strain gauge sensor module so that the strain gauge sensor module can operate in the DC excitation power supply mode. The second timing control signal is used to turn off the voltage transmission circuit between the DC excitation power supply and the strain gauge sensor module so that the strain gauge sensor module can exit the DC excitation power supply mode.

4. The system according to claim 1, characterized in that, The control module is also connected to the temperature determination module and is used to output a third timing control signal or a fourth timing control signal to the temperature determination module. The third timing control signal is used to turn on the voltage transmission circuit between the constant current source and the strain gauge sensor module so that the strain gauge sensor module operates in the constant current source power supply mode. The fourth timing control signal is used to turn off the voltage transmission circuit between the constant current source and the strain gauge sensor module so that the strain gauge sensor module exits the constant current source power supply mode.

5. The system according to claim 4, characterized in that, The temperature determination module includes: The constant current source is used to output a constant current; A switch control unit is used to turn on the voltage transmission circuit between the constant current source and the strain gauge sensor module under the action of the third timing control signal, or to turn off the voltage transmission circuit between the constant current source and the strain gauge sensor module under the action of the fourth timing control signal. The signal acquisition and amplification unit is used to measure the resistance value of the strain gauge when the voltage transmission circuit between the constant current source and the strain gauge sensor module is turned on, and to determine the temperature signal of the strain gauge based on the resistance value and a linear temperature model, wherein the linear temperature model is used to characterize the linear dependence between the resistance value of the strain gauge and the temperature signal.

6. The system according to claim 1, characterized in that, The strain signal processing module includes: A differential amplifier unit is used to receive the differential voltage signal and amplify the differential voltage signal to obtain the amplified differential voltage signal. A digital-to-analog converter is used to output a zero-point compensation voltage that matches the current temperature of the vehicle. The zero-point compensation voltage serves as a reference voltage for the differential amplifier unit and is used to calibrate the zero-point drift voltage caused by temperature changes in the amplified differential voltage signal. The value of the zero-point compensation voltage is equal to and has the same polarity as the zero-point drift voltage. The resistor unit is used to adjust the amplification factor of the differential amplifier unit for amplifying the differential voltage signal.

7. A method for weighing a vehicle, characterized in that, The weighing system applied to the vehicle according to any one of claims 1 to 6, comprising: In response to the strain gauge sensor module being in DC excitation power supply mode, the differential voltage signal output by the strain gauge in the Wheatstone bridge is acquired, wherein the Wheatstone bridge is used to construct the strain gauge sensor module, and the differential voltage signal is used to characterize the measured load of the vehicle. In response to the strain gauge sensor module being in constant current source power supply mode, the temperature signal of the strain gauge is determined; The differential voltage signal is calibrated based on the temperature signal to obtain the calibrated differential voltage signal; The voltage-load mapping relationship is used to map the calibrated differential voltage signal to obtain the target load signal of the vehicle. The target load signal is used to characterize the actual load of the vehicle, and the voltage-load mapping relationship is used to represent the mapping relationship between different differential voltage signals and different load signals of the vehicle.

8. The method according to claim 7, characterized in that, In response to the strain gauge sensor module being in constant current source power supply mode, the temperature signal of the strain gauge is determined, including: In response to the strain gauge sensor module being in the constant current source power supply mode, the resistance value of the strain gauge is measured; The resistance value is input into a linear temperature model to determine the temperature signal of the strain gauge, wherein the linear temperature model is used to characterize the linear dependence between the resistance value of the strain gauge and the temperature signal.

9. A vehicle, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 7 to 8.

10. An electronic device, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 7 to 8.

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