Vehicle weight measurement method and system based on MEMS attitude sensor

Abstract

The present invention discloses a vehicle weight measurement method based on a MEMS attitude sensor, which includes the following steps: installing a first MEMS attitude sensor and a second MEMS attitude sensor; using the measurement data of the second MEMS attitude sensor to perform roll compensation and pitch compensation on the measurement data of the first MEMS attitude sensor; calculating the actual load of each spring steel plate and calculating the total weight of the vehicle. During measurement, the method uses a plurality of first MEMS attitude sensors to be fixedly connected to the spring steel plates supported by each wheel to obtain an initial attitude. A second MEMS attitude sensor is fixedly connected to the cross beam of the vehicle, and the second MEMS attitude sensor is always the same as the vehicle attitude. When the vehicle encounters ups and downslopes or uneven roads, the measured attitude data output by the second MEMS attitude sensor is compared with the measured data output by the sensors at the spring steel plates supporting other wheels to perform roll compensation, eliminate the influence of such vehicles on the measurement under uneven road conditions, and ensure the accuracy of the measurement data.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle-mounted self-test technology, and in particular to a vehicle weight measurement method based on a MEMS attitude sensor and a system thereof. Background Art

[0002] At present, vehicle traffic accidents and road and bridge damage accidents occur frequently, and vehicle overloading is one of the main factors that cause many accidents. Therefore, it is very meaningful to measure the weight of the vehicle, which can monitor the vehicle at any time through the changes in the vehicle weight to ensure the safety of the vehicle's operation.

[0003] Currently, most existing weight measurement methods measure vehicle weight through strain gauges, infrared ranging, ultrasonic radar, etc., but these measuring devices are complicated to install, and some devices will damage the structure of the vehicle body during installation. In addition, the measurement accuracy is low and cannot meet the monitoring needs. Although there are some sensors with higher measurement accuracy that can measure the weight of the vehicle more accurately, when the vehicle is driving on a slope or bumpy road, these sensors often cannot filter out the impact of acceleration and posture changes caused by the slope on the weight, and thus cannot accurately measure the vehicle weight.

[0004] In summary, the existing vehicle weight measurement devices have the disadvantages of complex installation and low measurement accuracy. Therefore, it is urgent to study a new method for measuring vehicle weight to improve the accuracy of vehicle weight measurement. Summary of the invention

[0005] In order to solve the deficiencies of the prior art, the present invention sets a mems attitude sensor, uses the pressure angle to represent the deformation of the spring steel plates that are deformed by the vehicle's load-bearing, and performs multi-attitude measurements to cope with various road conditions, thereby ensuring the validity of the output data; the mems attitude sensor is fixed on the crossbeam of the vehicle body, because the crossbeam of the vehicle body does not bear weight and therefore does not deform, thereby ensuring that the attitude output on the crossbeam is always the vehicle's own attitude. By comparing the attitude output by the spring steel plates in each load-bearing area with the vehicle attitude output by the vehicle crossbeam, the three-dimensional attitude of the vehicle output by the mems attitude sensor installed on the crossbeam can be used to perform roll compensation and pitch compensation on the spring steel plates, thereby being able to calculate the total weight of the vehicle under various road conditions and driving conditions, the measurement result has high accuracy, effectively eliminating the influence on the weight caused by the attitude change caused by acceleration and ramps, and being able to better monitor the weight change of the vehicle.

[0006] Specifically, to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] The present invention provides a vehicle weight measurement method based on a MEMS attitude sensor, which comprises the following steps:

[0008] S1. Install the first mems attitude sensor and the second mems attitude sensor: fix the first mems attitude sensors to the supporting spring steel plates of each wheel, and fix the second mems attitude sensor to the cross beam of the vehicle;

[0009] S2. Detect the pitch angle θ of each spring steel plate i , roll angle γ i And heading angle ψ: Use multiple first MEMS attitude sensors to detect the deformation of the spring steel plate, and output the pitch angle θ of each spring steel plate through their respective attitude changes i , roll angle γ i and the heading angle ψ;

[0010] Wherein, i refers to the i-th first MEMS attitude sensor, i=1,2,3,4,…;

[0011] S3, detect the pitch angle θ of the vehicle body m , roll angle γ m And the heading angle ψ: The second MEMS attitude sensor detects the vehicle's driving condition and outputs the vehicle's pitch angle θ m , roll angle γ m and the heading angle ψ;

[0012] S4. Calculate the roll compensation angle Δγ i : The roll angle γ of each spring steel plate output by multiple first MEMS attitude sensors i and the vehicle body roll angle γ m Calculate the roll compensation angle Δγ i , roll compensation is performed on multiple spring steel plates respectively, and the roll compensation angle Δγ i The calculation formula is:

[0013] Δγ i =γ i -γ m (1);

[0014] S5. Calculate the pitch compensation angle Δθ i : The pitch angle θ of each spring steel plate output by each first MEMS attitude sensor i and the vehicle pitch angle θ m Calculate the pitch compensation angle Δθ i , perform pitch compensation on multiple spring steel plates respectively, and the pitch compensation angle Δθ i The calculation formula is:

[0015] Δθ i =θ i -θ m (2);

[0016] S6. Calculate the load Δq of the spring steel plate i :The relationship between the deflection of the spring steel plate and its load is linearized to obtain the proportional coefficient k. The spring steel plate is simplified into a simply supported beam. The load Δq of the spring steel plate is calculated based on the pitch compensation angle using the following formula: i :

[0017]

[0018] Where, E is the elastic modulus, I is the section moment of inertia, and l is the length;

[0019] S7. Calculate the actual load q of the spring steel plate i : According to the roll compensation angle Δγ i The spring steel plate is subjected to force correction and the actual load q of the spring steel plate is calculated using the following formula: i :

[0020]

[0021] S8. Calculate the total vehicle weight q: Calculate the actual load q of each spring steel plate in sequence according to step S6 and step S7. i , and calculate the total vehicle weight q according to formula (5):

[0022] q=q1+q2+…+q i (5);

[0023] Among them, q1, q2, …q i The actual loads of the 1st, 2nd, ..., ith spring steel plates are

[0024] Preferably, the difference between the heading angle output by the second mems attitude sensor and the heading angle output by a first mems attitude sensor is calculated, and when the difference between the two is greater than a difference threshold, it is determined that the first mems attitude sensor or the second mems attitude sensor is faulty.

[0025] Preferably, the first mems attitude sensor and the second mems attitude sensor include a three-axis gyroscope, a three-axis accelerometer and a three-axis electronic compass motion sensor.

[0026] Preferably, in step S1, a plurality of first MEMS attitude sensors are respectively installed in different areas of the vehicle.

[0027] Preferably, in step S6, the relationship between the deflection of the spring steel plate and its load is linearized to obtain the proportional coefficient k in the following specific steps:

[0028] Each time a load ΔP is applied to the leaf spring i = 200kg, perform n calibrations, take the spring steel plate deflection as the horizontal axis and mark it as w i, the load is longitudinal and marked as P i , we get the point set (w i , P i )(i=1, 2, 3, ···, 51), after curve fitting, the load and deflection curve of the spring steel plate is obtained.

[0029] Preferably, a plurality of first mems attitude sensors are installed on each spring steel plate or a plurality of first mems attitude sensors are installed in a load-bearing area.

[0030] Another aspect of the present invention also provides a measurement system for the above-mentioned vehicle weight measurement method based on MEMS attitude sensors, which includes multiple first MEMS attitude sensors and second MEMS attitude sensors, wherein the multiple first MEMS attitude sensors are fixedly connected to the supporting spring steel plates of each wheel or the load-bearing area of ​​the vehicle body, and the second MEMS attitude sensors are fixedly connected to the vehicle cross beam.

[0031] Preferably, the plurality of first mems attitude sensors and the second mems attitude sensors have the same structure, and both include a three-axis gyroscope, a three-axis accelerometer and a three-axis electronic compass motion sensor.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention can monitor the posture and weight of the vehicle in real time by arranging the MEMS posture sensor at different positions on the vehicle. The MEMS posture sensor contains auxiliary motion sensors such as a three-axis gyroscope, a three-axis accelerometer and a three-axis electronic compass, so that all six degrees of freedom can be measured and the high-precision three-dimensional posture of the vehicle support spring steel plate can be output, which helps to improve the measurement accuracy of the entire method.

[0034] (2) The present invention outputs high-precision three-dimensional vehicle posture by installing MEMS posture sensors on the vehicle crossbeam and the load-bearing supporting spring steel plates. When the vehicle goes uphill or downhill or the road is uneven, the three-dimensional posture output on each supporting spring steel plate is compared and calculated with the three-dimensional vehicle posture output by the sensor on the crossbeam, so as to perform roll compensation and pitch compensation for the spring steel plate, which can effectively offset the influence of acceleration and posture changes in all directions caused by changes in vehicle posture and bumps in the vehicle body during driving, thereby being able to measure the vehicle weight with high precision under various road conditions and ensure the accuracy of the final vehicle weight measurement. It can be especially applied to the measurement of the weight of a moving truck to ensure the accuracy of the truck weight measurement.

[0035] (3) The number of MEMS posture sensors used in this method can be adjusted according to the length of the vehicle, or divided according to the load-bearing area. Different schemes can be selected according to different vehicle models. Specifically, the first MEMS posture sensor can be installed on each spring steel plate or in a load-bearing area, and the weight change can be calculated by the change in posture position.

[0036] (4) During operation, the present invention can compare the heading angle output by the first MEMS attitude sensor at the crossbeam with the heading angle output by the sensor at the spring steel plate. When a large deviation occurs between the heading angles output by the two, it can be used as a basis for determining that the MEMS attitude sensor has failed, thereby timely replacing or reinstalling the MEMS attitude sensor, thereby ensuring the accuracy of the final measurement result and avoiding the influence of the final measurement result on the accuracy and precision of the measurement result due to the wrong sensor placement position or the sensor's own failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the process of the present invention;

[0038] Figure 2 It is a schematic diagram of the detection principle of the present invention;

[0039] Figure 3 It is a schematic diagram of the present invention for roll compensation;

[0040] Figure 4 It is a schematic diagram of the linearization of the load-deflection curve according to the present invention. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following examples are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0042] First, on the one hand, the present invention provides a vehicle weight measurement system, which can be used in particular for measuring the weight of a moving truck, filtering out the influence of interference factors and ensuring the accuracy of the truck load measurement. Figure 2 As shown, it includes a plurality of first mems attitude sensors 2, 4 and 8 and a second mems attitude sensor 7 which are dispersedly installed. The plurality of first mems attitude sensors 2, 4 and 8 are respectively fixedly connected to the supporting spring steel plates of each wheel or the load-bearing area of ​​the vehicle body, and a second mems attitude sensor is fixedly connected to the vehicle cross beam. The fixing device can be a fixed connecting member such as bolts. The vehicle cross beam itself is not subjected to force and therefore will not deform. The second mems attitude sensor can detect the shape of the vehicle, that is, the driving condition of the vehicle. The output ends of the first mems attitude sensor and the second mems attitude sensor are both connected to the controller, and the subsequent calculation process is completed by the controller.

[0043] In terms of specific structure, the structures of the multiple first mems attitude sensors and the second mems attitude sensors are the same, including a three-axis gyroscope, a three-axis accelerometer and a three-axis electronic compass motion sensor. Due to the different installation positions and functions, their names are distinguished. The mems attitude sensor installed in the load-bearing area is called the first mems attitude sensor, and the mems attitude sensor installed at the crossbeam position is called the second mems attitude sensor.

[0044] On the other hand, the present invention proposes a vehicle weight measurement method based on a MEMS attitude sensor, such as Figure 1 As shown, it includes the following steps:

[0045] S1. Install the first mems attitude sensor and the second mems attitude sensor: fix the first mems attitude sensors to the supporting spring steel plates of each wheel, and fix the second mems attitude sensor to the cross beam of the vehicle;

[0046] S2. Detect the pitch angle θ of each spring steel plate i , roll angle γ i And heading angle ψ: Use multiple first MEMS attitude sensors to detect the deformation of the spring steel plate, and output the pitch angle θ of each spring steel plate through their respective attitude changes i , roll angle γ i and the heading angle ψ;

[0047] Wherein, i refers to the i-th first MEMS attitude sensor, i=1,2,3,4,…;

[0048] S3, detect the pitch angle θ of the vehicle body m , roll angle γ m And the heading angle ψ: The second MEMS attitude sensor detects the vehicle's driving condition and outputs the vehicle's pitch angle θ m , roll angle γ m and the heading angle ψ;

[0049] S4. Calculate the roll compensation angle Δγ i : The roll angle γ of each spring steel plate output by multiple first MEMS attitude sensors i and the vehicle body roll angle γ m Calculate the roll compensation angle Δγ i , roll compensation is performed on multiple spring steel plates respectively, and the roll compensation angle Δγ i The calculation formula is:

[0050] Δγ i =γ i -γ m (1);

[0051] S5. Calculate the pitch compensation angle Δθ i : The pitch angle θ of each spring steel plate output by each first MEMS attitude sensor i and the vehicle pitch angle θ m Calculate the pitch compensation angle Δθ i , perform pitch compensation on multiple spring steel plates respectively, and the pitch compensation angle Δθ i The calculation formula is:

[0052] Δθ i =θ i -θ m (2);

[0053] S6. Calculate the load Δq of the spring steel plate i :The relationship between the deflection of the spring steel plate and its load is linearized to obtain the proportional coefficient k. The spring steel plate is simplified into a simply supported beam. The load Δq of the spring steel plate is calculated based on the pitch compensation angle using the following formula: i :

[0054]

[0055] Where, E is the elastic modulus, I is the section moment of inertia, and l is the length;

[0056] S7. Calculate the actual load q of the spring steel plate i : According to the roll compensation angle Δγ i The spring steel plate is subjected to force correction and the actual load q of the spring steel plate is calculated using the following formula: i :

[0057]

[0058] S8. Calculate the total vehicle weight q: Calculate the actual load q of each spring steel plate in sequence according to step S6 and step S7. i , and calculate the total vehicle weight q according to formula (5):

[0059] q=q1+q2+…+q i (5);

[0060] Among them, q1, q2, …q i are the actual loads of the 1st, 2nd, ..., ith spring steel plates respectively.

[0061] Based on the above steps, this method outputs high-precision vehicle three-dimensional posture by installing MEMS posture sensors on the vehicle crossbeam and load-bearing support spring steel plates or other load-bearing areas, so that when the vehicle goes uphill or downhill or the road is uneven, the three-dimensional posture output on each support spring steel plate is compared and calculated with the vehicle three-dimensional posture output by the sensor on the crossbeam, which can effectively offset the influence of acceleration and posture changes in all directions caused by changes in vehicle posture and bumps in the vehicle body during driving, thereby measuring vehicle weight with high precision under various road conditions, and the entire calculation method is simple and accurate.

[0062] The present invention is further described in detail below in conjunction with specific embodiments:

[0063] This embodiment proposes a truck weight measurement method based on a MEMS attitude sensor, where a plurality of first MEMS attitude sensors are dispersedly fixed on the vehicle body supporting spring steel plates. A second MEMS attitude sensor is fixed on the truck cross beam. In this embodiment, the truck has four spring steel plates, so four first MEMS attitude sensors are set. Figures 2 to 3 As shown, it uses multiple MEMS attitude sensors at different positions to output three-dimensional attitudes for comparative calculation, so as to finally obtain the weight of the truck. Specifically, it includes the following steps:

[0064] S1, such as Figure 2 As shown, first, the first MEMS attitude sensor 2 is fixedly connected to the spring steel plate 1 supported by the vehicle body, and the pitch angle θ1 is output; the first MEMS attitude sensor 4 is fixedly connected to the spring steel plate 3, and the pitch angle θ2 is output; the first MEMS attitude sensor is fixedly connected to the spring steel plate 5, and the pitch angle θ3 is output; the first MEMS attitude sensor 8 is fixedly connected to the spring steel plate 9, and the pitch angle θ4 is output; then the second MEMS attitude sensor 7 is fixedly connected to the truck beam, and the roll angle γ is output. m and the pitch angle θ m .

[0065] S2, using a second MEMS attitude sensor 7 output pitch angle θ m That is, the driving posture of the truck, which can be used to compensate for the pressure angle posture output by the sensor on the spring steel plate, ensuring that the output pressure angle is only caused by the deformation of the spring due to load, and does not include other reasons, thereby filtering out the impact of posture changes on the vehicle during driving.

[0066] S3. According to the scheme in step S1, each first MEMS attitude sensor is fixedly connected to the corresponding supporting spring steel plate of each wheel shown in the figure by bolts or other connecting parts, and a second MEMS attitude sensor 7 is fixedly connected to the vehicle cross beam by bolts or other connecting parts.

[0067] S4, when the vehicle is driving, the first MEMS attitude sensor installed on each wheel support spring steel works to detect the deformation of the support spring steel plate, and outputs the actual measured pitch angles θ through its own attitude change. i (i=1,2,3,4,…), roll angle γ i (i=1,2,3,4,…) and heading angle ψ.

[0068] S5: The second MEMS attitude sensor fixedly connected to the vehicle cross beam outputs the vehicle pitch angle θ according to the measured vehicle driving condition. m Roll angle γ m and the heading angle ψ.

[0069] S6, the second MEMS attitude sensor fixedly connected to the crossbeam measures the vehicle attitude and outputs the roll angle γ m , the first MEMS attitude sensor fixedly connected to the other spring steel plate is subjected to roll compensation. Roll compensation angle Δγ i (i=1,2,3,4,…) The calculation formula is:

[0070] Δγ i =γ i -γ m

[0071] The pitch angle θ output by the second MEMS attitude sensor on each wheel support spring steel plate i (i=1,2,3,4,…) are respectively related to the pitch angle θ output by the first MEMS attitude sensor on the beam m By comparison, we can get the pitch compensation angle Δθ i , which is used as the main parameter for calculating vehicle weight. Pitch compensation angle Δθ i The calculation formula is:

[0072] Δθ i =θ i -θ m .

[0073] In addition, in specific work, if under normal circumstances, the heading angle output by the first MEMS attitude sensor at the crossbeam is basically the same as the heading angle output by the sensor at the spring steel plate within a certain range, therefore, the two can be compared during the work process. When there is a large deviation in the heading angle output by the two, it can be used as a basis for judging the failure of the MEMS attitude sensor. In this case, the arranged MEMS attitude sensor should be replaced or reinstalled until the heading angle output by the first MEMS attitude sensor at the crossbeam is basically the same as the heading angle output by the sensor at the spring steel plate within a certain range, and it is presumed that the result is accurate at this time. In specific work, the working status of the sensor can be monitored in real time according to this parameter to ensure that the measurement result is accurate.

[0074] In actual working process, the relationship between the deflection of spring steel plate and its load can be linearized to obtain the proportional coefficient k. The specific steps are as follows: Each time a load ΔP is applied to the steel leaf spring i = 200kg, 51 calibrations are performed, and the deflection of the spring steel plate is taken as the horizontal axis and marked as w i , the load is longitudinal and marked as P i , we get the point set (w i , P i )(i=1,2,3,···,51), after curve fitting, the load-deflection curve of the spring steel plate is obtained. The load-deflection curve is as follows: Figure 4 shown.

[0075] After that, the spring steel plate is simplified into a simply supported beam, and the pitch compensation angle and load Δq are i The following relationship exists:

[0076]

[0077] Among them, E is the elastic modulus, I is the section moment of inertia, and l is the length.

[0078] According to the roll compensation angle Δγ i Correct the spring steel plate and get its actual load q i , the calculation formula is:

[0079]

[0080] According to formula (3) and formula (4), the force q of each spring steel plate is calculated i , then the total weight of the vehicle is q, and the calculation formula is:

[0081] q=q1+q2+…+q i

[0082] Among them, q1, q2, …q iare the actual loads of the 1st, 2nd, ..., ith spring steel plates, respectively. In this embodiment, the load Δq of each spring steel plate is first calculated according to formula (3): i Then, the actual load of each spring steel plate is calculated according to formula (4), and finally the actual loads of the four spring steel plates are added together to obtain the accurate total weight of the truck.

[0083] like Figure 2 As shown in the figure, when a truck is driving on an uneven road, its various parts bear different loads. The first MEMS attitude sensor fixedly connected to the spring steel plate outputs different roll angles due to the different loads of the spring steel plate, and the uneven road will also have a certain impact on its output of three-dimensional attitude. Therefore, the second MEMS attitude sensor on the vehicle beam is required to output the three-dimensional attitude of the vehicle as compensation, so as to obtain the pitch angle generated by the first MEMS attitude sensor at each spring steel plate to the spring steel plate due to the deformation of the load.

[0084] like Figure 3 As shown, the MEMS attitude sensor can output three-dimensional attitude. The second MEMS attitude sensor fixedly connected to the crossbeam can compensate for the output value of the attitude sensor at the spring steel plate caused by the vehicle's driving attitude in all six degrees of freedom directions when calculating the load, making the measurement result more accurate.

[0085] In practical applications, this method can not only measure the weight of the truck, but also calculate the load on the supporting spring steel plate of each wheel according to the three-dimensional posture output by the first MEMS posture of each wheel spring steel plate. It has certain guiding significance for the road driving safety of the vehicle, and can ensure the accuracy of the load on the supporting spring steel plate of each wheel and the measured vehicle weight, especially the accurate measurement of the load of the truck. The overall method is simple, the measurement result is accurate, and it is suitable for various models and scenarios.

[0086] The MEMS attitude sensor used in this method contains auxiliary motion sensors such as a three-axis gyroscope, a three-axis accelerometer and a three-axis electronic compass, and has an embedded low-power processor, high data processing efficiency and accurate results.

[0087] The three-axis gyroscope is the core sensitive device of the inertial system. Its measurement accuracy is the key to ensure attitude solution. When entering a turn or encountering a ramp, the three-axis gyroscope can give the change of attitude. The three-axis gyroscope used is highly reliable, a fully solid-state device, with no internal rotating parts, can withstand large load impacts, has a long working life, low power consumption, is easy to digitize and intelligentize, can be digitally output, temperature compensated, can fully adapt to the vehicle's working environment, and supports zero-position correction. The three-axis gyroscope uses a high-precision gyroscope to ensure the accuracy of the output attitude of the vehicle and wheel support spring steel plate, thereby ensuring that the weight of the vehicle is obtained through changes in attitude.

[0088] The three-axis accelerometer works based on the basic principle of acceleration. The three-axis accelerometer contained in the MEMS attitude sensor used in this method has the characteristics of small size, light weight, low cost, and no influence on the mechanical structure of the object being measured.

[0089] In complex road conditions, vehicles are not stable. When the road is uneven or there are many gravels, the vehicle usually bears forces in multiple directions, which will cause a certain acceleration when shaking. At the same time, due to the vehicle's own reasons, such as engine shaking or different driving habits of different drivers, dynamic loads in a certain direction will be applied to the vehicle. The acceleration sensor contained in the MEMS attitude sensor can detect the acceleration signal without knowing the direction of vehicle movement in advance. Through the acceleration compensation dynamic disturbance method, the influence of dynamic load can be eliminated when the attitude is finally measured, ensuring the accuracy of the final measurement result.

[0090] In the specific application process, the MEMS attitude sensors are installed in different positions of the vehicle to play different roles.

[0091] The MEMS attitude sensor installed at the wheel supporting the spring steel plate mainly outputs the attitude of the spring steel plate. However, due to the unevenness of some road conditions, the loads of each spring steel plate are different, which makes their deformations different. Finally, the attitude output by each MEMS attitude sensor will be affected by the vehicle attitude. Therefore, in order to accurately measure, it is necessary to install MEMS attitude sensors on the supporting spring steel plates. MEMS attitude sensors can also be installed according to the actual load area.

[0092] Only one MEMS attitude sensor is needed to be fixedly connected to the cross beam of the vehicle, because the sensor is mainly used to measure the three-dimensional attitude of the vehicle. It is only necessary to ensure that the installation position of the attitude sensor is a non-load-bearing area and no deformation occurs, so as to ensure that the three-dimensional attitude output by the attitude sensor is the same as the actual three-dimensional attitude of the vehicle.

[0093] In order to measure the vehicle weight in real time during driving, it is necessary to compare the three-dimensional posture output of each load area with the three-dimensional posture of the vehicle to ensure that the output posture of each support spring is due to the change in load-bearing and the influence of the change in vehicle posture is removed. By further calculating the load, multiple loads are added together to obtain the actual weight of the vehicle.

[0094] In the remaining embodiments of the present invention, different solutions can also be selected according to the load-bearing area division according to different vehicle models. Specifically, a MEMS attitude sensor can be installed on each spring steel plate or a MEMS attitude sensor can be installed in a load-bearing area. Different solutions can be selected according to different vehicles to achieve the measurement of the actual weight of each vehicle and ensure the accuracy of the measurement results.

[0095] The embodiments described above are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A vehicle weight measurement method based on a MEMS attitude sensor, characterized in that: It includes the following steps: S1. Install the first mems attitude sensor and the second mems attitude sensor: fix the first mems attitude sensors to the supporting spring steel plates of each wheel, and fix the second mems attitude sensor to the cross beam of the vehicle; S2. Detect the pitch angle θ of each spring steel plate i , roll angle γ i And heading angle ψ: Use multiple first MEMS attitude sensors to detect the deformation of the spring steel plate, and output the pitch angle θ of each spring steel plate through their respective attitude changes i , roll angle γ i and the heading angle ψ; Wherein, i refers to the i-th first MEMS attitude sensor, i=1,2,3,4,…; S3, detect the pitch angle θ of the vehicle body m , roll angle γ m And the heading angle ψ: The second MEMS attitude sensor detects the vehicle's driving condition and outputs the vehicle's pitch angle θ m , roll angle γ m and the heading angle ψ; S4. Calculate the roll compensation angle Δγ i : The roll angle γ of each spring steel plate output by multiple first MEMS attitude sensors i and the vehicle body roll angle γ m Calculate the roll compensation angle Δγ i , roll compensation is performed on multiple spring steel plates respectively, and the roll compensation angle Δγ i The calculation formula is: Dg i =c i -c m (1); S5. Calculate the pitch compensation angle Δθ i : The pitch angle θ of each spring steel plate output by each first MEMS attitude sensor i and the vehicle pitch angle θ m Calculate the pitch compensation angle Δθ i , perform pitch compensation on multiple spring steel plates respectively, and the pitch compensation angle Δθ i The calculation formula is: Dth i =θ i -θ m (2); S6. Calculate the load Δq of the spring steel plate i :The relationship between the deflection of the spring steel plate and its load is linearized to obtain the proportional coefficient k. The spring steel plate is simplified into a simply supported beam. The load Δq of the spring steel plate is calculated based on the pitch compensation angle using the following formula: i : Where, E is the elastic modulus, I is the section moment of inertia, and l is the length; S7. Calculate the actual load q of the spring steel plate i : According to the roll compensation angle Δγ i The spring steel plate is subjected to force correction and the actual load q of the spring steel plate is calculated using the following formula: i : S8. Calculate the total vehicle weight q: Calculate the actual load q of each spring steel plate in sequence according to step S6 and step S7. i , and calculate the total vehicle weight q according to formula (5): q=q1+q2+…+q i (5); Among them, q1, q2, …q i are the actual loads of the 1st, 2nd, ..., ith spring steel plates respectively.

2. The vehicle weight measurement method based on MEMS attitude sensor according to claim 1 is characterized in that: The difference between the heading angle output by the second mems attitude sensor and the heading angle output by a first mems attitude sensor is calculated. When the difference between the two is greater than a difference threshold, it is determined that the first mems attitude sensor or the second mems attitude sensor is faulty.

3. The vehicle weight measurement method of the MEMS attitude sensor according to claim 1 is characterized in that: The first mems attitude sensor and the second mems attitude sensor have the same structure.

4. The vehicle weight measurement method of the MEMS attitude sensor according to claim 3 is characterized in that: The first mems attitude sensor and the second mems attitude sensor include a three-axis gyroscope, a three-axis accelerometer, and a three-axis electronic compass motion sensor.

5. The vehicle weight measurement method of the MEMS attitude sensor according to claim 1 is characterized in that: In step S1, a plurality of first MEMS attitude sensors are respectively installed in different areas of the vehicle.

6. The vehicle weight measurement method of the MEMS attitude sensor according to claim 1 is characterized in that: In step S6, the relationship between the deflection of the spring steel plate and its load is linearized to obtain the proportional coefficient k in the following specific steps: Each time a load ΔP is applied to the leaf spring i = 200kg, perform n calibrations, take the spring steel plate deflection as the horizontal axis and mark it as w i , the load is longitudinal and marked as P i , we get the point set (w i , P i )(i=1, 2, 3, ···, 51), after curve fitting, the load and deflection curve of the spring steel plate is obtained.

7. A measurement system for the vehicle weight measurement method based on MEMS attitude sensor according to claim 1, characterized in that: It comprises a plurality of first mems attitude sensors and a second mems attitude sensor, wherein the plurality of first mems attitude sensors are fixedly connected to the supporting spring steel plates of each wheel or the load-bearing area of ​​the vehicle body, and the second mems attitude sensor is fixedly connected to the vehicle cross beam.

8. The measuring system according to claim 7, characterized in that: The structures of the plurality of first mems attitude sensors and the second mems attitude sensors are the same, and both include a three-axis gyroscope, a three-axis accelerometer, and a three-axis electronic compass motion sensor.

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