CN-122016121-A - Tractor traction force measuring device and measuring method

CN122016121ACN 122016121 ACN122016121 ACN 122016121ACN-122016121-A

Abstract

The invention relates to a traction force measuring device and a traction force measuring method of a tractor, wherein the measuring device comprises a tractor side force transmission frame, an agricultural tool side force transmission frame, an integrated traction force sensor, a measuring host and a GNSS antenna, the integrated traction force sensor comprises a sensor body, a shaft force measuring full bridge and a shearing force measuring full bridge, a signal conditioning module is further arranged on the sensor body and used for acquiring a pulling force along an axis of the sensor and a shearing force perpendicular to the axis of the sensor and converting the pulling force and the shearing force into traction force under a geodetic coordinate system, and the measuring host is used for acquiring attitude information of the tractor and converting the received traction force under the geodetic coordinate system from the signal conditioning module into real traction force under the coordinates of the tractor. The measuring method is based on the measuring device to measure the real traction force of the tractor. The invention has simple and quick installation, can obtain the real traction force of the tractor in real time, lighten the data processing workload of testers and improve the measurement accuracy.

Inventors

LEI LONG
Jiao Juzhe
MA MEILIAN
HU HAO
YANG QIANWEN
LIU XIAOFENG
ZHANG YIWEI
ZHAO JUNJIE
Guo Ruiyu
XUE RUNZE

Assignees

洛阳西苑车辆与动力检验所有限公司

Dates

Publication Date: 20260512
Application Date: 20260210

Claims (10)

1. A tractor traction measuring device, comprising: A tractor side force transmission frame (10) for connecting with a tractor; A farm tool side force transmission frame (11) for connecting farm tools; the two ends of the integrated traction force sensor (12) are fixedly connected with the tractor side force transmission frame (10) and the farm tool side force transmission frame (11) respectively; the measuring host machine (14) is arranged on the tractor (1), and the coordinate system of the measuring host machine (14) is overlapped with the coordinate system of the tractor; a GNSS antenna (13) which is arranged on the tractor (1) and is connected with the measurement host (14); The integrated traction force sensor (12) comprises a sensor body (20), an axial force measurement full bridge and a shear force measurement full bridge, wherein the axial force measurement full bridge is arranged along the axis of the sensor body (20) and is used for measuring the tensile force along the axis direction, the shear force measurement full bridge is arranged along the axis of the sensor body (20) and is used for measuring the shear force perpendicular to the axis, the sensor body (20) is further provided with a signal conditioning module (29), and the signal conditioning module (29) is used for acquiring and processing signals of the axial force measurement full bridge and the shear force measurement full bridge to acquire the tensile force along the axis of the sensor and the shear force perpendicular to the axis of the sensor, acquiring the attitude information of the integrated traction force sensor (12) and converting the tensile force and the shear force into the traction force under a geodetic coordinate system based on the attitude information; the measuring host (14) is used for acquiring the attitude information of the tractor (1) and converting the traction force received from the signal conditioning module (29) under the geodetic coordinate system into the actual traction force under the tractor coordinate.
2. The tractor traction force measuring device according to claim 1, wherein the tractor side force transmission frame (10) and the farm tool side force transmission frame (11) comprise a force transmission body (16) and a shearing groove (17) and a calibration ring fixing groove (18) which are arranged on the force transmission body (16), the calibration ring fixing groove (18) is used for accommodating a calibration ring of the integrated traction force sensor (20) and fixing the calibration ring through a fixing piece to realize positioning in the axial direction, the shearing groove (17) is used for being clamped with the end part of the integrated traction force sensor (12) to realize positioning in the circumferential direction, and the force transmission body (16) is further provided with a hanging arm for connecting the tractor (1) or the farm tool (2).
3. The traction force measuring device for a tractor according to claim 1, wherein the axle force measuring full bridge comprises a first axle force strain gauge (21), a second axle force strain gauge (22), a first axle force compensation strain gauge (23) and a second axle force compensation strain gauge (24) which are arranged on the left side surface and the right side surface of the sensor body (20), the first axle force strain gauge (21) and the second axle force strain gauge (22) are symmetrically arranged, and the first axle force compensation strain gauge (23) and the second axle force compensation strain gauge (24) are symmetrically arranged.
4. The tractor traction force measuring device according to claim 1, wherein the shear force measuring full bridge comprises a first 45-degree shear strain gauge (25), a second 45-degree shear strain gauge (26), a first-45-degree shear strain gauge (27) and a second-45-degree shear strain gauge (28) which are arranged on the left side surface and the right side surface of the sensor body (20), the first 45-degree shear strain gauge (25) and the second 45-degree shear strain gauge (26) are symmetrically arranged, and the first-45-degree shear strain gauge (27) and the second-45-degree shear strain gauge (28) are symmetrically arranged.
5. The tractor traction measurement device according to claim 1, wherein the signal conditioning module (29) comprises a conditioning IMU chip (39) for measuring three-axis acceleration and three-axis angular velocity of the sensor body (20) in space in real time; the conditioning central processing unit (37) analyzes the posture and the rotation matrix Cbn of the integrated traction force sensor (12) according to the triaxial acceleration and the triaxial angular velocity of the sensor body (20), and converts the tensile force and the shearing force into traction force under a geodetic coordinate system; and the transceiver chip (40) is used for transmitting the rotation matrix Cbn and the traction force under the geodetic coordinate system to the measurement host (14).
6. The tractor traction force measurement device of claim 1, wherein the measurement host (14) includes a host IMU chip (47) for acquiring a tri-axial acceleration and a tri-axial angular velocity of the measurement host (14); And the host central processing unit (46) is used for calculating the posture and rotation matrix Cnb of the tractor (1) according to the triaxial acceleration and the triaxial angular velocity of the measurement host (14) and converting the traction force under the geodetic coordinate system into the real traction force under the tractor coordinate.
7. The tractor traction force measurement device of claim 6, wherein the host central processing unit (46) is further configured to read vehicle state information of the tractor (1) through an OBD interface (44) and a CAN transceiver chip (45) of the measurement host (14), and obtain position and speed information of the tractor (1) through a GNSS module (49) of the measurement host (14), and store the vehicle state information, position and speed information in association with the real traction force in a memory of the measurement host (14).
8. A tractor traction measuring method, characterized in that the method adopts the tractor traction measuring device according to any one of claims 1-7, comprising the steps of: Aligning a measuring host (14) with a coordinate system of the integrated traction force sensor (12), and carrying out posture data fusion calibration after powering on to enable posture data of the measuring host and the integrated traction force sensor to be consistent; Secondly, connecting two ends of an integrated traction force sensor (12) with a tractor (1) and an agricultural implement (2) through a tractor side force transmission frame (10) and an agricultural implement side force transmission frame (11) respectively; The third step, the signal conditioning module (29) measures the full bridge to measure the X-direction tension force F x through the axial force, measures the full bridge to measure the Z-direction shearing force F z through the shearing force, measures the triaxial acceleration and triaxial angular velocity of the sensor body (20) in space through the conditioning IMU chip (39), calculates the posture and the rotation matrix Cbn of the integrated traction force sensor (12), and converts the tension force F x and the shearing force F z into the absolute horizontal tension force F xh and the vertical tension force F zh pointing to the earth center under the earth coordinate system; Fourth, the measurement host (14) collects the triaxial acceleration and triaxial angular velocity of the measurement host (14) through the host IMU chip (47), calculates the posture and rotation matrix Cnb of the tractor (1), and converts the received absolute horizontal pulling force F xh and the pulling force F zh which vertically points to the earth center into the real forward pulling force F xt and the downward pulling force F zt of the tractor.
9. The tractor traction force measurement method according to claim 1, wherein the axial force calibration coefficient of the integrated traction force sensor (12) is obtained before measurement, the method is that two ends of the integrated traction force sensor (12) are respectively connected with two ends of a tension tester, the tension tester applies gradually increased tension along the axial direction of the sensor body (20) until a preset target tension, meanwhile, a signal conditioning module (29) records an axial force measurement voltage difference signal corresponding to each tension, and the axial force calibration coefficient of the integrated traction force sensor (12) is calculated according to the plurality of tension values and the axial force measurement voltage difference signals corresponding to the tension values.
10. The tractor traction force measurement method according to claim 1, wherein the shear force calibration coefficient of the integrated traction force sensor (12) is obtained before measurement, the method is that two ends of the integrated traction force sensor (12) are respectively connected with the upper end face and the lower end face of a shear force tester, gradually increasing shear force is applied to the integrated traction force sensor along the direction perpendicular to the axis of the sensor body (20) through the shear force tester until a preset target shear force is achieved, meanwhile, a signal conditioning module (29) records shear force measurement voltage difference signals corresponding to each shear force, and the shear force calibration coefficient of the integrated traction force sensor (12) is calculated according to the plurality of shear force values and the shear force measurement voltage difference signals corresponding to the shear force values.

Description

Tractor traction force measuring device and measuring method Technical Field The invention belongs to the technical field of tractor testing, and particularly relates to a tractor traction force measuring device and a tractor traction force measuring method. Background When the tractor mounts farm tools to work, the traction force of the tractor is often required to be measured, and the structure of a common traction force measuring device is shown in fig. 1. In general, the tractor 1 needs to be connected with the agricultural implement 2 through an upper pull rod 3, a right lower pull rod 4 and a left lower pull rod 5 when working. Therefore, an upper pull rod pressure sensor 6, an upper pull rod angle sensor 7, a lower pull rod pin shaft sensor 9 and a lower pull rod angle sensor 8 are generally required to be installed, and then all measurement signals are transmitted to a data acquisition device to calculate and obtain the traction force of the tractor 1. However, this traction test has several problems: 1. the upper pull rod needs to be customized, and the pull rod needs to be connected with a pull pressure sensor in series. 2. The pin force sensor needs to be customized, and different vehicle types need to be customized with various pin force sensors. 3. The installation and the debugging are complex, 3 pulling forces and 3 angle sensors are required to be connected in total, and the next test is replaced after the test is finished, and the debugging and the calibration are required to be repeated. 4. The data processing is complex, the testers need to manually program and calculate the obtained 3 pulling forces and 3 angle sensors, and the matrix operation is involved, so that the data processing level of the testers is high. 5. The angle sensor can only convert three force sensors to obtain an absolute horizontal direction, but the tractor is not in a horizontal state in most cases when working, so the measured traction force error is large. Disclosure of Invention In order to solve the defects in the prior art, the invention provides the tractor traction force measuring device and the tractor traction force measuring method, which only need to hang the measuring device on a tractor, hang farm tools on the measuring device, then put a measuring host into a vehicle to start the test, have simple and quick installation, can obtain the real traction force of the tractor in real time, lighten the data processing workload of testers and improve the measurement precision. In order to achieve the above purpose, the invention adopts the technical scheme that the traction force measuring device of the tractor comprises: The tractor side force transmission frame is used for connecting a tractor; The farm tool side force transmission frame is used for connecting farm tools; the two ends of the integrated traction force sensor are fixedly connected with the tractor side force transmission frame and the farm tool side force transmission frame respectively; the measuring host is arranged on the tractor, and the coordinate system of the measuring host is overlapped with the coordinate system of the tractor; the GNSS antenna is arranged on the tractor and is connected with the measurement host; The integrated traction force sensor comprises a sensor body, a shaft force measurement full bridge and a shearing force measurement full bridge, wherein the shaft force measurement full bridge is arranged along the axis of the sensor body and is used for measuring the tensile force along the axis direction; the sensor body is also provided with a signal conditioning module, wherein the signal conditioning module is used for acquiring and processing signals of the axial force measurement full bridge and the shear force measurement full bridge to acquire a tensile force along the axis of the sensor and a shearing force perpendicular to the axis of the sensor, acquiring posture information of the integrated traction force sensor and converting the tensile force and the shearing force into traction force under a geodetic coordinate system based on the posture information; The measuring host is used for acquiring the attitude information of the tractor and converting the received traction force from the signal conditioning module under the geodetic coordinate system into the actual traction force under the tractor coordinate. The calibration ring fixing groove is used for accommodating a calibration ring of the integrated traction force sensor and fixing the calibration ring through a fixing piece so as to realize positioning in the axial direction, the shearing groove is used for being clamped with the end part of the integrated traction force sensor so as to realize positioning in the circumferential direction, and the force transmission body is also provided with a hanging arm connected with a tractor or an agricultural implement. Further, the axial force measurement full bridge comprises a first axial force strain gauge, a