The efficiency of a field fleet unit is largely determined by the characteristics of the traction resistance of an agricultural machine, which are of a probabilistic nature and require experimental determination. The disadvantage of the known devices that provide measurements during the volumetric dynamometry of the working bodies of tillage machines and implements is the complexity of the design and a significant measurement error. To increase the accuracy of measurements of the dynamic loading of the working bodies of tillage machines, it is necessary to improve the measuring instruments that ensure the reduction of the error. The experimental determination of the loading of the working bodies requires the use of force sensors acting on the working bodies in different planes. Force transducers are mainly manufactured using strain gages, which are glued directly to parts with various cross-sections. To determine the efforts in the rods of the hydraulic linkage system of agricultural tractors use strain gauge fingers, which are cylinders with strain gages glued to them. It is shown that at equal distances l1 and l2 of the location of the sensors, the resulting signal does not depend on the l0 distance of force application on the axis of the finger. Typically, the calibration of force sensors is carried out on additional devices one by one under conditions as close as possible to real ones. The best calibration results will be when all sensors (strain gauge fingers) are installed in their original places and all sensors are calibrated at once. To do this, the intermediate plate is fixed with the help of tension fingers on the hydraulic tractor levers. Eyebolts are installed on the plate, to which a known force Р is applied three times and readings are taken from each of the strain gauge fingers. By solving the resulting system of equations, for example, using the Gauss method in the MathCad environment, all the calibration coefficients are simultaneously found. Additionally, a device is proposed, the kinematic diagram of which allows the use of a single measuring device, which simplifies the technology of measuring the force on the working body and increases its accuracy.
Multi-axis force sensing with pre-stressed resonant composite plates: An alternative to strain gauge force sensors
