Torque control method and system based on hydraulic loading device
阅读说明：本技术 一种基于液力加载装置的扭矩控制方法及系统 (Torque control method and system based on hydraulic loading device ) 是由 王贵勇 马强 常青 张爱国 王晓永 赵军 吕岩 郭永杰 刘庆华 汤若奇 毛晓宇 于 2019-10-10 设计创作，主要内容包括：本发明公开了一种基于液力加载装置的扭矩控制方法及系统,该方法是通过扭矩反馈,闭环控制流体对运动物体的阻力来形成液力加载装置所需的扭矩负载,可以解决液力加载装置在加载过程中对加载扭矩精确控制的问题。本发明的方法及系统以液力加载装置工作时产生的流体阻力作为控制量,比例溢流阀的工作参数作为调节量,通过PID调节器计算出控制量参数,实时调整液力加载装置液压腔内的油液压力,实现对流体阻力的控制,从而在液压加载装置的输出端得到准确的扭矩输出值。(The invention discloses a torque control method and a torque control system based on a hydraulic loading device. The method and the system of the invention take the fluid resistance generated when the hydraulic loading device works as the control quantity, the working parameter of the proportional relief valve as the regulating quantity, the control quantity parameter is calculated by the PID regulator, the oil pressure in the hydraulic cavity of the hydraulic loading device is regulated in real time, and the control on the fluid resistance is realized, thereby obtaining the accurate torque output value at the output end of the hydraulic loading device.)
1. A torque control method based on a hydraulic loading device is characterized by comprising the following steps:
when the hydraulic loading device works, a torque control value is compared with a torque sensor value on a transmission shaft to be used as input, a PID (proportion integration differentiation) regulator is used for obtaining a fluid resistance control quantity parameter of a hydraulic cavity in real time, controlling a working parameter of a proportional overflow valve at the outlet of the hydraulic cavity and adjusting the oil pressure in the hydraulic cavity of the hydraulic loading device in real time, the oil pressure is used for controlling the fluid resistance of the hydraulic cavity of the hydraulic loading device, and the torque control value is obtained at the output end of the hydraulic loading device;
the hydraulic loading device comprises a transmission shaft and a gear, wherein the transmission shaft drives the gear to rotate in the oil hydraulic cavity; the outlet of the hydraulic cavity of the oil liquid is provided with a proportional overflow valve, the proportional overflow valve can adjust the opening size of the oil outlet of the hydraulic cavity, the gear rotates in the hydraulic cavity to generate fluid resistance, and the transmission shaft is provided with a torque sensor.
2. A torque control system based on a hydraulic loading device is characterized by comprising the hydraulic loading device and a PID regulator,
the hydraulic loading device comprises a transmission shaft and a gear, and the transmission shaft drives the gear to rotate in oil; the outlet of the pressure cavity of the oil liquid is provided with a proportional overflow valve, the proportional overflow valve can adjust the opening size of the oil outlet of the pressure cavity of the oil liquid, a transmission shaft of the hydraulic loading device rotates, a gear rotates in the oil liquid to generate fluid resistance, and the transmission shaft is provided with a torque sensor;
the torque control value is compared with a torque sensor value on a transmission shaft and is input as a PID regulator, the working parameters of a proportional overflow valve at the outlet of a hydraulic cavity are obtained in real time through the PID regulator, the oil hydraulic pressure in the hydraulic cavity of the hydraulic loading device is adjusted in real time and is used for controlling the hydraulic resistance of the hydraulic cavity of the hydraulic loading device, and the torque control value is obtained at the output end of the hydraulic loading device.
3. A torque control method based on a hydraulic loading device is characterized by comprising the following steps:
s1: determining the torque required to be obtained as a torque M1;
s2: according to the torque feedback signal generated by the torque sensor, the torque is M2, and the torque is compared with the torque M1 to obtain a torque difference value delta M; a PID regulator is adopted, so that the difference value delta M between the torque M2 and the torque M1 is zero, and working parameters of the proportional overflow valve, which represent the size of the opening of the overflow valve, are obtained;
the specific control process of the PID regulator is as follows: inputting a torque difference value delta M, outputting a working parameter of the proportional overflow valve, which represents the opening size of the overflow valve, through a PID (proportion integration differentiation) regulator, and executing the opening size of the proportional overflow valve according to the working parameter, so that the pressure of the oil in a hydraulic cavity in the hydraulic loading device is changed; then the torque M2 of the torque sensor changes correspondingly; the PID regulator outputs new working parameters representing the size of the overflow valve opening again;
when the torque value M2 of the torque sensor changes to the value when the difference value with the torque M1 of the torque demand signal reaches a certain required range or is zero, the PID regulator controls the working parameters of the proportional relief valve to reach a stable value;
s3: the proportional overflow valve adopts a stable value of the proportional overflow valve output by a PID regulator;
s4: the torque M2 output by the torque sensor at this time is the required torque.
Wherein, the hydraulic loading device is specifically limited to: the hydraulic oil pump comprises a transmission shaft and a gear, wherein the transmission shaft drives the gear to rotate in an oil hydraulic cavity; the outlet of the hydraulic cavity of the oil liquid is provided with a proportional overflow valve, the proportional overflow valve can adjust the opening size of the oil outlet of the hydraulic cavity, the gear rotates in the hydraulic cavity to generate fluid resistance, and the transmission shaft is provided with a torque sensor.
4. A torque control method based on a hydraulic loading device as claimed in claim 3, characterized in that the hydraulic loading device is specifically defined by replacing: the device comprises a cooling shell (1), a box body (2), a gear (3), a bearing, a transmission shaft (9), a proportional overflow valve (12), an elastic coupling (14), a torque sensor (15) and a gear positioning sleeve (17); the box body (2) is internally provided with a central hole to form a hydraulic cavity; the transmission shaft (9) penetrates through a central hole of the box body, and the gear (3) is positioned in a hydraulic cavity, namely the central hole of the box body and assembled on the transmission shaft (9); the transmission shafts (9) positioned at the two ends of the gear (3) are respectively provided with a gear positioning sleeve (17); two ends of the gear positioning sleeve (17) are provided with bearings; the bearing is assembled on the transmission shaft (9), and the front part and the rear part of the hydraulic cavity are respectively provided with an end cover; the end cover positioned in front comprises a front bearing supporting end cover and a front shaft seal end cover, and a hydraulic cavity of the box body (2) is communicated with an oil outlet pipeline and an oil inlet; a proportional overflow valve (12) is arranged on the oil outlet pipeline; the torque sensor (15) is connected with one end of the transmission shaft (9) through an elastic coupling (14).
5. A hydraulic loading unit based torque control method as defined in claim 4 wherein the hydraulic loading unit further defines: the end cap at the rear is a rear bearing support end cap.
6. A hydraulic loading unit based torque control method as defined in claim 4 wherein the hydraulic loading unit further defines: the transmission shaft is provided with a circumferential boss which is positioned between the front shaft seal end cover and the bearing and used for limiting.
7. A hydraulic loading unit based torque control method as defined in claim 4 wherein the hydraulic loading unit further defines: the gear transmission shaft support device is characterized by further comprising a locking screw and a support cap, wherein the support cap is fixed at the right end of the transmission shaft through the locking screw and is pressed against the bearing, the gear positioning sleeve and the gear.
8. A hydraulic loading unit based torque control method as defined in claim 4 wherein the hydraulic loading unit further defines: an oil sealing groove is arranged between the front shaft seal end cover and the transmission shaft.
9. A hydraulic loading unit based torque control method as defined in claim 4 wherein the hydraulic loading unit further defines: and a sealing ring is arranged between the front bearing supporting end cover and the transmission shaft.
10. A hydraulic loading unit based torque control method as defined in claim 4 wherein the hydraulic loading unit further defines: the torque sensor is connected with the device to be tested through a second elastic coupling.
Technical Field
The invention belongs to the technical field of engineering hydromechanics application, and provides a torque control method based on a hydraulic loading device.
Background
When a moving object moves relatively in a fluid, the object is subjected to resistance of the fluid, and the resistance is related to various factors such as the density of the fluid, the viscosity of the fluid, the gradient of the velocity change of the fluid, the contact area, the surface roughness of the contact surface and the like. The generation reasons of the fluid resistance are various, various control methods and parameters of the fluid resistance cannot be obtained through a conventional and effective means, a proper and accurate calculation formula is not available, the traditional control method is mostly finished by the past experience or field debugging, and the accurate control of the torque cannot be realized.
The traditional method cannot accurately control the fluid resistance;
when the speed of the object movement and the temperature of the fluid change, the fluid resistance also changes correspondingly, and the traditional control method cannot realize automatic compensation because a closed loop is not formed.
Disclosure of Invention
The invention aims to provide a torque control method based on a hydraulic loading device, which forms a torque load required by the hydraulic loading device by carrying out torque feedback and closed-loop control on the resistance (fluid resistance for short) of fluid to a moving object, and can solve the problem of accurate control on the loading torque of the hydraulic loading device in the loading process.
The hydraulic loading device can form a torque closed loop by adopting the method in the loading test process, dynamically controls the height and the pressure of fluid in the hydraulic cavity so as to change the fluid resistance, quickly forms an accurate and stable torque load, and meets the requirement of the hydraulic loading device on accurate change of the torque in the loading test.
Compared with the traditional method, the invention has the following advantages: specific formula calculation is avoided, and the logic is simple and easy to realize; the closed-loop control of the torque ensures that the simulated torque load is accurate and stable, and ensures that the data acquired by the hydraulic loading device in the loading test is accurate.
The technical scheme provided by the invention is as follows: a torque control method based on a hydraulic loading device is characterized by comprising the following steps: when the hydraulic loading device works, a torque control value is compared with a torque sensor value on a transmission shaft to be used as input, a PID (proportion integration differentiation) regulator is used for obtaining a fluid resistance control quantity parameter of a hydraulic cavity in real time, controlling a working parameter of a proportional overflow valve at the outlet of the hydraulic cavity and adjusting the oil pressure in the hydraulic cavity of the hydraulic loading device in real time, the oil pressure is used for controlling the fluid resistance of the hydraulic cavity of the hydraulic loading device, and the torque control value is obtained at the output end of the hydraulic loading device; the hydraulic loading device comprises a transmission shaft and a gear, wherein the transmission shaft drives the gear to rotate in the oil hydraulic cavity; the outlet of the hydraulic cavity of the oil liquid is provided with a proportional overflow valve, the proportional overflow valve can adjust the opening size of the oil outlet of the hydraulic cavity, the gear rotates in the hydraulic cavity to generate fluid resistance, and the transmission shaft is provided with a torque sensor.
A torque control system based on a hydraulic loading device is characterized by comprising the hydraulic loading device and a PID regulator, wherein the hydraulic loading device comprises a transmission shaft and a gear, and the transmission shaft drives the gear to rotate in oil; the outlet of the pressure cavity of the oil liquid is provided with a proportional overflow valve, the proportional overflow valve can adjust the opening size of the oil outlet of the pressure cavity of the oil liquid, a transmission shaft of the hydraulic loading device rotates, a gear rotates in the oil liquid to generate fluid resistance, and the transmission shaft is provided with a torque sensor; the torque control value is compared with a torque sensor value on a transmission shaft and is input as a PID regulator, the working parameters of a proportional overflow valve at the outlet of a hydraulic cavity are obtained in real time through the PID regulator, the oil hydraulic pressure in the hydraulic cavity of the hydraulic loading device is adjusted in real time and is used for controlling the hydraulic resistance of the hydraulic cavity of the hydraulic loading device, and the torque control value is obtained at the output end of the hydraulic loading device.
A torque control method based on a hydraulic loading device is characterized by comprising the following steps:
s1: determining the torque required to be obtained as a torque M1;
s2: according to the torque feedback signal generated by the torque sensor, the torque is M2, and the torque is compared with the torque M1 to obtain a torque difference value delta M; a PID regulator is adopted, so that the difference value delta M between the torque M2 and the torque M1 is zero, and working parameters of the proportional overflow valve, which represent the size of the opening of the overflow valve, are obtained;
the specific control process of the PID regulator is as follows: inputting a torque difference value delta M, outputting a working parameter of the proportional overflow valve, which represents the opening size of the overflow valve, through a PID (proportion integration differentiation) regulator, and executing the opening size of the proportional overflow valve according to the working parameter, so that the pressure of the oil in a hydraulic cavity in the hydraulic loading device is changed; then the torque M2 of the torque sensor changes correspondingly; the PID regulator outputs new working parameters representing the size of the overflow valve opening again;
when the torque value M2 of the torque sensor changes to the value when the difference value with the torque M1 of the torque demand signal reaches a certain required range or is zero, the PID regulator controls the working parameters of the proportional relief valve to reach a stable value;
s3: the proportional overflow valve adopts a stable value of the proportional overflow valve output by a PID regulator;
s4: the torque M2 output by the torque sensor at this time is the required torque.
Wherein, the hydraulic loading device is specifically limited to: the hydraulic oil pump comprises a transmission shaft and a gear, wherein the transmission shaft drives the gear to rotate in an oil hydraulic cavity; the outlet of the hydraulic cavity of the oil liquid is provided with a proportional overflow valve, the proportional overflow valve can adjust the opening size of the oil outlet of the hydraulic cavity, the gear rotates in the hydraulic cavity to generate fluid resistance, and the transmission shaft is provided with a torque sensor.
The invention has the technical effects that:
the torque control method based on the hydraulic loading device provided by the invention adopts the closed-loop control of the fluid resistance, can accurately simulate the actual load torque required by the hydraulic loading device, is sensitive in control, quick and accurate in response, can be widely applied to the loading tests of various vehicle transmission cases and gear box bodies, provides accurate test data for various parameter indexes of transmission case components, and well realizes the quality control of the vehicle before the integral assembly. In addition, the method can also provide accurate torque for various hydraulic torque converters and hydraulic speed reducers under different rotating speeds, oil media and temperatures.
Drawings
FIG. 1 is a schematic diagram of the resistance of a fluid to a moving object;
FIG. 2 is a torque control logic block diagram of the torque control method of the present invention.
Fig. 3 is a schematic structural diagram of a hydraulic loading device.
Detailed Description
The present invention is described in further detail below.
The principle of the invention is as follows:
hydrodynamics states that when an object moves in a fluid, a fluid resistance t is generated due to the viscosity and compressibility of the fluid. The method adopts a self-correcting and self-adaptive algorithm to control the fluid resistance t of the hydraulic loading device during working in a closed loop manner, so as to obtain the required loading torque.
The hydraulic resistance t generated by the hydraulic loading device during operation can be approximately considered as two parts: differential pressure resistance t1 and internal friction t2, i.e., t ≈
As shown in fig. 1: when a gear shaft of the hydraulic loading device rotates anticlockwise, a large amount of eddy can be formed on two side surfaces of the gear due to separation of streamline generated by liquid viscosity, pressure intensity of an eddy area is reduced, and accordingly great pressure difference resistance t1 is formed on two sides of the gear, and if the resistance coefficient of fluid is CDThe density is rho, the contact area of the fluid perpendicular to the moving direction and the tooth surface of the gear shaft is A, the linear velocity is V, the number of teeth of the gear shaft in contact with the fluid is n, and then the gear is in the fluidDifferential pressure resistance t1 ≈ n × C during internal movementD*ρ*A*V2/2. And the internal friction force t2 generated by the relative motion between the fluids is converted according to Newton's law of internal friction to obtain the internal friction force t2 ═ n × μ A, wherein μ is a viscosity coefficient, n is the number of teeth in contact with the fluids, and A represents a contact area and represents a velocity gradient of the fluids.
As can be seen from the above equation: the pressure difference resistance t1 and the internal friction force t2 generated when the hydraulic loading device works are related to the fluidity of the fluid; and the pressure of the oil is changed, the fluidity of the oil is changed, and the fluid resistance t is correspondingly changed. It can thus be derived: the fluid resistance t which can be adjusted at any time within a certain range and is relatively stable can be obtained at different rotating speeds by changing the pressure P of the fluid in the hydraulic cavity of the hydraulic loading device in real time.
The key of the method is as follows: the hydraulic loading device is characterized in that the hydraulic resistance generated when the hydraulic loading device works is used as a control quantity, the working parameter of the proportional overflow valve is used as an adjustment quantity, the control quantity parameter (the working parameter for controlling the proportional overflow valve) is calculated through the PID adjuster, the oil hydraulic pressure in the hydraulic cavity of the hydraulic loading device is adjusted in real time, and the control on the hydraulic resistance t is realized, so that an accurate torque output value is obtained at the output end of the hydraulic loading device.
The specific working process is as shown in the logic block diagram of fig. 2: the torque input signal M1 is compared with the feedback signal M2 of the torque sensor to generate a torque deviation delta M, the PID regulator calculates working parameters (representing the opening size of the overflow valve) of the proportional overflow valve, so that a certain oil pressure is generated in a hydraulic cavity of the hydraulic loading device, the change of the oil pressure causes the change of the internal friction force t, the changed internal friction force t generates a new torque feedback signal M2 through the torque sensor, and then is compared with M1 to form a new delta M, the working parameters of the proportional overflow valve are rapidly adjusted in real time through the torque feedback quantity PID regulator, so that the pressure of the oil in the hydraulic cavity is rapidly changed, and when the torque demand signal M1 is approximately equal to the feedback signal M2 of the torque sensor (namely, the delta M is approximately equal to 0), the PID regulator reaches a relatively steady state, and generates required fluid resistance.
When the working parameters or the rotating speed of the hydraulic loading device change, the PID regulator starts to work again to form a torque closed loop, so that an accurate torque output value is obtained at the output end of the hydraulic loading device.
A torque control method based on a hydraulic loading device comprises the following steps:
the method comprises the following steps:
s1: determining the required torque as the torque M1 (or the torque input M1);
s2: according to the torque feedback signal generated by the torque sensor, namely the torque M2 (or referred to as torque feedback M2), comparing the torque M with the torque M1 to obtain a torque difference value delta M; a PID regulator is adopted, so that the difference value delta M between the torque M2 and the torque M1 is zero, and working parameters of the proportional overflow valve, which represent the size of the opening of the overflow valve, are obtained;
the specific control process of the PID regulator is as follows: inputting a torque difference value delta M, outputting a working parameter of a proportional overflow valve representing the opening size of the overflow valve through a PID (proportion integration differentiation) regulator, and executing the opening size of the proportional overflow valve according to the working parameter, so that the pressure of oil in a hydraulic cavity (pressure cavity) in the hydraulic loading device is changed; then the torque M2 of the torque sensor changes correspondingly; the PID regulator outputs new working parameters representing the size of the overflow valve opening again;
when the torque value M2 of the torque sensor changes to a range (or zero) where the difference value between the torque value M2 of the torque sensor and the torque M1 of the torque demand signal reaches a certain requirement, the PID regulator controls the working parameters of the proportional relief valve to reach a stable value;
s3: the proportional overflow valve adopts a stable value of the proportional overflow valve (representing the working parameter of the opening size of the overflow valve) output by a PID regulator.
S4: the torque M2 output by the torque sensor at this time is the required torque.
A torque control method based on a hydraulic loading device can be implemented on a Programmable Logic Controller (PLC), and can also be implemented by using a single chip microcomputer as a Proportion Integration Differentiation (PID) regulator through analog-digital and digital-analog conversion.