An AMESim-based simulation method for a six-degree-of-freedom robot hydraulic system

Abstract

The application discloses a kind of six-degree-of-freedom robot hydraulic system simulation method based on AMESim, belongs to six-degree-of-freedom robot hydraulic system simulation technical field.The method includes S1: building hydraulic drive unit simulation model in AMESim;S2: building hydraulic oil source;S3: using the mode of Submodel in AMESim, using Premier submodel function gives submodel;S4: according to actual parameter, the parameter value of each element in the hydraulic drive unit simulation model and hydraulic oil source in S3 is set respectively;S5: based on the model obtained in S4, using Simulation mode enters simulation mode, completes the simulation of six-degree-of-freedom robot hydraulic system based on AMESim, obtains target joint rotation angle signal and the change curve of actual joint rotation angle.The application has the simulation to each hydraulic drive joint unit of six-degree-of-freedom robot, so as to master the motion of each drive joint unit, lays the foundation for the motion and accurate control of six-degree-of-freedom robot hydraulic system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of six-degree-of-freedom robot hydraulic system simulation, and particularly relates to a six-degree-of-freedom robot hydraulic system simulation method based on AMESim. BACKGROUND

[0002] The six-degree-of-freedom hydraulic robot (referred to as the six-degree-of-freedom robot in the application) has been widely applied in many fields such as industrial manufacturing, mine construction, medical assistance, logistics and warehousing, etc. due to its high load capacity, flexibility, precision and adaptability. Especially when large-scale resources are exploited, cutting is performed, and heavy objects are transported, the mechanical arm driven by the hydraulic drive can efficiently complete the task.

[0003] However, at present, the six-degree-of-freedom hydraulic robot is mostly driven by the joint rotation of the hydraulic motor, and the robot driven by the combination of the hydraulic cylinder and the hydraulic motor is less, and AMESim is used as the simulation platform, so that the hydraulic system can be more quickly constructed, and the simulation results can be more intuitively analyzed. SUMMARY

[0004] The application aims to overcome the defects in the prior art and provide a six-degree-of-freedom robot hydraulic system simulation method based on AMESim. The method can perform hydraulic simulation on each driving joint unit of the six-degree-of-freedom robot, so as to master the motion of each driving joint unit, and lay a foundation for the motion and accurate control of the six-degree-of-freedom robot hydraulic system.

[0005] The specific technical scheme adopted by the application is as follows:

[0006] The application provides a six-degree-of-freedom robot hydraulic system simulation method based on AMESim, which is as follows:

[0007] S1: according to the three-dimensional model of the six-degree-of-freedom robot established in Solidworks, a hydraulic driving unit simulation model of the six-degree-of-freedom robot hydraulic system is constructed in AMESim; the hydraulic driving unit simulation model includes a pitch joint part and a rotary joint part; the pitch joint part includes a shoulder pitch joint unit, an elbow pitch joint unit, a wrist vertical pitch joint unit and a wrist horizontal pitch joint unit, and the rotary joint part includes a waist rotary joint unit and an end rotary joint unit;

[0008] S2: based on the hydraulic driving unit simulation model in S1, a hydraulic oil source of the six-degree-of-freedom robot hydraulic system is constructed in AMESim;

[0009] S3: using the submodel mode in AMESim, using the Premier submodel function to give the submodel of the six-degree-of-freedom robot hydraulic system established in S1 and S2;

[0010] S4: according to the actual parameters of the six-degree-of-freedom robot hydraulic system to be simulated, setting the parameter values of each element in the simulation model of the hydraulic drive unit of the six-degree-of-freedom robot hydraulic system and the hydraulic oil source in S3;

[0011] S5: based on the results of S4, entering the simulation mode using the Simulation mode, completing the simulation of the six-degree-of-freedom robot hydraulic system based on AMESim, and obtaining the target joint rotation angle signal and the actual joint rotation angle change curve.

[0012] As preferred, the hydraulic oil source includes a cylinder, a filter, a motor, a hydraulic pump, a check valve and a relief valve; the parameters set in S4 include cylinder oil pressure, hydraulic pump displacement, motor rated speed, relief valve setting pressure, and the filter and check valve use the default values of AMESim.

[0013] As preferred, the setting modes of the waist rotation joint unit and the end rotation joint unit are the same, and each includes a three-position four-way electromagnetic reversing valve, a balance valve, a cycloidal motor, a torque unit, an angle sensor and a PID controller; the parameters set in S4 include the displacement of the cycloidal motor, the torque value of the torque unit, the parameters of the PID controller, and the three-position four-way electromagnetic reversing valve, the balance valve and the angle sensor all use the default values of AMESim.

[0014] Further, the PID controller controls the joint angle based on the following mathematical model:

[0015]

[0016] In the formula, u(t) is the output value of the controller; e(t) is the current error value; K p is the proportional parameter, K i is the integral parameter, K d is the differential parameter; ∫e(t) is the integral value of the error; is the differential value of the error.

[0017] As preferred, the setting modes of the shoulder pitch joint unit, the elbow pitch joint unit, the wrist vertical pitch joint unit and the wrist horizontal pitch joint unit are the same, and each includes a hydraulic cylinder displacement and joint angle function, a displacement sensor, a load unit and a hydraulic cylinder; the parameters set in S4 include the maximum working pressure, stroke, cylinder diameter and piston rod diameter, working temperature range of the hydraulic cylinder, and the hydraulic cylinder displacement and joint angle function, load unit size, and the displacement sensor uses the default values of AMESim.

[0018] Further, the hydraulic cylinder displacement and joint angle function is calculated by using the joint structure of Solidworks.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] (1) The method realizes the construction of the six-degree-of-freedom robot hydraulic system, and lays a foundation for the subsequent control of the six-degree-of-freedom robot.

[0021] (2) The PID control element used in the method can more accurately control the joint angle of the six-degree-of-freedom robot.

[0022] (3) In the method, the relationship between the hydraulic cylinder displacement and the joint angle is represented by function transformation, so as to realize the real-time feedback of the angle of each joint, and increase the authenticity and reliability of the model. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The basic structure of the six-degree-of-freedom robot is shown.

[0024] Figure 2 The AMESim model of the six-degree-of-freedom robot hydraulic system is shown.

[0025] Figure 3 The hydraulic oil source in the AMESim model of the six-degree-of-freedom robot hydraulic system is shown.

[0026] Figure 4 The waist rotation joint unit in the AMESim model of the six-degree-of-freedom robot hydraulic system is shown.

[0027] Figure 5 The shoulder pitch joint unit in the AMESim model of the six-degree-of-freedom robot hydraulic system is shown.

[0028] Figure 6 The angle change curve of the waist rotation joint unit in the embodiment is shown.

[0029] Figure 7 The angle change curve of the shoulder pitch joint unit in the embodiment is shown.

[0030] Marked in the figure: oil cylinder 1, filter 2, motor 3, hydraulic pump 4, check valve 5, overflow valve 6, three-position four-way electromagnetic reversing valve 7, balance valve 8, cycloidal motor 9, torque unit 10, angle sensor 11, PID controller 12, hydraulic cylinder displacement and joint angle function 13, displacement sensor 14, load unit 15, hydraulic cylinder 16. DETAILED DESCRIPTION

[0031] The application will be further described and illustrated with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the application can be combined accordingly without conflict.

[0032] The application provides a six-degree-of-freedom robot hydraulic system simulation method based on AMESim, which specifically comprises the following steps:

[0033] S1: Constructing a hydraulic schematic diagram of the six-degree-of-freedom robot hydraulic system according to the actual working conditions of the six-degree-of-freedom robot, which mainly comprises a hydraulic drive unit and a hydraulic oil source.

[0034] According to the three-dimensional model of the six-degree-of-freedom robot established in Solidworks, a hydraulic drive unit simulation model of the six-degree-of-freedom robot hydraulic system is constructed in AMESim. The hydraulic drive unit simulation model mainly comprises two parts, i.e., a pitch joint part and a rotary joint part. The pitch joint part comprises a shoulder pitch joint unit, an elbow pitch joint unit, a wrist vertical pitch joint unit and a wrist horizontal pitch joint unit, and the rotary joint part comprises a waist rotary joint unit and an end rotary joint unit.

[0035] S2: Based on the hydraulic drive unit simulation model of S1, a hydraulic oil source of the six-degree-of-freedom robot hydraulic system is constructed in AMESim. The hydraulic oil source is mainly used to provide constant pressure oil to ensure sufficient flow supply.

[0036] In this embodiment, the basic structure of the six-degree-of-freedom hydraulic robot is as shown in Figure 1 , and the AMESim model of the six-degree-of-freedom robot hydraulic system constructed is as shown in Figure 2 .

[0037] Specifically, as shown in Figure 3 , the hydraulic oil source mainly comprises two oil cylinders 1, two filters 2, one motor 3, one hydraulic pump 4, two one-way valves 5 and one overflow valve 6. The motor 3 is in driving connection with the hydraulic pump 4, the oil inlet end of the hydraulic pump 4 is connected with the first filter 2, the other end of the filter 2 is connected with the first oil cylinder 1, the oil outlet end of the hydraulic pump 4 is connected with the oil inlet end of the first one-way valve 5, the oil outlet end of the first one-way valve 5 is connected with the overflow valve 6; the second filter 2 and the second one-way valve 5 are connected in parallel, and the two ends of the second filter 2 and the second one-way valve 5 are respectively connected with the outlet of the overflow valve 6 and the second oil cylinder 1. The waist rotary joint unit and the end rotary joint unit are arranged in the same way, and mainly comprise a three-position four-way electromagnetic reversing valve 7, a balance valve 8, a cycloidal motor 9, a torque unit 10, an angle sensor 11 and a PID controller 12. The waist rotary joint unit in this embodiment is as shown in Figure 4As shown, the angle sensor 11 is connected to the cycloidal motor 9 for detecting the actual rotation angle of the cycloidal motor 9; the torque unit 10 is connected to the angle sensor 11 for applying torque to the cycloidal motor 9; the signal value of the angle sensor 11 is compared with the expected signal value to obtain an error signal, which is connected to the input end of the PID controller 12, and the output end of the PID controller 12 is connected to the three-position four-way electromagnetic reversing valve 7. The shoulder pitch joint unit, the elbow pitch joint unit, the wrist vertical pitch joint unit and the wrist horizontal pitch joint unit are set in the same way, and all mainly include a hydraulic cylinder displacement and joint angle function 13, a displacement sensor 14, a load unit 15 and a hydraulic cylinder 16. The shoulder pitch joint unit in the embodiment is shown as follows. Figure 5 As shown, the displacement sensor 14 is connected to the hydraulic cylinder 16 for detecting the piston displacement of the hydraulic cylinder 16; the load unit 15 is connected to the displacement sensor 14 for applying a load force to the hydraulic cylinder 16; the signal value of the displacement sensor 14 is converted into a joint rotation angle through the hydraulic cylinder displacement and joint angle function 13, which is compared with the expected rotation angle to obtain an error signal, which is connected to the input end of the PID controller 12, and the output end of the PID controller 12 is connected to the three-position four-way electromagnetic reversing valve 7.

[0038] Among them, the PID controller 12 controls the joint angle based on the following mathematical model:

[0039]

[0040] In the formula, u(t) is the output value of the controller; e(t) is the current error value; K p is the proportional parameter, K i is the integral parameter, K d is the differential parameter; ∫e(t) is the integral value of the error; is the differential value of the error.

[0041] S3: Use the Submodel mode in AMESim to use the Premier submodel function to give the submodel of the six-degree-of-freedom robot hydraulic system established in S1 and S2.

[0042] S4: According to the actual parameters of the six-degree-of-freedom robot hydraulic system to be simulated, set the parameter values of each element in the hydraulic drive unit simulation model of the six-degree-of-freedom robot hydraulic system and the hydraulic oil source in S3.

[0043] As a preferred embodiment of the present application, the parameters set in S4 by the hydraulic oil source include the oil pressure of the oil cylinder 1, the displacement of the hydraulic pump 4, the rated speed of the motor 3, the set pressure of the overflow valve 6, and the default values of the filter 2 and the check valve 5. The parameters set in S4 by the rotary joint part include the displacement of the cycloid motor 9, the torque value of the torque unit 10, the parameters of the PID controller 12, the default values of the three-position four-way electromagnetic reversing valve 7, the balance valve 8, and the angle sensor 11. The parameters set in S4 by the pitch joint part include the maximum working pressure, stroke, cylinder diameter, and piston rod diameter of the hydraulic cylinder 16, the working temperature range, the size of the hydraulic cylinder displacement and joint angle function 13, and the size of the load unit 15, and the default value of the displacement sensor 14. Among them, the hydraulic cylinder displacement and joint angle function 13 is calculated by the joint structure of Solidworks.

[0044] S5: Based on the results obtained in S4, enter the simulation mode using the Simulation mode to complete the simulation of the six-degree-of-freedom robot hydraulic system based on AMESim, and obtain the target joint rotation angle signal and the actual joint rotation angle change curve.

[0045] In this embodiment, the angle change curve of the waist rotation joint unit is as shown in Figure 6 The angle change curve of the shoulder pitch joint unit is as shown in Figure 7 As can be seen from the figure, the actual signal and the target signal trajectory are consistent, the followability is good, and the error is small, which shows that the joint rotation angle can be accurately controlled.

[0046] The present application has the advantages of simulating each hydraulic drive joint unit of the six-degree-of-freedom robot, so as to master the motion of each drive joint unit, and lays a foundation for the motion and accurate control of the six-degree-of-freedom robot hydraulic system.

[0047] The above-described embodiments are only a preferred scheme of the present application, and are not intended to limit the present application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. A simulation method for a six-degree-of-freedom robot hydraulic system based on AMESim, characterized in that, Specifically as follows: S1: Based on the 3D model of the six-degree-of-freedom robot built in Solidworks, construct a simulation model of the hydraulic drive unit of the six-degree-of-freedom robot hydraulic system in AMESim; the simulation model of the hydraulic drive unit includes a pitch joint and a rotation joint; the pitch joint includes a shoulder pitch joint unit, an elbow pitch joint unit, a wrist vertical pitch joint unit, and a wrist horizontal pitch joint unit; the rotation joint includes a waist rotation joint unit and an end effector rotation joint unit. S2: Based on the hydraulic drive unit simulation model described in S1, construct the hydraulic oil source for the six-degree-of-freedom robot hydraulic system in AMESim; S3: Using the Submodel mode in AMESim, the Premier submodel function is used to assign a submodel to the six-degree-of-freedom robot hydraulic system established in S1 and S2. S4: Based on the actual parameters of the hydraulic system of the six-degree-of-freedom robot to be simulated, set the simulation model of the hydraulic drive unit of the six-degree-of-freedom robot hydraulic system in S3 and the parameter values ​​of each component in the hydraulic oil source respectively. S5: Based on the results of S4, use the Simulation mode to enter the simulation mode, complete the simulation of the hydraulic system of the six-degree-of-freedom robot based on AMESim, and obtain the target joint rotation angle signal and the change curve of the actual joint rotation angle. The shoulder pitch joint unit, elbow pitch joint unit, wrist vertical pitch joint unit and wrist horizontal pitch joint unit are set in the same way, all including hydraulic cylinder displacement and joint angle function (13), displacement sensor (14), load unit (15) and hydraulic cylinder (16); the parameters set in S4 include the maximum working pressure, stroke, cylinder diameter and piston rod diameter, working temperature range of hydraulic cylinder (16) and hydraulic cylinder displacement and joint angle function (13), load unit (15) size, and the displacement sensor (14) adopts AMESim default value.

2. The simulation method for a six-degree-of-freedom robot hydraulic system based on AMESim according to claim 1, characterized in that, The hydraulic oil source includes a cylinder (1), a filter (2), a motor (3), a hydraulic pump (4), a check valve (5), and a relief valve (6); the parameters set in S4 include the oil pressure of the cylinder (1), the displacement of the hydraulic pump (4), the rated speed of the motor (3), the set pressure of the relief valve (6), and the default values ​​of the filter (2) and the check valve (5) are adopted by AMESim.

3. The simulation method for a six-degree-of-freedom robot hydraulic system based on AMESim according to claim 1, characterized in that, The waist rotation joint unit and the end rotation joint unit are configured in the same way, both including a three-position four-way solenoid valve (7), a balance valve (8), a cycloidal motor (9), a torque unit (10), an angle sensor (11), and a PID controller (12); the parameters set in S4 include the displacement of the cycloidal motor (9), the torque value of the torque unit (10), and the parameters of the PID controller (12). The three-position four-way solenoid valve (7), the balance valve (8), and the angle sensor (11) all use AMESim's default values.

4. The simulation method for a six-degree-of-freedom robot hydraulic system based on AMESim according to claim 3, characterized in that, The PID controller (12) controls the joint angle based on the following mathematical model: ； In the formula, The controller output value; This is the current error value; For proportional parameters, For integration parameters, For differential parameters; This is the integral value of the error; This is the differential value of the error.

5. The simulation method for a six-degree-of-freedom robot hydraulic system based on AMESim according to claim 1, characterized in that, The hydraulic cylinder displacement and joint angle function (13) is calculated using Solidworks joint structure.

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