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

Abstract

The invention discloses a six-degree-of-freedom robot hydraulic system simulation method based on AMESim, and belongs to the technical field of six-degree-of-freedom robot hydraulic system simulation. The method comprises the following steps: S1, constructing a hydraulic drive unit simulation model in AMESim; s2, constructing a hydraulic oil source; s3, a Submodel mode in the AMESim is utilized, and a Premier submodel function is used for endowing the sub-model; s4, respectively setting parameter values of the hydraulic driving unit simulation model in the S3 and each element in the hydraulic oil source according to actual parameters; and S5, based on the model obtained in the S4, a simulation mode is entered by utilizing a simulation mode, simulation of the six-degree-of-freedom robot hydraulic system based on AMESim is completed, and a change curve of a target joint rotation angle signal and an actual joint rotation angle is obtained. According to the invention, each hydraulic driving joint unit of the six-degree-of-freedom robot can be simulated, so that the movement condition of each driving joint unit can be mastered, and a foundation is laid for movement and accurate control of a hydraulic system of the six-degree-of-freedom robot.

Description

Technical Field

[0001] The invention belongs to the technical field of six-degree-of-freedom robot hydraulic system simulation, and in particular relates to a six-degree-of-freedom robot hydraulic system simulation method based on AMESim. Background Art

[0002] The six-degree-of-freedom hydraulic robot (referred to as the six-degree-of-freedom robot in this invention) has been widely used in many fields such as industrial manufacturing, mining construction, medical assistance, logistics and warehousing due to its advantages such as high load capacity, flexibility, precision and adaptability. Especially in large-scale resource mining, cutting, transporting heavy objects and other tasks, the hydraulically driven mechanical arm can efficiently complete the task.

[0003] However, at present, most six-DOF hydraulic robots use hydraulic motors to drive joint rotation, while there are fewer robots that use a combination of hydraulic cylinders and hydraulic motors to drive joint rotation. Using AMESim as a simulation platform can build hydraulic systems more quickly and analyze simulation results more intuitively. Summary of the invention

[0004] The purpose of the present invention is 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 of the present invention has the ability to perform hydraulic simulation on each driving joint unit of the six-degree-of-freedom robot so as to grasp the motion of each driving joint unit, thus laying a foundation for the motion and precise control of the six-degree-of-freedom robot hydraulic system.

[0005] The specific technical solutions adopted by the present invention are as follows:

[0006] The present invention 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 drive unit simulation model of the hydraulic system of the six-degree-of-freedom robot is constructed in AMESim; the hydraulic drive unit simulation model includes a pitch joint part and a rotation 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 rotation joint part includes a waist rotation joint unit and a terminal rotation joint unit;

[0008] S2: Based on the hydraulic drive unit simulation model described in S1, the hydraulic oil source of the six-DOF robot hydraulic system is constructed in AMESim;

[0009] S3: Using the Submodel mode in AMESim, use the Premier submodel function to assign the submodel of the six-DOF robot hydraulic system established in S1 and S2;

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

[0011] S5: Based on the result of S4, use the Simulation mode to enter the simulation mode, complete the simulation of the six-degree-of-freedom robot hydraulic system based on AMESim, and obtain the change curve of the target joint rotation angle signal and the actual joint rotation angle.

[0012] Preferably, the hydraulic oil source includes a cylinder, a filter, a motor, a hydraulic pump, a one-way valve and a relief valve; the parameters set in S4 include the cylinder oil pressure, the hydraulic pump displacement, the motor rated speed, the relief valve set pressure, and the filter and the one-way valve use the default values ​​of AMESim.

[0013] Preferably, the waist rotation joint unit and the terminal rotation joint unit are set up in the same manner, both including a three-position four-way electromagnetic reversing valve, a balancing valve, a cycloidal motor, a torque unit, an angle sensor and a PID controller; the parameters set in S4 include the cycloidal motor displacement, the torque value of the torque unit, and the PID controller parameters. The three-position four-way electromagnetic reversing valve, the balancing valve, and the angle sensor all use the default values ​​of AMESim.

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

[0015]

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

[0017] Preferably, 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 manner, all including 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, hydraulic cylinder displacement and joint angle function, load unit size, and the displacement sensor adopts the default value of AMESim.

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

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

[0020] (1) The method of the present invention realizes the construction of a hydraulic system for a six-degree-of-freedom robot, laying a foundation for the subsequent control of the six-degree-of-freedom robot;

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

[0022] (3) In the method of the present invention, the relationship between the hydraulic cylinder displacement and the joint angle is represented by functional relationship transformation, thereby achieving real-time feedback of the angle of each joint and increasing the authenticity and reliability of the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Shown is the basic structure of a six-degree-of-freedom robot;

[0024] Figure 2 Shown is the AMESim model of the hydraulic system of a six-DOF robot;

[0025] Figure 3 Shown is the hydraulic oil source in the AMESim model of the six-DOF robot hydraulic system;

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

[0027] Figure 5 Shown is the shoulder pitch joint unit in the AMESim model of the six-DOF robot hydraulic system;

[0028] Figure 6 The figure shows the angle variation curve of the waist rotation joint unit in the embodiment;

[0029] Figure 7 The figure shows the angle variation curve of the shoulder pitch joint unit in the embodiment;

[0030] Markings in the figure: cylinder 1, filter 2, motor 3, hydraulic pump 4, one-way valve 5, overflow valve 6, three-position four-way solenoid reversing valve 7, balance valve 8, cycloid 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 present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0032] The present invention provides a six-degree-of-freedom robot hydraulic system simulation method based on AMESim, and the method is specifically as follows:

[0033] S1: The hydraulic principle diagram of the hydraulic system of the six-degree-of-freedom robot constructed according to the actual working conditions of the six-degree-of-freedom robot, which is mainly divided into two parts: the hydraulic drive unit and the hydraulic oil source.

[0034] According to the three-dimensional model of the six-degree-of-freedom robot established in Solidworks, the hydraulic drive unit simulation model of the six-degree-of-freedom robot hydraulic system is constructed in AMESim. The hydraulic drive unit simulation model is mainly divided into two parts, namely the pitch joint part and the rotation joint part. Among them, the pitch joint part includes the shoulder pitch joint unit, the elbow pitch joint unit, the wrist vertical pitch joint unit and the wrist horizontal pitch joint unit, and the rotation joint part includes the waist rotation joint unit and the end rotation joint unit.

[0035] S2: Based on the S1 hydraulic drive unit simulation model, the 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 follows: Figure 1 As shown in the figure, the AMESim model of the hydraulic system of the six-degree-of-freedom robot is constructed as follows Figure 2 shown.

[0037] Specifically, Figure 3 As shown, the hydraulic oil source mainly includes two cylinders 1, two filters 2, a motor 3, a hydraulic pump 4, two one-way valves 5 and a relief valve 6. Among them, the motor 3 is connected to the hydraulic pump 4 in a transmission manner, the oil inlet end of the hydraulic pump 4 is connected to the first filter 2, the other port of the filter 2 is connected to the first cylinder 1, the oil outlet end of the hydraulic pump 4 is connected to the oil inlet end of the first one-way valve 5, and the oil outlet end of the first one-way valve 5 is connected to the relief valve 6; the second filter 2 and the second one-way valve 5 are connected in parallel, and both ends of the second filter 2 and the second one-way valve 5 are respectively connected to the outlet of the relief valve 6 and the second cylinder 1. The waist rotation joint unit and the end rotation joint unit are set in the same way, and both mainly include a three-position four-way electromagnetic reversing valve 7, a balancing valve 8, a cycloidal motor 9, a torque unit 10, an angle sensor 11 and a PID controller 12. In this embodiment, the waist rotation joint unit is as follows Figure 4As shown, the angle sensor 11 is connected to the cycloidal motor 9 to detect the actual rotation angle of the cycloidal motor 9; the torque unit 10 is connected to the angle sensor 11 to apply torque to the cycloidal motor 9; the error signal is obtained by comparing the signal value of the angle sensor 11 with the expected signal value, and 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 arranged in the same manner, and mainly include a hydraulic cylinder displacement and joint angle function 13, a displacement sensor 14, a load unit 15 and a hydraulic cylinder 16. In this embodiment, the shoulder pitch joint unit is as shown in FIG. 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 the 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] The PID controller 12 controls the joint angle based on the following mathematical model:

[0039]

[0040] Where u(t) is the controller output value; e(t) is the current error value; K p is the scale parameter, K i is the integration 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: Using the Submodel mode in AMESim, use the Premier submodel function to assign the submodel of the six-DOF robot hydraulic system established in S1 and S2.

[0042] S4: According to the actual parameters of the hydraulic system of the six-degree-of-freedom robot to be simulated, 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 are set respectively.

[0043] As a preferred embodiment of the present invention, the parameters set in S4 for the hydraulic oil source include the oil pressure of the cylinder 1, the displacement of the hydraulic pump 4, the rated speed of the motor 3, and the set pressure of the relief valve 6. The filter 2 and the one-way valve 5 use the default values ​​of AMESim. The parameters set in S4 for 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, and the three-position four-way electromagnetic reversing valve 7, the balance valve 8, and the angle sensor 11 all use the default values ​​of AMESim. The parameters set in S4 for 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, and the hydraulic cylinder displacement and joint angle function 13, the size of the load unit 15, and the displacement sensor 14 uses the default values ​​of AMESim. Among them, the hydraulic cylinder displacement and joint angle function 13 is calculated using the Solidworks joint structure.

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

[0045] In this embodiment, the angle variation curve of the waist rotation joint unit is as follows: Figure 6 As shown in the figure, the angle change curve of the shoulder pitch joint unit is as follows: Figure 7 As shown in the figure, it can be seen that the actual signal and the target signal have the same trajectory, good followability and small error, which means that the joint rotation angle can be accurately controlled.

[0046] The present invention can simulate each hydraulic drive joint unit of the six-degree-of-freedom robot so as to grasp the movement of each drive joint unit, thus laying a foundation for the movement and precise control of the hydraulic system of the six-degree-of-freedom robot.

[0047] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A six-degree-of-freedom robot hydraulic system simulation method based on AMESim, characterized in that: The details are as follows: S1: According to the three-dimensional model of the six-degree-of-freedom robot established in Solidworks, a hydraulic drive unit simulation model of the hydraulic system of the six-degree-of-freedom robot is constructed in AMESim; the hydraulic drive unit simulation model includes a pitch joint part and a rotation 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 rotation joint part includes a waist rotation joint unit and a terminal rotation joint unit; S2: Based on the hydraulic drive unit simulation model described in S1, the hydraulic oil source of the six-DOF robot hydraulic system is constructed in AMESim; S3: Using the Submodel mode in AMESim, use the Premier submodel function to assign the submodel of the six-DOF robot hydraulic system established in S1 and S2; S4: according to the actual parameters of the hydraulic system of the six-degree-of-freedom robot to be simulated, respectively set the simulation model of the hydraulic drive unit of the hydraulic system of the six-degree-of-freedom robot and the parameter values ​​of each component in the hydraulic oil source in S3; S5: Based on the result of S4, use the Simulation mode to enter the simulation mode, complete the simulation of the six-degree-of-freedom robot hydraulic system based on AMESim, and obtain the change curve of the target joint rotation angle signal and the actual joint rotation angle.

2. A six-degree-of-freedom robot hydraulic system simulation method based on AMESim according to claim 1, characterized in that: The hydraulic oil source comprises an oil cylinder (1), a filter (2), a motor (3), a hydraulic pump (4), a one-way valve (5) and a relief valve (6); the parameters set in S4 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 relief valve (6), and the filter (2) and the one-way valve (5) adopt the default values ​​of AMESim.

3. The method for simulating a hydraulic system of a six-degree-of-freedom robot based on AMESim according to claim 1, characterized in that: The waist rotation joint unit and the terminal rotation joint unit are set in the same manner, both including a three-position four-way electromagnetic reversing valve (7), a balancing 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 electromagnetic reversing valve (7), the balancing valve (8), and the angle sensor (11) all use the default values ​​of AMESim.

4. The AMESim-based six-degree-of-freedom robot hydraulic system simulation method according to claim 3, characterized in that: The PID controller (12) controls the joint angle based on the following mathematical model: Where u(t) is the controller output value; e(t) is the current error value; K p is the scale parameter, K i is the integration parameter, K d is the differential parameter; ∫e(t) is the integral value of the error; is the differential value of the error.

5. The AMESim-based six-degree-of-freedom robot hydraulic system simulation method according to claim 1, characterized in that: 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 manner, and all include a hydraulic cylinder displacement and joint angle function (13), a displacement sensor (14), a load unit (15) and a hydraulic cylinder (16); the parameters set in S4 include the maximum working pressure, stroke, cylinder diameter and piston rod diameter, working temperature range, and the hydraulic cylinder displacement and joint angle function (13), the load unit (15) size of the hydraulic cylinder (16); the displacement sensor (14) adopts the default value of AMESim.

6. The AMESim-based six-DOF robot hydraulic system simulation method according to claim 5, characterized in that: The hydraulic cylinder displacement and joint angle function (13) is obtained by calculating the joint structure using Solidworks.

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