Research On Active Compliance Control Of Hydraulic Heavy-duty Manipulator For Contacting Task

As a type of robot,hydraulic heavy-duty manipulators are now widely used in rescue,military,aerospace,deep-sea operations,and industrial production.For a fully hydraulic and heavy-duty mechanical arm with a large flow rate,multiple degrees of freedom and a complex configuration,first of all,in terms of the design of the cross-joint tarpaulin pipe,it still has four problems: incompactness,unsightly,unreliable,and unintegrated;secondly,in the existing In active compliance control,the acquisition and perception of the dynamic contact force between the work object and the robotic arm mostly relies on the "delicate" force/torque sensor.However,because the output power and inertia of hydraulic heavy-duty manipulators are generally larger,the impact at the moment of hard contact is greater,and the force/torque sensor is used to sense the contact force,which is more likely to exceed the force/torque sensor range and cause the sensor to be damaged,which has a serious impact The research results of the active compliance control of the heavy-duty hydraulic manipulator came out of the laboratory and applied to the fine work site.On the other hand,the traditional position-based impedance active compliance control strategy has a fixed target impedance parameter,and cannot reasonably match the target impedance parameter according to the dynamic interaction force characteristics with the working object.Therefore,it guarantees the performance of high outer loop force tracking at the same time.Can not take into account the trajectory tracking performance in free space and avoid the strong impact of the higher contact transition stage,and cannot have high adaptability to non-structural objects with different stiffness,so the active compliance control performance is poor.Based on the above three problems,this article focuses on the following research work:(1)In view of the difficulty of hydraulic oil circuit arrangement across rotating joints due to its complex configuration characteristics with large flow and multiple degrees of freedom,the research object in this paper first designed and developed a heavy-duty pitch joint with slip ring function and a slip ring.The heavy-duty rotating heavy-duty joint with ring function,and the use of statics analysis software to complete the static school core work of its key parts;then,the design,development,assembly and commissioning of the seven-degree-of-freedom fully hydraulic heavy-duty manipulator On the basis of the design test,the design test completed the heavy load and dynamic sealing performance test work of the designed joint,and solved the problem that the hydraulic heavy-duty manipulator with a large flow rate and multi-joint complex configuration is not compact,unsightly,and unreliable.Does not integrate engineering issues.(2)Established the mathematical model of the forward and inverse kinematics of the plane three-degree-of-freedom hydraulic heavy-duty manipulator and the position control of the valve-controlled servo cylinder hydraulic drive unit,thus completing the position control of the inner-loop position control of the hydraulic heavy-duty manipulator.Part of the derivation of the entire transfer function.(3)According to the structural parameters of the built hydraulic heavy-duty manipulator model,firstly,the precise dynamics mathematical theory derivation was completed,and the relevant structural parameters were built up the Simulink/AMESim electro-hydraulic joint simulation platform of the hydraulic heavy-duty mechanical plane with three degrees of freedom.And based on this platform,the realization of the terminal force online soft-sensing algorithm simulation module was completed.Finally,the test device was designed and the test plan was formulated.The experimental verification of the terminal force online soft-sensing was completed on the physical experiment platform,and achieved high Soft measurement accuracy.(4)Research the active compliance control of hydraulic heavy-duty manipulator.Based on the position control of the position-type impedance compliance control inner loop of the hydraulic heavy-duty manipulator,the traditional impedance control outer loop is added to the AMESim/Simulink electro-hydraulic co-simulation platform of the hydraulic heavy-duty machinery,and the traditional position is analyzed through simulation research.The existing problems of the type impedance control method.It is found that the traditional position-based impedance control has the fixed active compliance control parameters,which can not take into account the poor tracking performance of free space space trajectory while maintaining force tracking,the strong impact during the contact transition stage and the difficulty of matching the damping parameters of different rigid contact objects.As a result,a fuzzy position-based variable impedance active compliance control strategy based on the system observer is proposed,and simulations verify that this strategy effectively improves the active compliance control effect of the traditional impedance compliance control contact operation.