Force-Position Hybrid Control of a New Parallel Hexapod Robot for Drilling Holes on Fuselage Surface

2013 ◽  
Author(s):  
Xianchao Zhao ◽  
Yang Pan ◽  
Feng Gao
Keyword(s):  
Dynamic Model ◽  
Force Control ◽  
Parallel Mechanism ◽  
Control Method ◽  
Hybrid Control ◽  
Control Mode ◽  
Work Status ◽  
Legged Robot ◽  
Hexapod Robot ◽  
Robot Performance

In this paper, a new kind of 6-legged robot for drilling holes on the aircraft surface is presented. Each leg of the robot is a parallel mechanism with 3 degree of freedoms thus the robot includes totally 18 motors. Due to different work status, the control modes of these motors are also different and thus the force-position hybrid control method is applied. The kinematic and dynamic model is briefly introduced. Then the robot gait is discussed. After that hybrid control method is introduced: first the control mode of each motor should be determined, then the position or force control curves should be calculated. In the end of this paper, both virtual and real prototype of this robot is showed and the experiment result showed that the hybrid control method can significantly improve the robot performance.

A new six-parallel-legged walking robot for drilling holes on the fuselage

2013 ◽  
Vol 228 (4) ◽  
pp. 753-764 ◽  
Author(s):  
Yang Pan ◽  
Feng Gao
Keyword(s):  
Working Conditions ◽  
Parallel Mechanism ◽  
Position Control ◽  
Control Method ◽  
Control Mode ◽  
Legged Robot ◽  
Walking Robot ◽  
Kinematical Model ◽  
Prismatic Joints ◽  
Control Curves

In this paper, a new kind of six-parallel-legged robot is presented. It is designed for drilling holes on the aircraft surface. Each leg of the robot is a 3-DOF parallel mechanism with three chains: 1UP and 2UPS. The three prismatic joints are active joints and can be controlled either by position or by force. First, the task process and the gait plan are discussed and then, according to the requirement, the control method is introduced. After that, the mechanism topology patterns under different working conditions are studied and the control mode of each motor is determined. Then the kinematical model is built up, based on which the position control curves can be obtained. The simulation result shows that the robot can walk pretty well on the fuselage surface and that the actuation forces are quite smooth. Furthermore, the first prototype has been manufactured and some experiments such as walking and manipulation have been done.

Compliant Control for the Redundant Dual-Arm Live-Working Robot

2013 ◽  
Vol 459 ◽  
pp. 177-182
Author(s):  
Huan Bing Gao ◽  
Shou Yin Lu ◽  
Guo Hui Tian
Keyword(s):  
Dynamic Model ◽  
Force Control ◽  
Stiffness Matrix ◽  
Control Method ◽  
Total System ◽  
Kinematic Structure ◽  
Compliant Control ◽  
Dual Arm

Two arms are attached on the live-working robot for cooperating jobs and some task requiring larger stiffness such as pushing and butting when replacing cross arm or insulator. The different kinematic structure of this two arms brings many difficulties to get the dynamic model of the total system. This paper proposes a force control method to solve this problem. Two arms are considered as one arm firstly, then the general stiffness matrix is obtained. And based on the compliant relationship between the dual arms and the environment, the force control method for the exact force control is presented. The scheme is experimentally tested on the live-working robot, and the effectiveness and rapidity is validated .

Dynamic Analysis and Control Research of a 3-DOF Hydraulic Driven Parallel Mechanism

2020 ◽  
Vol 13 (2) ◽  
pp. 156-170
Author(s):  
Bing Zhang ◽  
Saike Jiang ◽  
Ziliang Jiang ◽  
Jiandong Li ◽  
Kehong Zhou ◽  
...  
Keyword(s):  
Control System ◽  
Dynamic Model ◽  
Control Strategy ◽  
Parallel Mechanism ◽  
Control Method ◽  
Simulation Method ◽  
Euler Method ◽  
Parallel Mechanisms ◽  
Rigid Body Dynamic ◽  
And Control

Background: The parallel mechanism is widely used in motion simulators, parallel machine tools, medical equipment and other fields. It has advantages of high rigidity, stable structure and high carrying capacity. However, the control strategy and control method are difficult to study because of the complexity of the parallel mechanism system. Objective: The purpose of this paper was to verify the dynamic model of a hydraulic driven 3-DOF parallel mechanism and propose a compound control strategy to broaden the bandwidth of the control system. Methods: The single rigid body dynamic model of the parallel mechanism was established by the Newton Euler method. The feed forward control strategy based on joint space control with inverse kinematic was designed to improve the bandwidth and control precision. The co-simulation method based on MATLAB / SIMULINK and ADAMS was adopted to verify the dynamics and control strategy. Results: The bandwidth of each degree of freedom in the 3-DOF parallel mechanism was used to expand about 10Hz and the amplitude error was controlled below 5%. Conclusion: Based on the designed dynamic model and composite control strategy, the controlled accuracy of the parallel mechanism is improved and the bandwidth of the control system is broadened. Furthermore, the improvements can be made in aspects of control accuracy and real-time performance to compose more patents on parallel mechanisms.

scholarly journals Trajectory Tracking Control Study of a New Parallel Mechanism with Redundant Actuation

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Haiqiang Zhang ◽  
Hairong Fang ◽  
Dan Zhang ◽  
Qi Zou ◽  
Xueling Luo
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Parallel Mechanism ◽  
Dynamic Models ◽  
Control Method ◽  
Hybrid Control ◽  
Virtual Work ◽  
Redundant Actuation ◽  
Trajectory Tracking Control ◽  
Control Scheme

Parallel mechanisms with redundant actuation are attracting numerous scholars’ research interest due to their inherent advantages. In this paper, an efficient trajectory tracking control scheme for the new redundantly actuated parallel mechanism by integrating force/position hybrid control with the combination of inertia feed-forward control and back propagation (BP) neural network PID control is proposed. The dynamic models including the joint space and task space are formulated explicitly in efficient and compact form by means of the principle of virtual work and d’Alembert formulations. The force/position hybrid control is implemented to perform trajectory tracking and optimize the driving force configuration in MATLAB/Simulink environment, before being applied to an actual parallel mechanism. The illustrative simulation results demonstrate that the force/position hybrid control scheme is available to provide good trajectory tracking performance. Simultaneously, the feasibility of the proposed control scheme is verified by comparison analysis with the aforementioned conventional control method.

scholarly journals Modal Decoupled Dynamics Feed-Forward Active Force Control of Spatial Multi-DOF Parallel Robotic Manipulator

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Xinjian Niu ◽  
Chifu Yang ◽  
Bowen Tian ◽  
Xiang Li ◽  
Junwei Han
Keyword(s):  
Control Strategy ◽  
Force Control ◽  
Parallel Mechanism ◽  
Control Method ◽  
Intelligent System ◽  
Joint Space ◽  
Active Force ◽  
Feed Forward ◽  
Electric Actuator ◽  
Active Force Control

According to the parallel mechanism theory, this paper proposes a novel intelligent robotic spine brace for the treatment of scoliosis. Nevertheless, this type of parallel mechanism has the following disadvantages: strong dynamic coupling in task space or joint space, adverse effect of system’s gravity, and lower response frequency in roll and pitch orientations, which seriously affect the performance of the system. In order to solve those boring problems, this paper presents a novel active force control structure, modal space dynamic feed-forward (MSDF) force control strategy. Besides, this paper expresses the intelligent robotic brace system model including the dynamic and kinematic models and the electric actuator model with Kane strategy. The stability of the intelligent system with the novel control strategy is proved. In order to evaluate the performance of the presented MSDF force control method, this paper builds the parallel mechanism experimental platform. It can be seen from experimental results that the proposed motion control method solves these boring problems well.

Kinematical Model and Topology Patterns of a New 6-Parallel-Legged Walking Robot

2012 ◽  
Author(s):  
Pan Yang ◽  
Feng Gao
Keyword(s):  
Working Conditions ◽  
Force Control ◽  
Control Method ◽  
Design Method ◽  
Legged Robot ◽  
Walking Robot ◽  
Actuation Force ◽  
And Topology ◽  
Kinematical Model ◽  
The Relationship

In this paper, a new kind of 6-legged robot is presented. It was designed for drilling holes on the aircraft surface. Each leg of the robot is a 3-DOF parallel mechanism and the actuation can be controlled both by position and force. The mechanism design method of the robot is discussed. The relationship between control method and motion topology under different working conditions is studied. The kinematical model is built, based on which the motion plan are made. The control method is position-force control, so the calculation of actuation force is done. Finally, the simulation result is showed: the robot can drill on the fuselage surface successfully and the position-force control method can improve its performance a lot.

Dynamic Analysis and Simulation of a 1-DOF Driven by a Parallel Force/Velocity Actuator (PFVA)

2007 ◽  
Author(s):  
Dinesh Rabindran ◽  
Delbert Tesar
Keyword(s):  
Numerical Simulation ◽  
Dynamic Model ◽  
Force Control ◽  
Gear Train ◽  
Control Mode ◽  
Velocity Control ◽  
Dynamic Coupling ◽  
Force And Motion ◽  
Prime Movers ◽  
Force Velocity

Some work has been done to try to combine force control and velocity control capability into the same actuator design. The objective in trying to incorporate two fundamentally distinct resources (force and motion priorities) into the same actuator is to obtain an expanded spectrum of dynamic responses at the output of the system so that the system may (ideally) operate in pure force control mode or pure velocity control mode or a combination of these modes. Presented in this paper is a design that combines two fundamentally distinct actuators (one using low reduction or even direct drive, which we will call a Force Actuator (FA) and the other with a high reduction gear train that we will refer to as a Velocity Actuator (VA)). The premise of this work is that we could obtain a variety of responses at the system’s output by integrating separate force and motion priorities (Parallel Force/Velocity Actuator) within the same system in-parallel and dynamically “mixing” their contributions. We conceptually describe a Parallel Force/Velocity Actuator (PFVA) based on a Dual-Input-Single-Output (DISO) epicyclic gear train. We then present a dynamic model formulation for a non-linear 1-DOF mechanical system (Slider-Crank Mechanism) that uses a PFVA at the input. Using this dynamic model, we present a numerical simulation. The numerical simulation focuses on two issues, (a) effect of the relative scale change (ρ) between the two inputs on the torques at the two prime-movers and (b) effect of ρ on the dynamic coupling between the inputs. It was observed that as the relative scale change (represented by ρ) was decreased (i.e. the sub-systems tend towards behaving as “equal” systems) the dynamic coupling between the systems increased. In the study of the effect of ρ on the inertia and static torques at the prime-movers, it was noticed that they follow inverse trends.

Hybrid BTT/STT missile autopilot design

2017 ◽  
Vol 89 (6) ◽  
pp. 809-814
Author(s):  
Chengchao Bai ◽  
Fei Lu ◽  
Xibao Xu
Keyword(s):  
Nonlinear Dynamic ◽  
Control Method ◽  
Hybrid Control ◽  
Control Mode ◽  
Dynamic Inversion ◽  
Frequency Noise ◽  
Content Type ◽  
Hybrid Controller ◽  
Nonlinear Dynamic Inversion ◽  
Btt Missile

Purpose Traditional skid-to-turn (STT) missile control mode is adopted mostly, but with the improvement of requirements for mobility and the emergence of new aerodynamic layout, a bank-to-turn (BTT) control mode gradually shows a greater advantage. However, the BTT missile also has certain defects, for example, when attacking against a maneuvering target and at the last section of guidance, the maximum lifting surface position of the missile needs to be adjusted frequently, thereby increasing the difficulty of control as well as introducing high-frequency noise. Design/methodology/approach Based on respective characteristics of the two control modes, this paper puts forward a hybrid autopilot design method based on nonlinear dynamic inversion. Firstly, the method converts overload instructions into corresponding angle instructions through the design of hybrid control guidance logic; secondly, based on the nonlinear dynamic inversion algorithm and combined with the fast-changing circuit/slowly changing circuit, a hybrid controller is designed; finally, combined with the missile mathematical model and actuator, it forms a autopilot design closed loop. Findings The simulation result shows that the non-linear dynamic inverse-based BTT/STT hybrid controller can input a track command well, normal overload and roll angle tracking performance have more advantages than the hybrid controller designed on the basis of classical control method in terms of overshooting and hysteretic characteristics. Originality/value The paper puts forward a new BTT/STT hybrid control method which has both the high mobile ability of the BTT missile and the precise control ability of the STT missile, which can adapt to the more complicated fighting environment. And, the method can effectively weaken the impact of the transformation of the control mode on the system.

scholarly journals Coordinated compliance control of dual-arm robot astronaut for payload operation

2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110128
Author(s):  
Bingshan Hu ◽  
Lei Yan ◽  
Liangliang Han ◽  
Hongliu Yu
Keyword(s):  
Force Control ◽  
Position Control ◽  
Control Method ◽  
Constraint Equation ◽  
Control Mode ◽  
Control Methods ◽  
Compliance Control ◽  
Closed Chain ◽  
Dual Arm Robot ◽  
Dual Arm

Dual-arm robot astronaut has more general and dexterous operation ability than single-arm robot, and it can interact with astronaut more friendly. The robot will inevitably use both arms to grasp payloads and transfer them. The force control of the arms in closed chains is an important problem. In this article, the coordinated kinematic and dynamic equations of the dual-arm astronaut are established by considering the closed-chain constraint relationship. Two compliance control methods for dual-arm astronaut coordinated payload manipulating are proposed. The first method is called master–slave force control and the second is the shared force control. For the former, the desired path and operational force of the master arm should be given in advance and that of slave arm are calculated from the dual-arm robot closed-chain constraint equation. In the share control mode, the desired path and end operational force of dual arms are decomposed from the dual-arm robot closed-chain constraint equation directly and equally. Finally, the two control algorithms are verified by simulation. The results of analysis of variance of the simulation data show that the two control methods have no obvious difference in the accuracy of force control but the second control method has a higher position control accuracy, and this proves that the master–slave mode is better for tasks with explicit force distribution requirements and the shared force control is especially suitable for a high-precision requirement.

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