Development of an autonomous robotic system for beard shaving assistance of disabled people based on an adaptive force tracking impedance control

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406220984821 ◽

2021 ◽

pp. 095440622098482

Author(s):

Oladayo S Ajani ◽

Samy FM Assal

Keyword(s):

Impedance Control ◽

Environmental Parameters ◽

Robotic System ◽

Robotic Systems ◽

Full Potential ◽

Robotic Assistance ◽

Head Pose ◽

Detection And Tracking ◽

Control Scheme ◽

Force Tracking

Recently, people with upper arm disabilities due to neurological disorders, stroke or old age are receiving robotic assistance to perform several activities such as shaving, eating, brushing and drinking. Although the full potential of robotic assistance lies in the use of fully autonomous robotic systems, these systems are limited in design due to the complexities and the associated risks. Hence, rather than the shared controlled or active robotic systems used for such tasks around the head, an adaptive compliance control scheme-based autonomous robotic system for beard shaving assistance is proposed. The system includes an autonomous online face detection and tracking as well as selected geometrical features-based beard region estimation using the Kinect RGB-D camera. Online trajectory planning for achieving the shaving task is enabled; with the capability of online re-planning trajectories in case of unintended head pose movement and occlusion. Based on the dynamics of the UR-10 6-DOF manipulator using ADAMS and MATLAB, an adaptive force tracking impedance controller whose parameters are tuned using Genetic Algorithm (GA) with force/torque constraints is developed. This controller can regulate the contact force under head pose changing and varying shaving region stiffness by adjusting the target stiffness of the controller. Simulation results demonstrate the system capability to achieve beard shaving autonomously with varying environmental parameters that can be extended for achieving other tasks around the head such as feeding, drinking and brushing.

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Position/Force Tracking Impedance Control for Robotic Systems with Uncertainties Based on Adaptive Jacobian and Neural Network

Complexity ◽

10.1155/2019/1406534 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 13

Author(s):

Jinzhu Peng ◽

Zeqi Yang ◽

Tianlei Ma

Keyword(s):

Neural Network ◽

Impedance Control ◽

Tracking Error ◽

Tracking Performance ◽

Robotic Systems ◽

Position Tracking ◽

External Disturbances ◽

Outer Loop ◽

Control Scheme ◽

Force Tracking

In this paper, an adaptive Jacobian and neural network based position/force tracking impedance control scheme is proposed for controlling robotic systems with uncertainties and external disturbances. To achieve precise force control performance indirectly by using the position tracking, the control scheme is divided into two parts: the outer-loop force impedance control and the inner-loop position tracking control. In the outer-loop, an improved impedance controller, which combines the traditional impedance relationship with the PID-like scheme, is designed to eliminate the force tracking error quickly and to reduce the force overshoot effectively. In this way, the satisfied force tracking performance can be achieved when the manipulator contacts with environment. In the inner-loop, an adaptive Jacobian method is proposed to estimate the velocities and interaction torques of the end-effector due to the system kinematical uncertainties, and the system dynamical uncertainties and the uncertain term of adaptive Jacobian are compensated by an adaptive radial basis function neural network (RBFNN). Then, a robust term is designed to compensate the external disturbances and the approximation errors of RBFNN. In this way, the command position trajectories generated from the outer-loop force impedance controller can be then tracked so that the contact force tracking performance can be achieved indirectly in the forced direction. Based on the Lyapunov stability theorem, it is proved that all the signals in closed-loop system are bounded and the position and velocity errors are asymptotic convergence to zero. Finally, the validity of the control scheme is shown by computer simulation on a two-link robotic manipulator.

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Development and experimental evaluation of multi-fingered robot hand with adaptive impedance control for unknown environment grasping

Robotica ◽

10.1017/s0263574714002161 ◽

2014 ◽

Vol 34 (5) ◽

pp. 1168-1185 ◽

Cited By ~ 12

Author(s):

Ting Zhang ◽

Li Jiang ◽

Shaowei Fan ◽

Xinyu Wu ◽

Wei Feng

Keyword(s):

Position Control ◽

Sliding Mode ◽

Impedance Control ◽

Adaptive Estimation ◽

Environmental Parameters ◽

Parameters Estimation ◽

Friction Compensation ◽

Adaptive Sliding Mode ◽

Force Tracking ◽

Artificial Hand

SUMMARYThis paper presents adaptive impedance controllers with adaptive sliding mode friction compensation for anthropomorphic artificial hand. A five-fingered anthropomorphic artificial hand with multi-sensory and Field-Programmable Gate Arra (FPGA)-based control hardware and software architecture is designed to fulfill the requirements of the grasping force controller. In order to improve the force-tracking precision, the indirect adaptive algorithm was applied to estimate the parameters of the environment. The generalized momentum-based disturbance observer was applied to estimate the contact force from the torque sensor. Based on the sensors of the finger, an adaptive sliding mode friction compensation algorithm was utilized to improve the accuracy of the position control. The performances of the force-tracking impedance controller and position-based joint impedance control for the five-fingered anthropomorphic artificial hand are analyzed and compared in this paper. Furthermore, the performances of the force-tracking impedance controller with environmental parameters adaptive estimation and without environmental parameters estimation are analyzed and compared. Experimental results prove that accurate force-tracking and stable torque/force response under uncertain environments of unknown stiffness and position can be achieved with the proposed adaptive force-tracking impedance controller with friction compensation on five-finger artificial hand.

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A unified force control approach to autonomous underwater manipulation

Robotica ◽

10.1017/s026357470000309x ◽

2001 ◽

Vol 19 (3) ◽

pp. 255-266 ◽

Cited By ~ 17

Author(s):

Yong Cui ◽

Nilanjan Sarkar

Keyword(s):

Force Control ◽

Autonomous Underwater Vehicle ◽

Hybrid Control ◽

Impedance Control ◽

Underwater Vehicle ◽

Robotic System ◽

Control Approach ◽

Control Scheme ◽

Underwater Manipulation ◽

Six Degree Of Freedom

A unified force control scheme for an autonomous underwater robotic system is proposed in this paper. This robotic system is composed of a six degree-of-freedom autonomous underwater vehicle (AUV) and a robotic arm that is mounted on the AUV. A unified force control approach, which combines impedance control with hybrid position/force control by means of fuzzy switching to perform autonomous underwater manipulation, is presented in this paper. This controller requires a dynamic model of the underwater vehicle-manipulator system. However, it does not require any model of the environment and therefore will have the potential to be useful in underwater tasks where the environment is generally unknown. The proposed approach combines the advantages of impedance control with hybrid control so that both smooth contact transition and force trajectory tracking can be achieved. In the absence of any functional autonomous underwater vehicle-manipulator system that can be used to verify the proposed controller, extensive computer simulations are performed and the results are presented in the paper.

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Impedance with Finite-Time Control Scheme for Robot-Environment Interaction

Mathematical Problems in Engineering ◽

10.1155/2020/2796590 ◽

2020 ◽

Vol 2020 ◽

pp. 1-18 ◽

Cited By ~ 1

Author(s):

Heyu Hu ◽

Xiaoqi Wang ◽

Lerui Chen

Keyword(s):

Finite Time ◽

Impedance Control ◽

Tracking Performance ◽

Position Tracking ◽

Environment Interaction ◽

Robot System ◽

Outer Loop ◽

Time Control ◽

Control Scheme ◽

Force Tracking

For the robot system with the uncertain model and unknown environment parameters, a control scheme combining impedance and finite time is proposed. In order to obtain accurate force control performance indirectly by using position tracking, the control scheme is divided into two parts: an outer loop for force impedance control and an inner loop for position tracking control. In the outer loop, in order to eliminate the force tracking error quickly, the impedance control based on force is adopted; when the robot contacts with the environment, the satisfactory force tracking performance can be obtained. In the inner loop, the finite-time control method based on the homogeneous system is used. Through this method, the desired virtual trajectory generated by the outer loop can be tracked, and the contact force tracking performance can be obtained indirectly in the direction of force. This method does not need the dynamics model knowledge of the robot system, thus avoiding the online real-time calculation of the inverse dynamics of the robot. The unknown uncertainty and external interference of the system are obtained online by using the time-delay estimation, and the control process is effectively compensated, so the algorithm is simple, the convergence speed is fast, and the practical application is easy. The theory of finite-time stability is used to prove that the closed-loop system is finite-time stable, and the effectiveness of the algorithm is proved by simulations.

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Hybrid Force Tracking Impedance Control-Based Autonomous Robotic System for Tooth Brushing Assistance of Disabled People

IEEE Transactions on Medical Robotics and Bionics ◽

10.1109/tmrb.2020.3030317 ◽

2020 ◽

Vol 2 (4) ◽

pp. 649-660

Author(s):

Oladayo S. Ajani ◽

Samy F. M. Assal

Keyword(s):

Impedance Control ◽

Robotic System ◽

Tooth Brushing ◽

Disabled People ◽

Force Tracking

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Suppress Vibration on Robotic Polishing with Impedance Matching

Actuators ◽

10.3390/act10030059 ◽

2021 ◽

Vol 10 (3) ◽

pp. 59

Author(s):

Junjie Dai ◽

Chin-Yin Chen ◽

Renfeng Zhu ◽

Guilin Yang ◽

Chongchong Wang ◽

...

Keyword(s):

Contact Force ◽

Force Control ◽

Impedance Control ◽

Impedance Matching ◽

Industrial Robots ◽

Contact Phase ◽

Dynamic Tracking ◽

Force Tracking ◽

The Difference ◽

End Effectors

Installing force-controlled end-effectors on the end of industrial robots has become the mainstream method for robot force control. Additionally, during the polishing process, contact force stability has an important impact on polishing quality. However, due to the difference between the robot structure and the force-controlled end-effector, in the polishing operation, direct force control will have impact during the transition from noncontact to contact between the tool and the workpiece. Although impedance control can solve this problem, industrial robots still produce vibrations with high inertia and low stiffness. Therefore, this research proposes an impedance matching control strategy based on traditional direct force control and impedance control methods to improve this problem. This method’s primary purpose is to avoid force vibration in the contact phase and maintain force–tracking performance during the dynamic tracking phase. Simulation and experimental results show that this method can smoothly track the contact force and reduce vibration compared with traditional force control and impedance control.

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