Digital Motion Control and Profile Planning for Pneumatic Servos

1992 ◽  
Vol 114 (4) ◽  
pp. 634-640 ◽  
Author(s):  
J. Pu ◽  
R. H. Weston ◽  
P. R. Moore
Keyword(s):  
Motion Control ◽  
Transient Behavior ◽  
Performance Characteristics ◽  
Motion Controller ◽  
Operating Characteristics ◽  
Servo Systems ◽  
Pneumatic Actuators ◽  
Control Scheme ◽  
Conventional Methods ◽  
The Stability

This paper considers the use of “profile-planning” to (i) improve/optimize certain performance characteristics of pneumatic servos and (ii) simplify procedures associated with their tuning. The underlying approach is to preplan the transient behavior of the system thereby generating an appropriate command profile. To assist in applying this technique to the control of air-powered servo-systems, the paper highlights important knowledge derived previously with regard to the stability and operating characteristics of pneumatic drives. Preliminary rules for conducting such planning are then proposed with reference to a series of experimental observations. This approach can be employed to significantly reduce or prevent overshoot and instability of servo-driven pneumatic actuators (cylinders in particular) which are difficult to overcome by using conventional methods. At the same time, increased operating speeds and improved positioning can be attained. The proposed control scheme has been implemented in prototype form through using a proprietary programmable motion controller which incorporates software mechanism for generating gearbox and cam-like motion profiles.

scholarly journals Control of an Omnidirectional UAV for Transportation and Manipulation Tasks

2021 ◽  
Vol 11 (22) ◽  
pp. 10991
Author(s):  
Michelangelo Nigro ◽  
Francesco Pierri ◽  
Fabrizio Caccavale
Keyword(s):  
Motion Control ◽  
Mechanical Design ◽  
Contact Forces ◽  
Motion Controller ◽  
Joint Torques ◽  
External Loop ◽  
Control Scheme ◽  
Aerial Vehicle ◽  
The Stability ◽  
The Moment

This paper presents a motion control scheme for a new concept of omnidirectional aerial vehicle for transportation and manipulation tasks. The considered aerial platform is a novel quadrotor with the capability of providing multi-directional thrust by adding an actuated gimbal mechanism in charge of modifying the orientation of the frame on which the four rotors are mounted. The above mechanical design, differently from other omnidirectional unmanned aerial vehicles (UAVs) with tilted propellers, avoids internal forces and energy dissipation due to non-parallel propellers’ axes. The proposed motion controller is based on a hierarchical two-loop scheme. The external loop computes the force to be applied to the vehicle and the reference values for the additional joints, while the inner loop computes the joint torques and the moment to be applied to the multirotor. In order to make the system robust with respect to the external loads, a compensation of contact forces is introduced by exploiting the estimate provided by a momentum based observer. The stability of the motion control scheme is proven via Lyapunov arguments. Finally, two simulation case studies prove the capability of the omnidirectional UAV platform to track a 6-DoFs trajectory both in free motion and during a task involving grasping and transportation of an unknown object.

scholarly journals Reuse of Exhausted Air from Multi-Actuator Pneumatic Control Systems

Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 125
Author(s):  
Milan Šešlija ◽  
Vule Reljić ◽  
Dragan Šešlija ◽  
Slobodan Dudić ◽  
Nikolina Dakić ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Control Systems ◽  
Dynamic Behavior ◽  
Motion Control ◽  
Energy Savings ◽  
Compressed Air ◽  
Pneumatic System ◽  
Pneumatic Actuators ◽  
Pneumatic Control ◽  
Control Scheme

In order to improve the energy efficiency of multi-actuator pneumatic systems, a control scheme for the recovery of exhausted compressed air is designed and studied herein. This paper explains the procedure for the development of the balanced operation of a multi-actuator pneumatic system through the collection and reuse of exhausted compressed air. Compared with traditional motion control of pneumatic actuators, significant energy savings can be achieved, while the dynamic behavior of the cylinders from which the exhausted air is collected is maintained.

A computationally efficient adaptive robust control scheme for a quad-rotor transporting cable-suspended payloads

2021 ◽  
pp. 095441002110136
Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  
Keyword(s):  
Robust Control ◽  
Fractional Order ◽  
Sliding Mode ◽  
Adaptive Robust Control ◽  
Computationally Efficient ◽  
Control Scheme ◽  
Control Schemes ◽  
Adaptive Laws ◽  
Unknown Disturbances ◽  
The Stability

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.

Adaptive attitude-tracking control of spacecraft considering on-orbit refuelling

2020 ◽  
pp. 014233122097313
Author(s):  
Yiqi Xu
Keyword(s):  
Tracking Control ◽  
Closed Loop ◽  
Closed Loop System ◽  
Tracking Errors ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Inertia Model ◽  
And Performance ◽  
Attitude Tracking Control ◽  
The Stability

This paper studies the attitude-tracking control problem of spacecraft considering on-orbit refuelling. A time-varying inertia model is developed for spacecraft on-orbit refuelling, which actually includes two processes: fuel in the transfer pipe and fuel in the tank. Based upon the inertia model, an adaptive attitude-tracking controller is derived to guarantee the stability of the resulted closed-loop system, as well as asymptotic convergence of the attitude-tracking errors, despite performing refuelling operations. Finally, numerical simulations illustrate the effectiveness and performance of the proposed control scheme.

Zeroing dynamics based motion control scheme for parallel manipulators

2017 ◽  
Vol 53 (2) ◽  
pp. 74-75 ◽  
Author(s):  
Yunong Zhang ◽  
Liangyu He ◽  
Shuai Li ◽  
Dechao Chen ◽  
Yaqiong Ding
Keyword(s):  
Motion Control ◽  
Parallel Manipulators ◽  
Control Scheme

Chaos Anti-Synchronization between Chen System and Lu System

2014 ◽  
Vol 631-632 ◽  
pp. 710-713 ◽  
Author(s):  
Xian Yong Wu ◽  
Hao Wu ◽  
Hao Gong
Keyword(s):  
Chaotic Systems ◽  
Sufficient Conditions ◽  
Lyapunov Theory ◽  
State Variables ◽  
Chen System ◽  
System Parameters ◽  
Control Scheme ◽  
Error Dynamics ◽  
The Stability ◽  
Different Chaotic Systems

Anti-synchronization of two different chaotic systems is investigated. On the basis of Lyapunov theory, adaptive control scheme is proposed when system parameters are unknown, sufficient conditions for the stability of the error dynamics are derived, where the controllers are designed using the sum of the state variables in chaotic systems. Numerical simulations are performed for the Chen and Lu systems to demonstrate the effectiveness of the proposed control strategy.

scholarly journals Adaptive-Neural-Network-Based Shape Control for a Swarm of Robots

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Xuejing Lan ◽  
Zhenghao Wu ◽  
Wenbiao Xu ◽  
Guiyun Liu
Keyword(s):  
Neural Network ◽  
Nonlinear Dynamics ◽  
Shape Control ◽  
Formation Control ◽  
Adaptive Neural Network ◽  
Multirobot System ◽  
Control Scheme ◽  
Narrow Space ◽  
The Stability ◽  
Unknown Nonlinear Dynamics

This paper considers the region-based formation control for a swarm of robots with unknown nonlinear dynamics and disturbances. An adaptive neural network is designed to approximate the unknown nonlinear dynamics, and the desired formation shape is achieved by designing appropriate potential functions. Moreover, the collision avoidance, velocity consensus, and region tracking are all considered in the controller. The stability of the multirobot system has been demonstrated based on the Lyapunov theorem. Finally, three numerical simulations show the effectiveness of the proposed formation control scheme to deal with the narrow space, loss of robots, and formation merging problems.

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