Control Simulations for a Stewart Platform Compensator Mounted on Moving Base

2019 ◽  
Author(s):  
Takeyuki Ono ◽  
Ryosuke Eto ◽  
Junya Yamakawa ◽  
Hidenori Murakami
Keyword(s):  
Time Delay ◽  
Sliding Mode ◽  
Equations Of Motion ◽  
Base Plate ◽  
Medical Application ◽  
Stewart Platform ◽  
Hybrid Controller ◽  
Resolved Acceleration Control ◽  
Moving Base ◽  
Input Time

Abstract In this paper, utilizing the analytical equations of motion for a base-moving Stewart platform, we design an active wave compensation system for a surgery table installed on the top plate of a Stewart platform in a ship. In our medical application, the base plate of a Stewart platform moves with the motion of the ship. For a base-moving Stewart platform, we presented analytical equations of motion in matrix form in the paper: IMECE2018-87253. The objective of the platform is to compensate the pitching, rolling, and heaving motions of the ship (with respect to an inertial coordinate system). As control methods for the nonlinear system, we employ a hybrid controller combining resolved acceleration control with H∞ control, and integral sliding mode control (ISMC). The ISMC with input time delay is also designed with a state predictor, which includes a ship motion predictor utilizing an autoregressive model. Finally, to assess the control performance and robustness for the system with uncertainties, numerical simulations are presented. In addition, the simulation results of the predictor based ISMC for the system with input time delay are illustrated showing the effectiveness of the controller.

Development of Equations of Motion for a Stewart Platform Under Prescribed Mount Motion

2018 ◽  
Author(s):  
Takeyuki Ono ◽  
Ryosuke Eto ◽  
Junya Yamakawa ◽  
Hidenori Murakami
Keyword(s):  
Rigid Body ◽  
Virtual Work ◽  
Equations Of Motion ◽  
Base Plate ◽  
Stewart Platform ◽  
Euler Method ◽  
Moving Frame ◽  
Real Time Control ◽  
Precise Positioning ◽  
Time Control

Analytical equations of motion are critical for real-time control of translating manipulators, which require precise positioning of various tools for their mission. Specifically, when manipulators mounted on moving robots or vehicles perform precise positioning of their tools, it becomes economical to develop a Stewart platform, whose sole task is stabilizing the orientation and crude position of its top table, onto which various precision tools are attached. In this paper, analytical equations of motion are developed for a Stewart platform whose motion of the base plate is prescribed. To describe the kinematics of the platform, the moving frame method, presented by one of authors [1,2], is employed. In the method the coordinates of the origin of a body attached coordinate system and vector basis are expressed by using 4 × 4 frame connection matrices, which form the special Euclidean group, SE(3). The use of SE(3) allows accurate description of kinematics of each rigid body using (relative) joint coordinates. In kinetics, the principle of virtual work is employed, in which system virtual displacements are expressed through B-matrix by essential virtual displacements, reflecting the connection of the rigid body system [2]. The resulting equations for fixed base plate reduce to those for the top plate, obtained by the Newton-Euler method. A main result of the paper is the analytical equations of motion in matrix form for dynamics analyses of a Stewart platform whose base plate moves. The control applications of those equations will be deferred to subsequent publications.

scholarly journals FUZZY SLIDING MODE CONTROL OF A STRUCTURE BASED ON HEDGE ALGEBRAS CONTAINING INPUT TIME DELAY

2019 ◽  
Vol 57 (4) ◽  
pp. 513
Author(s):  
Le Hai Bui ◽  
Anh Tung Le ◽  
Binh Van Bui ◽  
Hoan Thai Tat Nguyen
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Fuzzy Controller ◽  
Sliding Mode ◽  
Control Force ◽  
Maximum Displacement ◽  
Absolute Acceleration ◽  
Mode Control ◽  
Input Time ◽  
The Impact

In this paper, the authors present the sliding mode control problem of a structure using hedge-algebras-based fuzzy controller considering the impact of time delay (de-sHAC). Controlled model is a structure subjected to earthquake excitations. Numerical simulations are implemented in order to show advantages of the proposed controller. Obtained results include: variation of maximum displacement and maximum absolute acceleration versus time delay; time responses of displacement, absolute acceleration and control force of the structure in the uncontrolled case, the controlled case using the hedge-algebras-based fuzzy controller with input time delay (de-HAC) and the de-sHAC.

scholarly journals Observer-Based Coordinated Control for Blended Braking System with Actuator Delay

Actuators ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 193
Author(s):  
Wenfei Li ◽  
Huiyun Li ◽  
Chao Huang ◽  
Kun Xu ◽  
Tianfu Sun ◽  
...  
Keyword(s):  
Time Delay ◽  
Sliding Mode ◽  
Coordinated Control ◽  
Time Delay Estimation ◽  
Smith Predictor ◽  
Braking System ◽  
Single Output ◽  
Braking Torque ◽  
Input Time ◽  
Friction Braking System

The coordinated control of a blended braking system is always a difficult task. In particular, blended braking control becomes more challenging when the braking actuator has an input time-delay and some states of the braking system cannot be measured. In order to improve the tracking performance, a coordinated control system was designed based on the input time-delay and state observation for a blended braking system comprising a motor braking system and friction braking system. The coordinated control consists of three parts: Sliding mode control, a multi-input single-output observer, and time-delay estimation-based Smith Predictor control. The sliding mode control is used to calculate the total command braking torque according to the desired braking performance and vehicle states. The multi-input single-output observer is used to simultaneously estimate the input time-delay and output braking torque of the friction braking system. With time-delay estimation-based Smith Predictor control, the friction braking system is able to effectively track the command braking torque of the friction braking system. The tracking of command braking torque is realized through the coordinated control of the motor braking system and friction braking system. In order to validate the effectiveness of the proposed approach, numerical simulations on a quarter-vehicle braking model were performed.

Dynamic Modeling and Analysis for a Planar Three Degrees-of-Freedom Manipulator Under Prescribed Mount Motion

2019 ◽  
Author(s):  
Takeyuki Ono ◽  
Ryosuke Eto ◽  
Junya Yamakawa ◽  
Hidenori Murakami
Keyword(s):  
Dynamic Modeling ◽  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Virtual Work ◽  
Equations Of Motion ◽  
Base Plate ◽  
Moving Frame ◽  
Parallel Plates ◽  
Modeling And Analysis ◽  
Three Degrees Of Freedom

Abstract This paper presents dynamic modeling of a planar, three degrees-of-freedom manipulator consisting of two parallel plates, referred to as top and base plates, which are connected by three actuated legs. When a sensitive equipment is carried by a moving robot or vehicle, it becomes necessary to mount the equipment on a platform which achieves precise positioning for stabilization. The objectives of this paper are to derive analytical equations of motion and apply them to control simulations on the stabilizing planar manipulator. In the derivation of analytical equations of motion, the moving frame method is utilized to describe the kinematics of the two-dimensional multibody system. For the manipulator system comprised of jointed bodies, a graph tree is utilized, which visually illustrates how the constituent bodies are connected to each other. For kinetics, the principle of virtual work is employed to derive the analytical equations of motion for the manipulator system. The resulting equations of motion are used to numerically assess the performance of a sliding mode controller (SMC) to stabilize the top plate from the motion of the translating and rotating base plate. In the numerical simulation, the SMC is compared with a simple PID controller to evaluate both the tracking performance and robustness.

Global Robust Sliding Mode Tracking Control for Helicopter with Input Time Delay

2013 ◽  
Vol 846-847 ◽  
pp. 434-437 ◽  
Author(s):  
Ling Cai ◽  
Fu Yang Chen ◽  
Fei Fei Lu
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Sliding Surface ◽  
State Variables ◽  
Mode Control ◽  
Mode Function ◽  
Control Scheme ◽  
Input Time ◽  
Integral Sliding Surface

In this paper, a global sliding mode control scheme is proposed for a helicopter with input time delay and disturbance. We proposed a new method for integral sliding surface. By the design of dynamic nonlinear sliding mode function, the controller has the advantage of eliminating the reaching movement of traditional sliding mode control, overcoming the effect of the disturbance and time delay. The system state variables reached the sliding surface at the very beginning by means of designing a dynamic nonlinear sliding mode function, and moved to the expected state under the control of control law. The efficiency of the proposed method is demonstrated by simulation results.

Robust Optimal Sliding Mode Control for Systems with Input Time Delay

2003 ◽  
Vol 36 (11) ◽  
pp. 151-156
Author(s):  
M. Basin ◽  
J. Rodrigez Gonzalez ◽  
L. Fridman
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Mode Control ◽  
Input Time
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