Modeling and Trajectory Control of a Forklift-Like Wheeled Robot

2014 ◽  
Author(s):  
Ho-Hoon Lee
Keyword(s):  
Asymptotic Stability ◽  
Real Time ◽  
Dynamic Model ◽  
Dynamic Models ◽  
Trajectory Control ◽  
Control Law ◽  
Steering Control ◽  
Control Laws ◽  
Control Scheme ◽  
Trajectory Generator

In this paper, kinematic and dynamic models are derived for a forklift-like four-wheeled mobile robot, and then, based on the models, a new trajectory control scheme is designed and evaluated for the robot. The dynamic model, exhibiting non-minimum-phase characteristics, is derived by applying Lagrange’s equations and then the control law is design by using Lyapunov stability theorem and the loop shaping method. The proposed control scheme consists of a trajectory generator, a motion control law, and a steering control law. First, a real-time trajectory generator is designed based on the nonholonomic kinematic constraints of the robot, in which the reference driving speed and time rate of heading angle are computed in real time for a given desired trajectory of the robot. The proposed trajectory generator guarantees a local asymptotic stability. Next, motion and steering control laws are designed based on the dynamic model of the robot. The motion and steering control laws are used to control the robot speed and steering angle. The proposed control guarantees asymptotic stability of the trajectory control while keeping all internal signals bounded. Finally, the validity of the proposed control scheme is shown by realistic computer simulations with one sampling-time delay in the control loop.

A New Trajectory Control of a Car-Like Wheeled Robot

2012 ◽  
Author(s):  
Ho-Hoon Lee
Keyword(s):  
Real Time ◽  
Trajectory Control ◽  
Control Law ◽  
Steering Control ◽  
Control Laws ◽  
Driving Speed ◽  
Control Scheme ◽  
Heading Angle ◽  
Trajectory Generator ◽  
Mathematical Design

This paper proposes a trajectory control scheme for a car-like four-wheeled mobile robot. The proposed control scheme consists of a trajectory generator, a motion control law, and a steering control law. First, a real-time trajectory generator is designed based on the nonholonomic kinematic constraints of the robot, in which the reference driving speed and time rate of heading angle are computed in real time for a given desired trajectory of the robot. Next, motion and steering control laws are designed based on the dynamic model of the robot. The motion and steering control laws are used to control the robot speed and steering angle. Finally, the validity of the proposed control scheme is shown by realistic computer simulations with one sampling time delay in the control loop. In this study, the Lyapunov stability theorem and the loop shaping method are used as mathematical design tools. The proposed control guarantees asymptotic stability of the trajectory control while keeping all internal signals bounded. The proposed method of control design is much simpler than the back-stepping method.

Substructuring Dynamic Modeling and Active Vibration Control of a Smart Parallel Platform

2004 ◽  
Author(s):  
Xiaoyun Wang ◽  
James K. Mills
Keyword(s):  
Vibration Control ◽  
Dynamic Model ◽  
Motion Control ◽  
Dynamic Models ◽  
Active Vibration Control ◽  
System Dynamic ◽  
Control Law ◽  
Active Vibration ◽  
Parallel Platform ◽  
Simulation Results

A substructuring approach to derive dynamic models for closed-loop mechanisms is applied to model a flexible-link planar parallel platform with Lead Zirconate Titanate (PZT) transducers. The Lagrangian Finite Element (FE) formulation is used to model flexible linkages, in which translational and rotary degrees of freedom exist. Craig-Bampton mode sets are extracted from these FE models and then used to assemble the dynamic model of the planar parallel platform through the application of Lagrange’s equation and the Lagrange multiplier method. Electromechanical coupling models of surface-bonded PZT transducers with the host flexible linkages are introduced to the reduced order dynamic models of flexible linkages. The assembled system dynamic model with moderate model order can represent essential system dynamic behavior and maintain kinematic relationships of the planar parallel platform. A Proportional, Integral, and Derivative (PID) control law is used as the motion control law. Strain rate feedback (SRF) active vibration control is selected as the vibration control law. Motion control simulation results with active vibration control and simulation results without active vibration control are compared. The comparison shows the effectiveness of active vibration control.

On Aero Control Law Joined Compensatory PID for Glide down to Fixed Low Altitude System and Simulation Researches

2012 ◽  
Vol 198-199 ◽  
pp. 1021-1024
Author(s):  
De Hai Yu ◽  
Dong Cai Qu ◽  
Jian Hua Lu ◽  
Bin Wen Lu
Keyword(s):  
Control Law ◽  
Simple Analysis ◽  
Control Laws ◽  
Control Scheme ◽  
Improve Accuracy ◽  
Working Principle ◽  
Simulation Results ◽  
Low Altitude ◽  
Constant Altitude ◽  
And Control

In order to improve accuracy of constant altitude fly at low altitude and fly track of glide down to fixed altitude, aeroplane’s control scheme of glide down to fixed low altitude with PID compensatory link were designed. At the same time, the corresponding control laws had been designed. After simple analysis about working principle of the aeroplane’s control system, simulation researches were done to optimize designed control laws, so that achieving expectant requirement. Simulation results show that designed control scheme and control law were accurate and effective.

Approximate Dynamic Models of Manipulation Robots

Robotica ◽  
1991 ◽  
Vol 9 (3) ◽  
pp. 341-347 ◽  
Author(s):  
N. Djurović ◽  
M. Vukobratović
Keyword(s):  
Real Time ◽  
Dynamic Model ◽  
Relative Error ◽  
Dynamic Models ◽  
Approximate Model ◽  
Model Computation ◽  
Error Criterion ◽  
Manipulation Robots ◽  
Relative Error Criterion

SUMMARYIn this paper, the problem of real-time computation of a dynamic model of manipulator is considered. In order to decrease the number of operations for dynamic model computation, an approximate model is introduced. Also, a relative error criterion is proposed, which enables one to determine the computing periods of various parts of a dynamic model of manipulator.

Modeling and Control of a Horizontal Two-Link Rigid/Flexible Robot

2005 ◽  
Author(s):  
Ho-Hoon Lee
Keyword(s):  
Dynamic Model ◽  
Trajectory Tracking ◽  
Tracking Control ◽  
Trajectory Control ◽  
Distributed Parameter ◽  
Mathematical Tool ◽  
Flexible Robot ◽  
Trajectory Tracking Control ◽  
Modeling And Control ◽  
Control Scheme

This paper proposes a trajectory control scheme for a horizontal two-link rigid/flexible robot having a payload at the free end. First, a new distributed-parameter dynamic model, consisting of two ordinary differential equations and one partial differential equation, is derived using the extended Hamilton’s principle, and then a trajectory-tracking control scheme is designed based on the distributed-parameter dynamic model, where the Lyapunov stability theorem is used as a mathematical tool. The proposed control is a collocated control, free from the so-called spillover instability. The proposed control consists of a PD control for the rigid dynamics, a proportional control for the flexible dynamics, and feed forward and dynamics compensation. With only two joint actuators, the proposed trajectory control guarantees stability throughout the entire trajectory-tracking control and asymptotic stability at desired goal positions. The theoretical results have been evaluated with control experiments.

Controller Development for an Automotive Shape Memory Alloy Actuator

2007 ◽  
Author(s):  
Eric A. Williams ◽  
Mohammad Elahinia ◽  
Thomas M. Seigler
Keyword(s):  
Robust Control ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Real Time ◽  
Position Control ◽  
Control Performance ◽  
Control Laws ◽  
Shape Memory Alloy Actuator ◽  
Control Scheme ◽  
And Control

Shape memory alloy actuators are inherently nonlinear and require a robust control scheme to guarantee rapid tracking and sufficient position control performance. In this paper, a control scheme is developed for an automotive shape memory alloy actuator that is used to orient an external rear view mirror to match desired set-points. The formulation of appropriate models and control laws are presented. Experiments of the controller in a real-time environment are performed and results are presented.

scholarly journals Velocity Sensor for Real-Time Backstepping Control of a Multirotor Considering Actuator Dynamics

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4229
Author(s):  
Walter Alejandro Mayorga-Macías ◽  
Luis Enrique González-Jiménez ◽  
Marco Antonio Meza-Aguilar ◽  
Luis Fernando Luque-Vega
Keyword(s):  
Real Time ◽  
Test Bench ◽  
Transfer Functions ◽  
Sliding Mode ◽  
Control Law ◽  
Signal Conditioning ◽  
Actuator Dynamics ◽  
Control Scheme ◽  
Angular Velocities ◽  
Actuator Control

A real-time implementation of a control scheme for a multirotor, based on angular velocity sensors for the actuators, is presented. The control scheme is composed of two loops: an inner loop for the actuators and an outer loop for the unmanned aerial vehicle (UAV). The UAV control algorithm is designed by means of the backstepping technique and a robust sliding mode differentiator, and the actuator control strategy is based on a standard proportional-integral-derivative (PID) controller. A robust exact differentiator, based on high order sliding modes, is used to estimate the complex derivatives present in the proposed control law. As the measurements of the propeller’s angular velocities are required for the control law, velocity sensors are mounted in the axles of the rotors to retrieve them and a signal conditioning stage is implemented. In addition, dynamical models for the actuators of the aircraft were calculated by means of transfer functions obtained via experimental measurements in a test bench developed for this purpose. This test bench permits to characterize the parameters of the transfer functions by comparing the forces computed using the nominal parameter to the measured forces. To this end, it is assumed that the loads in the actuators of the vehicle are insignificant during flight. The effectiveness of the proposed sensor, its signal conditioning, and the overall control scheme are validated by means of simulation results and real-time experiments.

UNDERACTUATED HAND DYNAMIC MODELING, ITS REAL-TIME SIMULATION, AND CONTROL

2010 ◽  
Vol 07 (04) ◽  
pp. 609-634 ◽  
Author(s):  
HAI HUANG ◽  
YONG-JIE PANG ◽  
JIANG LI ◽  
SHAO-WEI FAN ◽  
XIN-QING WANG ◽  
...  
Keyword(s):  
Real Time ◽  
Dynamic Model ◽  
Dynamic Models ◽  
Impedance Control ◽  
Differential Algebraic Equations ◽  
Algebraic Equations ◽  
Inverse Dynamic ◽  
Time Dynamic ◽  
Simulation And Control ◽  
And Control

The forward and inverse dynamic models of the underactuated 2-DOF finger have been established in this article based on virtual spring approach. This approach not only avoids the solution of differential-algebraic equations but also leads to a completely decoupled dynamic model that is ideal for directly inverse dynamic analysis, real-time dynamic simulation and control. To verify this approach, an underactuated 3-joint finger has been brought forward. Simulation results from Matlab/Simulink are consistent with those obtained from ADAMS grasp simulations. For the hand real-time dynamic control, the velocity observer has been established based on the dynamic model, the adaptive curve fitting with the observer has obtained precise velocity signals, made up the uncertain parameters such as torsion spring, inertial, damps, etc. and achieved ideal results. By applying dynamics model and observer, the force-based impedance control can realize more accurate and stable force control during grasp.

A novel approach to the real-time modelling of large urban drainage systems

1997 ◽  
Vol 36 (8-9) ◽  
pp. 19-24 ◽  
Author(s):  
Richard Norreys ◽  
Ian Cluckie
Keyword(s):  
Real Time ◽  
Dynamic Models ◽  
Drainage System ◽  
Radar Data ◽  
Urban Drainage ◽  
Real Time Control ◽  
Empirical Modelling ◽  
Time Control ◽  
Novel Approach ◽  
Non Linear Systems

Conventional UDS models are mechanistic which though appropriate for design purposes are less well suited to real-time control because they are slow running, difficult to calibrate, difficult to re-calibrate in real time and have trouble handling noisy data. At Salford University a novel hybrid of dynamic and empirical modelling has been developed, to combine the speed of the empirical model with the ability to simulate complex and non-linear systems of the mechanistic/dynamic models. This paper details the ‘knowledge acquisition module’ software and how it has been applied to construct a model of a large urban drainage system. The paper goes on to detail how the model has been linked with real-time radar data inputs from the MARS c-band radar.

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