Motion Control Design Research Articles

Design ADRC for Cutter Suction Dredger Cutter Motor Variable Frequency Drive System

In order to achieve precise speed control for cutter suction dredger cutter motor, the controller should adapt well to uncertainties, such as geological environment, water flow, mechanical disturbance, etc. It makes the design of cutter motor controller always a hard work. This paper proposes an active disturbance rejection controller (ADRC) approach for cutter suction dredger cutter motor variable frequency drive system. Firstly, the LabVIEW platform was established by virtual instrument technology, which collected operating data of cutter motor in fundamental wave and total harmonic distortion (THD). Then cutter motor motion mathematic model was built and the ADRC design method was introduced. Lastly, the simulation results in the cutter velocity control and disturbance environments were done. The results show that the ADRC controller has strong robustness, and the precise speed control can be implemented.

A real-time model of an automotive air propulsion system

This paper develops a real-time automotive air propulsion system for light-duty vehicles. This system consists of a high-pressure air tank, an electric-controlled throttle valve, and a vane-type air motor. The isentropic-nozzle element and control volume concepts were introduced with their governing equations. The tank and throttle valve were modeled as a second-order control volume and nozzle element, respectively. The air motor consisted of four control volumes (12th-order pneumatic dynamics), first-order mechanical dynamics, and a nozzle element as the exhaust port. A 15th-order nonlinear state equation set was derived by integrating these three subsystems. The controlled throttle angle and sequential switch between intake and exhaust processes for the motor chambers allow the whole system to operate properly. A Matlab/Simulink-based simulator was then used for a real-time simulation. Four throttle angles (30°, 50°, 70°, and 90°) were used to show that the derived model is feasible and physically rational. Key variables such as the mass flow rate, temperature, pressure, energy, and mechanical dynamics were investigated in detail for all subsystems. An experimental platform of a 1kW air motor was constructed for model validation. The average experiment/simulation torque error and air flow rate error were 6.15% and 5.34%, respectively. It proves the high accuracy of the model. Future studies with this real-time model should investigate motor specification design, controller design (by hardware-in-the-loop platform), and integration with a light-duty vehicle simulator.

Robust iterative learning for high precision motion control through [formula omitted] adaptive feedback

The diversity of precision motion control applications and their demanding design specifications pose a large array of control challenges. Hence, precision motion control design relies on a variety of advanced control strategies developed to cope with specific problems present in control theory. A popular feedforward control technique for repetitive systems is iterative learning control (ILC). While ILC can decrease tracking errors up to several orders of magnitude, the achievable performance is limited by dynamic uncertainty. We propose the combination of L1 adaptive control (L1 AC) and linear ILC for precision motion control under parametric uncertainties. We rely on the adaptive loop to compensate for parametric uncertainties, and ensure that the plant uncertainty is sufficiently small so that an aggressive learning controller can be designed on the nominal system. We exploit the closed loop stability condition of L1 AC to design simple, robust ILC update laws that reduce tracking errors to measurement noise for time varying references and uncertainties. We demonstrate in simulation that the combined control scheme maintains a highly predictable, monotonic system behavior; and achieves near perfect tracking within a few trials regardless of the uncertainty present.

Electric Machine Analysis, Control and Verification for Mechatronics Motion Control Applications, Using New MATLAB Built-in Function and Simulink Model

This paper proposes a new, simple and user-friendly MATLAB built-in function, mathematical and Simulink models, to be used to early identify system level problems, to ensure that all design requirements are met, and, generally, to simplify Mechatronics motion control design process including; performance analysis and verification of a given electric DC machine, proper controller selection and verification for desired output speed or angle.

Optimal LQ feedforward tracking with preview: Practical design for rigid body motion control

For reference-tracking motion control, preview-based linear quadratic (LQ) design methods provide an effective means to balance tracking performance with available actuation capacity. This paper considers a control structure for which the optimal feedforward controller is independent of the feedback controller. In this way, explicit implementation formulas for feedforward controllers are derived that can be applied to a range of rigid-body motion systems. Key aspects of the optimal LQ solutions are identified, particularly how the choice of design weightings affect steady-state error for polynomial tracking. A redesign procedure for finite preview-time is proposed that preserves exact polynomial tracking properties and control bandwidth of the optimal solutions. Comparative experimental results are presented for a motor-driven linear motion stage.

Active Perturbation Rejection in Motion Control of Milling Machine Tools

This article deals with the robust control problem of the motion axes of milling machine tools subjected to perturbation forces induced by the metal machining process. A position output feedback control scheme is proposed for robust rejection of unknown cutting and friction perturbation forces and robust tracking tasks of motion trajectories planned for a three-axis milling machine tool. The Coulomb friction, viscous damping and cutting forces are considered as terms of an unknown time-varying disturbance input signal affecting the dynamics of the motion axes of the milling machine. In the motion control design, the perturbation signal is modeled locally by a fourth degree Taylor time-polynomial family. Then, a state observer is designed to estimate the disturbance and velocity signals required for implementation of the proposed motion controllers. Simulation results are included to show the robust performance of the proposed motion control scheme and the fast and effective estimation of the perturbation and velocity signals.

Connecting System Identification and Robust Control for Next-Generation Motion Control of a Wafer Stage

Next-generation precision motion systems are lightweight to meet stringent requirements regarding throughput and accuracy. Such lightweight systems typically exhibit lightly damped flexible dynamics in the controller cross-over region. State-of-the-art modeling and motion control design procedures do not deliver the required model complexity and fidelity to control the flexible dynamical behavior. The aim of this paper is to develop a combined system identification and robust control design procedure for high performance motion control and apply it to a wafer stage. Hereto, new connections between system identification and robust control are employed. The experimental results confirm that the proposed procedure significantly extends existing results and enables next-generation motion control design.

Research on Roll Stabilizing Based on Energy Optimization for Autonomous Surface Vehicle

Considering the case of ASV (autonomous surface vehicle) navigating with low speed near water surface, a new method for design of roll motion controller is proposed in order to restrain wave disturbance effectively and improve roll stabilizing performance. Control system design is based on GPC (general predictive control) theory and working principle of zero-speed fin stabilizer. Coupling horizontal motion model of ASV is decoupled, and an equivalent transfer function of roll motion is obtained and transformed into a discrete difference equation through inverse Laplace transformation and Euler approximation. Finally, predictive model of GPC, namely, the difference equation of roll motion, is given. GPC algorithm of ASV roll motion is derived from performance index based on roll stabilizing performance and energy consumption used for driving fin stabilizer. In allusion to time-variant parameters in roll motion model, recursive least square method is adopted for parameter estimation. Simulation results of ASV roll motion control show better stabilizing performance and minimized energy consumption improved by self-adaptive GPC.

Development of quadruped walking robot TITAN XII and its basic consideration on the control of large obstacle traversing motion

Quadruped walking robots are expected to be utilized for various works on rugged terrain because it has minimum leg number to maintain static stability during walking motion and it can demonstrate high terrain adaptability by utilizing its high degrees of freedom. For these reasons, it has been studied for a long time. However, the study about traversing on rugged terrain by quadruped walking robot has not been done enough yet. In this paper, both basic strategy of motion control and mechanical design of a quadruped walking robots for large obstacle climbing are considered. In order to establish the basis of the control of quadruped walking robots to achieve large obstacle traversing motion with high energy efficiency, we make simulation experiments about body rising motion which essentially requires positive power consumption. We investigate the appropriate foot positions and internal forces which eliminate negative power consumption at the joint, then optimize the motion in consideration of characteristics of the installed actuators. Furthermore, a quadruped walking robot to go over large obstacle named“TITAN XII ”is proposed and its design concept and system integration are discussed. Finally, validity of simulation results and basic performance of TITAN XII are confirmed by experiments.

Design of Motion Controller Based on Touch Screen

Motion controller plays a dominant role in motion control system. With the progress and improvement of motion control technology, the research and application of open, high-performance, low-cost and universal embedded motion controller becomes the necessity of the market. The major objective of the paper is to establish the basic software and hardware platform of a high-performance, low-cost and universal embedded motion controller and study the application. And the paper proposes the idea of developing a low-cost and economic touchscreen motion controller, which provides valuable reference for the relevant research and development in China.

Optimal robust motion controller design using multiobjective genetic algorithm.

This paper describes the use of a multiobjective genetic algorithm for robust motion controller design. Motion controller structure is based on a disturbance observer in an RIC framework. The RIC approach is presented in the form with internal and external feedback loops, in which an internal disturbance rejection controller and an external performance controller must be synthesised. This paper involves novel objectives for robustness and performance assessments for such an approach. Objective functions for the robustness property of RIC are based on simple even polynomials with nonnegativity conditions. Regional pole placement method is presented with the aims of controllers' structures simplification and their additional arbitrary selection. Regional pole placement involves arbitrary selection of central polynomials for both loops, with additional admissible region of the optimized pole location. Polynomial deviation between selected and optimized polynomials is measured with derived performance objective functions. A multiobjective function is composed of different unrelated criteria such as robust stability, controllers' stability, and time-performance indexes of closed loops. The design of controllers and multiobjective optimization procedure involve a set of the objectives, which are optimized simultaneously with a genetic algorithm—differential evolution.

Experimental Study on Antivibration Control of Electrical Power Steering Systems

We focus on the antivibration controller design problem for electrical power steering (EPS) systems. The EPS system has significant advantages over the traditional hydraulic steering system. However, the improper motor controller design would lead to the steering wheel vibration. Therefore, it is necessary to investigate the antivibration control strategy. For the implementation study, we also present the motor driver design and the software design which is used to monitor the sensors and the control signal. Based on the investigation on the regular assistant algorithm, we summarize the difficulties and problems encountered by the regular algorithm. After that, in order to improve the performance of antivibration and the human-like steering feeling, we propose a new assistant strategy for the EPS. The experiment results of the bench test illustrate the effectiveness and flexibility of the proposed control strategy. Compared with the regular controller, the proposed antivibration control reduces the vibration of the steering wheel a lot.

Embedded motion controller design based on RTEX network

Adopting embedded framework and network communication mode,a kind of multi-axis embedded motion controller hardware platform design for Panasonic A5N drive was proposed,which was based on the modular control core(ARM + FPGA) and could adapt to the new real-time network communication named RTEX. It was transplanted inμC/OS-Ⅱ. The processes of controller's functional design,hardware design and software design were explained in detail. Up to now,the motion controller's hardware platform had been completed and verified by communication experiments and position and velocity control experiments based on SCARA robot. The experimental results show that the controller has good communication function and stable performance,and can well accomplish the functions of servo control.

From CAD to Robot: Undergraduate Capstone Design in Engineering Technology

A novel senior project in designing and implementing a wheeled platform-based experimental mobile robot is discussed. This mobile robot design project was used as a platform to learn sensor interfacing, microcontroller programming, motor control, and electronic circuit design and troubleshooting. A specially designed proto board was used so that students could experiment with various types of sensors and supporting electronic circuitry. The modules implemented in this project are, servo motor control, infrared (IR)-based obstacle detection and avoidance, temperature sensing, and IR wireless communication. An 8-bit Peripheral Interface Controller (PIC) microcontroller, operating at 20MHz, was used as a programmable controller to monitor external environment through sensors and make appropriate decisions. PIC microcontroller was programmed using PICBasic PRO, a BASIC like high-level language. The implementation was divided into separate experiments, through which the students progressively completed the mobile robot. This progressive experimentation helped students develop their knowledge of interfacing, microcontroller programming, electronic control, circuit design, and troubleshooting in an incremental manner. The robot design experiments, sensor interfacing, electronic control, supporting circuitry, problems faced and troubleshooting during implementation are discussed in the paper.

SoPC-Based Parallel ACO Algorithm and its Application to Optimal Motion Controller Design for Intelligent Omnidirectional Mobile Robots

This paper presents an embedded system-on-a-programmable-chip (SoPC)-based parallel ant colony optimization (ACO) algorithm and its application to optimal motion controller design for intelligent omnidirectional mobile robots. Both polar-space parallel ACO (PACO) parameter tuner and kinematic motion controller are integrated in one field programmable gate arrays chip to efficiently construct an intelligent omnidirectional mobile robot. The optimal parameters of the motion controllers are obtained by minimizing the performance index using the proposed SoPC-based PACO algorithm. These polar-space optimal parameters are then employed in the PACO-based embedded kinematic motion controller to achieve trajectory tracking and stabilization. Experimental results are conducted to show the effectiveness and merit of the proposed PACO algorithm for embedded controllers of omnidirectional mobile robots. These results indicate that the proposed PACO-based embedded optimal controller outperforms the nonoptimal controllers and the conventional genetic algorithm optimal controllers in polar coordinates.

Performance Analysis, Controller Selection And Verification Of Electric Motor For Mechatronics Motion Control Applications, Using New MATLAB Built-In Function And Simulink Model

This paper proposes a new MATLA B built-in function, mathemat ical and simu lin k models, all to be simu ltaneously simple, user–friendly and to be used to face the two top challenges in developing mechatronic motion control systems, particularly, the early identifying system level problems and ensuring that all design requirements are met, as well as, to simplify and accelerate Mechatronics motion control design process including; performance analysis and verificat ion of a g iven electric DC system, p roper controller selection and verification for desired output speed or angle. The proposed models and function are intended for research purposes, application in educational process, and to be used by the mechatronics students and engineers for selection, design and verification purposes.

A minimally invasive surgery robotic assistant for HALS–SILS techniques

This paper is focused in the design and implementation of a robotic surgical motion controller. The proposed control scheme addresses the issues related to the application of a robot assistant in novel surgical scenario, which combines hand assisted laparoscopic surgery (HALS) with the single incision laparoscopic surgery (SILS) techniques. It is designed for collaborating with the surgeon in a natural way, by performing autonomous movements, in order to assist the surgeon during a surgical maneuver. In this way, it is implemented a hierarchical architecture which includes an upper auto-guide velocity planner connected to a low-level force feedback controller. The first one, based on a behavior approach, computes a collision free trajectory of the surgical instrument tip, held by the robot, for reaching a goal location inside of the abdominal cavity. On the other hand, the force feedback controller uses this trajectory for performing the instrument displacement by taking into account the holonomic movement constraints introduced by the fulcrum point. The aim of this controller is positioning the surgical instrument by minimizing the forces exerted over the abdominal wall due to the fulcrum location uncertainty. The overall system has been integrated in the control architecture of the surgical assistant CISOBOT, designed and developed at the University of Malaga. The whole architecture performance has been tested by means of in vitro trials.

Motion Control of the CyberCarpet Platform

The CyberCarpet is an actuated platform that allows unconstrained locomotion of a walking user for Virtual Reality exploration. The platform consists of a linear treadmill covered by a ball-array carpet and mounted on a turntable, and is equipped with two actuating devices for linear and angular motion. The main control objective is to keep the walker close to the platform center in the most natural way, counteracting his/her voluntary motion while satisfying perceptual constraints. The motion control problem for this platform is not trivial since the system kinematics is subject to a nonholonomic constraint. In the first part of the paper we describe the kinematic control design devised within the CyberWalk project, where the linear and angular platform velocities are used as input commands and feedback is based only on walker's position measurements obtained by an external visual tracking system. In particular, we present a globally stabilizing control scheme that combines a feedback and a feedforward action, based on a disturbance observer of the walker's intentional velocity. We also discuss possible extensions to acceleration-level control and the related assessment of dynamic issues affecting a walker during his/her motion. The second part of the paper is devoted to the actual implementation of the overall system. As a proof of concept of a final full-scale platform, the mechanical design and realization of a small-scale prototype of the CyberCarpet is presented, as well as the visual localization method used to obtain the human walker's position on the platform by an overhead camera. To validate the proposed motion control design, experimental results are reported and discussed for a series of motion tasks performed using a small tracked vehicle representative of a moving user.

Path tracking design based on I/O Davidson-Cole transfer function for square MIMO systems

The aim of this paper concerns motion control and robust path tracking design for square MIMO systems. A path tracking approach using fractional differentiation is proposed, based on direct optimization of an I/O Davidson-Cole type transfer function. The main important property of this transfer function is that it does not present overshoot on its output and allows synthesis with only two parameters to obtain an optimal settling time. The SISO approach was presented in previous works. This paper presents an extension for square multivariable systems. Using MIMO-QFT robust synthesis methodology and taking into account the plant uncertainties, the fractional prefilters are deduced. This method specifically deals with the appropriate transformation of the MIMO system to the equivalent MISO system. The optimization of the two prefilter parameters is founded on the plant output error integral minimization, considering the actuators physical constraints and the tracking performance specifications. A numerical example is considered to indicate performances of the used procedure.

Design of Five Axis Cooperation Machine Based on Motion Control Board

Abstract. PC-based open CNC system can fully take advantage of the computer's hardware and software resources, which can use a common high-level language: Visual C++ or Visual Basic to program. User can mix and use the standardized peripherals, application software flexibly, we use the self-developed five-axis CNC machine is experimental platform, which can develop open CNC system based on PC and motion control card. Using of five-axis machine motion control design based on "PC + motion control card" on Visual C++ platform.