The implementation and experimental research on an S-curve acceleration and deceleration control algorithm with the characteristics of end-point and target speed modification on the fly

2016 ◽  
Vol 91 (1-4) ◽  
pp. 1145-1169 ◽  
Author(s):  
Di Li ◽  
Jiewen Wu ◽  
Jiafu Wan ◽  
Shiyong Wang ◽  
Song Li ◽  
...  
Keyword(s):  
Experimental Research ◽  
Control Algorithm ◽  
Target Speed ◽  
End Point ◽  
Acceleration And Deceleration ◽  
S Curve

A Generic Method to Generate AS-Curve Profile in Commercial Motion Controller

2017 ◽  
Author(s):  
Youdun Bai ◽  
Xin Chen ◽  
Zhijun Yang
Keyword(s):  
Motion Controller ◽  
Residual Vibration ◽  
Practical Applications ◽  
Analytic Polynomial ◽  
Acceleration And Deceleration ◽  
Special Knowledge ◽  
Curve Profile ◽  
S Curve ◽  
Motion Profile ◽  
Better Than

It is well believed that S-curve motion profiles are able to reduce residual vibration, and are widely applied in the motion control fields. Recently, a new asymmetric S-curve (AS-curve) motion profile, which is able to effectively adjust the acceleration and deceleration periods, is proposed to enhance the performance of S-curve motion profile, and proved to be better than the traditional symmetric S-curve in many cases. However, most commercial motion controllers do not support the AS-curve motion profiles inherently. Special knowledge or expensive advanced controlling systems, such as dSPACE system, are required to generate the AS-curve motion command, which limits the applications of the AS-curve motion profile in many practical applications. In this paper, a generic method based on the Position-Velocity-Time (PVT) mode move supported by most commercial motion controllers is proposed to generate exact AS-curve motion command in real machines. The analytic polynomial functions of AS-curve motion profile are also derived to simplify the further application, and the effectiveness of the proposed method is verified by numerical simulation.

Research on Digital Control of Meter-In and Meter-Out Independent Regulating for High Inertia Load

1999 ◽  
Author(s):  
Qingfeng Wang ◽  
Linyi Gu ◽  
Yongxiang Lu
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Dynamic Process ◽  
Control Algorithm ◽  
Damping Ratio ◽  
State Feedback Control ◽  
Hydraulic Systems ◽  
Outlet Pressure ◽  
Acceleration And Deceleration ◽  
Valve Control

Abstract The smoothness of acceleration and deceleration process is a serious problem in valve control system with high inertia load, especially in the hydraulic systems in construction machines. In this paper, a meter-in and meter-out independent regulating method, in which the two sides of actuator are controlled by a meter-in valve and a meter-out valve respectively, is put forward, in one hand, the meter-out valve could control the actuator’s outlet pressure to avoid the ultra-high outlet pressure when actuator decelerates or brakes suddenly. On the other hand, the dynamic damping ratio of valve control system could be raised through calculated flow feedback control algorithm. Secondly, a grading control algorithm in dynamic process of high inertia load is adopted. When the actuator’s velocity is far from its command value, the actuator’s inlet and outlet pressure are controlled. After the velocity error decrease to a threshold, a state feedback control algorithm based on parameters on line estimating is employed to realize both its velocity accuracy and the smoothness of dynamic process. Experiments show that the actuator’s velocity could increase or decrease to its command value accurately, smoothly and rapidly after the above method and algorithm are applied.

scholarly journals Research on Multi-Objective Optimization and Control Algorithms for Automatic Train Operation

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3842 ◽  
Author(s):  
Kai-wei Liu ◽  
Xing-Cheng Wang ◽  
Zhi-hui Qu
Keyword(s):  
Predictive Control ◽  
Control Algorithm ◽  
Lower Layer ◽  
Target Speed ◽  
Speed Controller ◽  
Urban Rail ◽  
Train Operation ◽  
Automatic Train Operation ◽  
And Control ◽  
Layer Control

The automatic train operation (ATO) system of urban rail trains includes a two-layer control structure: upper-layer control and lower-layer control. The upper-layer control is to optimize the target speed curve of ATO, and the lower-layer control is the tracking by the urban rail train of the optimal target speed curve generated by the upper-layer control according to the tracking control strategy of ATO. For upper-layer control, the multi-objective model of urban rail train operation is firstly built with energy consumption, comfort, stopping accuracy, and punctuality as optimization indexes, and the entropy weight method is adopted to solve the weight coefficient of each index. Then, genetic algorithm (GA) is used to optimize the model to obtain an optimal target speed curve. In addition, an improved genetic algorithm (IGA) based on directional mutation and gene modification is proposed to improve the convergence speed and optimization effect of the algorithm. The stopping and speed constraints are added into the fitness function in the form of penalty function. For the lower-layer control, the predictive speed controller is designed according to the predictive control principle to track the target speed curve accurately. Since the inflection point area of the target speed curve is difficult to track, the softness factor in the predictive model needs to be adjusted online to improve the control accuracy of the speed. For this paper, we mainly improve the optimization and control algorithms in the upper and lower level controls of ATO. The results show that the speed controller based on predictive control algorithm has better control effect than that based on the PID control algorithm, which can meet the requirements of various performance indexes. Thus, the feasibility of predictive control algorithm in an ATO system is also verified.

Impedance Control: An Approach to Manipulation: Part II—Implementation

1985 ◽  
Vol 107 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Neville Hogan
Keyword(s):  
Feedback Control ◽  
Inverse Kinematics ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Impedance Control ◽  
Dynamic Interaction ◽  
End Point ◽  
Inverse Kinematics Problem ◽  
Theoretical Reasoning ◽  
Redundant Actuators

This three-part paper presents an approach to the control of dynamic interaction between a manipulator and its environment. Part I presented the theoretical reasoning behind impedance control. In Part II the implementation of impedance control is considered. A feedback control algorithm for imposing a desired cartesian impedance on the end-point of a nonlinear manipulator is presented. This algorithm completely eliminates the need to solve the “inverse kinematics problem” in robot motion control. The modulation of end-point impedance without using feedback control is also considered, and it is shown that apparently “redundant” actuators and degrees of freedom such as exist in the primate musculoskeletal system may be used to modulate end-point impedance and may play an essential functional role in the control of dynamic interaction.

scholarly journals Experimental research of incipient turbulent flow frequency spectra in hydrodynamic unsteadiness

2021 ◽  
Vol 13 (2) ◽  
pp. 91-102
Author(s):  
Viacheslav KRAEV
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Flow Structure ◽  
Experimental Research ◽  
Gas Flow ◽  
Frequency Spectra ◽  
Flow Acceleration ◽  
Aerospace Systems ◽  
Acceleration And Deceleration ◽  
Unsteady Conditions

Hydraulic and heat transfer processes play a very important role in the design and prototyping of aerospace technology. Unsteady conditions are the peculiarity of mostly aerospace systems. Flow acceleration and deceleration may significantly affect the heat transfer and hydrodynamic process in channels of aerospace systems. For unsteady process modeling, a fundamental research of unsteady hydrodynamic turbulent flow structure., Moscow Aviation Institute National Research University (MAI) has been building unsteady turbulent flow structures since 1989. An experimental facility was designed to provide gas flow acceleration and deceleration. Experimental data of a turbulent gas flow structure during flow acceleration and flow deceleration are presented. The frequency spectra of axial and radial velocity pulsations are based on experimental data. The results of experimental turbulent flow research demonstrate the fundamental hydrodynamic unsteadiness influence on the flow structure. The main results of the flow acceleration and deceleration experimental research show that there are tangible differences from the steady flow structure. The analysis of unsteady conditions influence on the turbulent pulsations generation and development mechanisms is presented. The results show the unsteady conditions influence onto turbulent vortexes disintegration tempo. The present paper describes a method of experimental research, methodology of data processing and turbulent accelerated and decelerated flow spectra results.

scholarly journals A New Seven-Segment Profile Algorithm for an Open Source Architecture in a Hybrid Electronic Platform

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 652 ◽  
Author(s):  
José R. García-Martínez ◽  
Juvenal Rodríguez-Reséndiz ◽  
Edson E. Cruz-Miguel
Keyword(s):  
Velocity Profile ◽  
Open Source ◽  
Low Cost ◽  
High Stress ◽  
Rate Of Change ◽  
Open Architecture ◽  
Raspberry Pi ◽  
Field Programmable ◽  
Acceleration And Deceleration ◽  
S Curve

The velocity profiles are used in the design of trajectories in motion control systems. It is necessary to design smoother movements to avoid high stress in the motor. In this paper, the rate of change in acceleration value is used to develop an S-curve velocity profile which presents an acceleration and deceleration stage smoother than the trapezoidal velocity profile reducing the error at the end of the duty-cycle pre-established in one degree of freedom (DoF) application. Furthermore, a new methodology is developed to generate a seven-segment profile that works with negative velocity and displacement constraints applying an open source architecture in a hybrid electronic platform compounded by a system on a chip (SoC) Raspberry Pi 3 and a field programmable gate array (FPGA). The performance of the motion controller is measured through the comparison of the error obtained in real-time application with a trapezoidal velocity profile. As a result, a low-cost platform and an open architecture system are achieved.

Method for Feed-Rate Optimization Based on S Curve Acceleration and Deceleration Control of Piecewise Tool Path

2012 ◽  
Vol 542-543 ◽  
pp. 551-554
Author(s):  
Xiao Bing Chen ◽  
Wen He Liao
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
Complex Surface ◽  
Experimental Result ◽  
Threshold Method ◽  
Lower Efficiency ◽  
Acceleration And Deceleration ◽  
S Curve ◽  
Rate Optimization ◽  
Feed Rate Optimization

Aiming at the problem of lower efficiency of complex surface machining with constant feed-rate, a method for feed-rate optimization based on S curve acceleration and deceleration control of piecewise tool path is researched. With constraints of kinematic characters of machine tool and geometric characters of tool path, tool path segments are obtained by curvature threshold method, and feed-rates are planned in these segments, then feed-rate transition of adjacent segments is processed by the method of S curve acceleration and deceleration control. Experimental result indicates that the proposed method is feasible and effective.

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