Deceleration Algorithm Research Articles

Application of Improved S-Curve Flexible Acceleration and Deceleration Algorithm in Smart Live Working Robot

Smart live working robot incorporates the merits of security and reliability, which can greatly improve automation rate of living working, suitable for power distribution network live working applications. Due to flexible strike and shake in automatic stripping wire module of smart live working robot start and end period, an improved S-curve flexible acceleration and deceleration control method is proposed. Based on analyzing disadvantage of conventional linear and exponential acceleration and deceleration algorithm, formula math model of improved cubic polynomial S-curve acceleration and deceleration algorithm is derived. Five-paragraph format motion planning is adopted the proposed S-curve control method, which can realize appointed acceleration and deceleration time moving. Meanwhile, the acceleration is continuous during moving period, and according to different working condition, different Scurve type can be chose. The simulation and practical operating results showed that proposed control strategy can effectively reduce flexible strike, thus improving stationarity and accuracy of the control system.

Fast and high-precision electric adjusting mirror

The mirror in the high-energy laser beam combining system needs to make a fast and high-precision pointing adjustment before working. A two-dimensional electrically controlled adjusting mirror was designed. The main body of the system adopted an integrated flexible support design, the drive adopted a stepping motor and a deceleration mechanism to drive the screw, the precision measurement of the mirror deflection angle adopted an eddy current sensor, and the digital signal processor (DSP) was adopted as the main control module. The working principle and design of the system were analyzed, and the system calibration method as well as the control algorithm were deeply studied. In order to meet the requirements of system adjustment speed, the S-shaped acceleration and deceleration algorithm was adopted as the control algorithm of adjusting mirror, and the system calibration method with piecewise linearity was adopted. Finally, the system was tested experimentally. The experimental results show that within the angle range of ±500″, the in-position time of adjusting mirror is within 3 s, and the control error is less than 2″, which can meet the system requirements.

Design and Function Realization of Nuclear Power Inspection Robot System

SUMMARYThe particularity of nuclear power plant environment requires that the nuclear power inspection robot must be remote control operation. The main purpose of the inspection robot is to carry out inspection, prevention, reporting, and safety emergency operation on the instruments, so as to provide guarantee for the safe operation of the nuclear power plant. Based on the representative configuration of nuclear power robot at home and abroad, this paper develops a small and lightweight nuclear power plant inspection robot, including walking mechanism, lifting mechanism, operating mechanism, image acquisition, information communication and control system, etc., to carry on the statics analysis to the key components of the inspection robot and verify that the stiffness and strength of the mechanical structure meet the requirements of lightweight design. Modal analysis is carried out to verify that the motor does not cause resonance when working. The kinematic model of the robot has been established and can provide the theoretical basis for the controller design. A hierarchical control system based on LabVIEW upper computer monitoring and control operation interface is established, which uses adaptive fuzzy Proportional Integral Derivative (PID) control to simulate the walking control, and then realizes the control of walking mechanism through software programming, and the adaptive fuzzy PID control has better effect than the conventional PID control. The S-type acceleration and deceleration algorithm is used to realize the accurate control of the position location of the lifting mechanism. Finally, combined with the experiment of 5MS robot comprehensive experimental platform, it is proved that the inspection robot can realize remote control function operation.

A corner smoothing method with feedrate blending for linear segments under geometric and kinematic constraints

To eliminate the disadvantages of linear interpolation and geometry-based smoothing methods, the one-step corner smoothing method with feedrate blending algorithm for linear segments is proposed in this article. In the proposed method, the variable acceleration and jerk optimization method will be first adopted to determine the dynamic performance of each linear segment for feedrate scheduling, which takes the different axial limits into consideration. Then, the feedrate scheduling method based on the S-type acceleration and deceleration algorithm is implemented to generate smooth feedrate profiles. Moreover, the feedrate blending algorithm is adopted to calculate the corner time analytically within the specified corner error and thus to generate the smooth trajectory without inserting a smooth curve at adjacent linear segments. With the presented one-step corner smoothing method, a smoother and more accurate trajectory could be generated with faster machining time. The results of simulations and machining experiments demonstrate the effectiveness of the proposed method.

Simultaneous path planning and trajectory optimization for high-speed sorting system

This article presents a strategy for efficient sorting path planning and trajectory optimization with multiple constraints. The proposed strategy is applicable to typical high-density sorting applications. It plans the sorting path while optimizing each trajectory. The total stroke traveled by the end effector to complete the sorting task is shortened, and the efficiency of the production line is correspondingly facilitated. Thus, this article designs bow-shaped trajectories by analyzing the work process of the production line to ensure the smooth transition of the end effector and bow-shaped trajectories are based on the starting point and the end point of each sorting action. The modified trapezoidal acceleration and deceleration algorithm is used to optimize each sorting trajectory, which ensures that each sorting action is executed quickly and stably. Simultaneously, the greedy strategy is applied to plan the sorting task, which further shortens the total stroke of the end effector and improves the efficiency of the production line. A specific cost function is also designed to improve the planning strategy to prevent the occurrence of missing materials and enhance the adaptability of the sorting system. In consideration of the efficiency of the sorting system is significantly improved by this approach, the effectiveness of the proposed strategy in this article is thus verified compared with existing ones by experiments. In addition, the impact of the conveyor speed on the sorting system is also discussed.

Velocity control algorithm in glass polishing based on the cubic NURBS curve

To limit velocity fluctuations and to achieve a controllable jerk value in a glass polishing process, a new velocity control algorithm is proposed based on nonuniform rational B-splines (NURBS). The key of this algorithm is replacing the traditional linear acceleration–deceleration with flexible NURBS acceleration–deceleration. Based on the linear acceleration–deceleration algorithm, the control points of the NURBS curve are confirmed, and the final velocity of the polishing wheel center is solved using the Preston equation. With jerk continuity and limitations of the servo system, nonlinear equations are constructed, and the weighting factors corresponding to the control points are obtained. Cubic velocity control equations can be derived from the obtained feature parameters, which include the final velocity, control points, weighting factors and knot vectors. Based on the proposed NURBS acceleration–deceleration algorithm, a fourth-order Runge–Kutta formula was used to obtain the initial points, and the Milne–Hamming equation was used to predict and correct the next point. The predictor-corrector interpolation algorithm for parametric trajectory was implemented during the polishing process. The experimental results indicate that the proposed approach guarantees limited fluctuations of the relative velocity at contact points and ensure smoother velocity changes at dangerous points.

Motion performance analysis and control mode design for the cross slide

The motion control system which is constructed by using the programmable controller and the motion controller has been widely applied to various mechanical systems. This paper takes a cross slide as an example, the motion control system is composed of the GE FANUC PAC and DSM324i, and the movement performance simulation model is established. The motion performance by linear acceleration and deceleration algorithm in the case of two axis synchronous movement is analyzed. The relation between the displacement command and the parameters of the acceleration and the velocity is derivated, and the trajectory curve of movement performance under a variety of instruction is gained. The control instruction meet the linear motion is designed by the model.

Structural Modelling and Deceleration Algorithm for a Follow Aircraft on Performance-Based Navigation Airway Based on Multi-Agent Technique

Abstract Considering the operation characteristics of the high-speed PBN airway, we propose an aircraft agent structural model and a basic algorithm flow of decision-making by Multi-agent technique. According to the constraint of safe separation and speed with the aircrafts, making use of the car-following theory, the deceleration constraint model is built for a flight management system. When the front aircraft decelerates, the model can offer a speed adjustment proposal for the following aircraft. The model is built based on the minimal safe separation and speed interval constraint; each variable, influencing the deceleration of the following aircraft can be analyzed. Simulation analysis is carried out for different combinations of aircraft types, initial speed, safe separation and deceleration. The follow aircraft deceleration was calculated under different conditions and the results coincided with reality. It is proved that the model can provide safe separation between the two aircrafts.

Research on Design of Industrial Robot

the existing experimental industrial robot systems are introduced in detail in this paper, including hardware description connection parameter settings and circuits, as well as the entire experimental system to complete the task. We also study the acceleration and deceleration algorithm handling robot using the servo robot more stable during operation, positioning more accurate, improve the mechanical hand function during operation, providing convenient cost-effective control system for the entire robot control system.

Velocity Planning for Large Inertia Servo System Based on Power and Torque Constraints

To improve response rate and positioning accuracy of large inertia servo system, the velocity is planned based on power and torque constraints. Globally flexible acceleration and deceleration(ad) algorithm based on trigonometric function is proposed, and a derivable and continuous velocity planning function is designed to reduce high-frequency component. Quadratic curve is employed to connect acceleration curve in incomplete process. Velocity planning algorithm is designed based on both nominal power and maximum torque constrains utilizing overload characteristic and maximum torque of the servo motor, and the condition of constrains is smoothly changed at the maximum torque point as well. The relation formula of constant speed and ad time is given by utilizing displacement as command signal to satisfy different requirements. Single pulse interval is calculated based on mean velocity, and a left-end curve implementation method with interval threshold is designed to reduce computation cost for computer program. This method can be also used in other pulse-given servo systems. Testing and application results demonstrates the effectiveness and reliability of the proposed methods. The presented method improves target positioning accuracy and is successfully applied in test system.

Comparison of Model-Scale and Full-scale Deceleration of a Fully Skirted Air Cushion Vehicle in Sideslip

This article provides experimental results and shows comparisons of 90° sideslip performance of a fully skirted air cushion vehicle using theoretical predictions, 1/12th model-scale data, and full-scale data. The goal is to establish a relation among the three data sets and draw conclusions for use in future predictions. First, this article presents results and analysis of tow tank data obtained in late 2008. Then, the Froude scaled data are used to obtain an empirical drag coefficient. A comparison is made between this approach and a theoretical prediction proposed in previous work. An iterative, one-dimensional deceleration algorithm is then constructed using the coefficients to predict the deceleration of a full-scale craft having similar skirt characteristics. The predictions are performed for three craft weights and the resulting deceleration rates as a function of Froude number are presented. Data obtained from full-scale testing are then compared with the results of both the model-based algorithm and the theoretical prediction. In general, the model-based simulation overpredicts the deceleration rate for a full-scale craft, whereas the theoretical prediction is more accurate. The model simulation is recomputed using a developed correction factor and is plotted against the theoretical and full-scale deceleration, revealing favorable results. Lastly, a review of the technique is described and recommendations for improvements and following work are provided.

Comparison of Model-Scale and Full-scale Deceleration of a Fully Skirted Air Cushion Vehicle in Sideslip

This article provides experimental results and shows comparisons of 90 sideslip performance of a fully skirted air cushion vehicle using theoretical predictions, 1/12th model scale data, and full-scale data. The goal is to establish a relation among the three data sets and draw conclusions for use in future predictions. First, this article presents results and analysis of tow tank data obtained in late 2008. Then, the Froude scaled data are used to obtain an empirical drag coefficient. A comparison is made between this approach and a theoretical prediction proposed in previous work. An iterative, one dimensional deceleration algorithm is then constructed using the coefficients to predict the deceleration of a full-scale craft having similar skirt characteristics. The predictions are performed for three craft weights and the resulting deceleration rates as a function of Froude number are presented. Data obtained from full-scale testing are then compared with the results of both the model-based algorithm and the theoretical prediction. In general, the model-based simulation overpredicts the deceleration rate for a full-scale craft, whereas the theoretical prediction is more accurate. The model simulation is recomputed using a developed correction factor and is plotted against the theoretical and full-scale deceleration, revealing favorable results. Lastly, a review of the technique is described and recommendations for improvements and following work are provided.

Acceleration and deceleration control of assembly machine for assembled camshafts

Aimed at the production requirements of the assembly machine for assembled camshafts, the current paper proposes a revised S-type curve acceleration and deceleration algorithm to improve the existing inner algorithm of the numerical control system. The axial dimension of the camshaft and the phase angle of the cam before and after implementing the new algorithm were checked. The results show that for each type of camshaft, the error of the axial dimension of the camshaft is less than ±0.2 mm and the error of the phase angle of the cam is less than ±30′. In addition and most importantly, the production efficiency is greatly improved (assembly time 90–120 s per piece). This indicates that the proposed algorithm not only assures the stability and precision of the assembly machine for assembled camshafts, but also significantly reduces the assembly time.

Research on a New Flexible Acceleration and Deceleration Algorithm with Continuous Jerk

Control of the motion process of acceleration/deceleration (Acc/Dec) is one of key complicated problems in CNC system development. The excellent Acc/Dec control can improve the processing precision. The traditional Acc/Dec algorithms such as the linear and the exponential are not suitable for high speed motion because there would be flexible impacts existing in feed motion, especially that the jerk of the S-shape curve Acc/Dec is discontinuous. A new flexible Acc/Dec algorithm for high speed motion system based on the squared sine function is introduced. The modeling of the Acc/Dec algorithm with Trigonometric Function Squared Sine(TFSS) shape curve is constructed.In this algorithm, the sine curve in jerk, acceleration, velocity and displacement are all continuous. The simulation experiments result demonstrate that the Acc/Dec algorithm with TFSS shape curve is a new method of continuous Jerk for the design flexible Acc/Dec.

A High-Speed Positioning Method for Servo Systems

The positioning accuracy and positioning time of CNC systems have recently been the main performance criteria for industrial applications. The acceleration/deceleration modes, especially the deceleration modes, have an important effect on them. In this paper, firstly, some problems of the conventional linear deceleration algorithm are analyzed. Then an improved linear acceleration/deceleration algorithm is introduced. In this algorithm, the deceleration point is predicted exactly, and then the deceleration point error is compensated for at higher feedrates. Furthermore, a higher resultant maximum acceleration than that in the conventional scheme is selected to shorten the acceleration/deceleration time. Compared with the conventional linear acceleration and deceleration algorithm, the system performance has been significantly improved. Finally, the performance is confirmed by several simulations and experiments.

A rapid and accurate positioning method with linear deceleration in servo system

The positioning accuracy and positioning time of CNC system have recently been the main performance criteria for industrial applications. The acceleration/deceleration modes, especially deceleration mode, have an important effect on them. The linear deceleration mode is a commonly used deceleration mode. In conventional linear deceleration mode, there is a positioning stage at low speed for a long time after decelerating to ensure the positioning accuracy, because of the “dead zone” and the deceleration point error. In this paper, firstly, some problems in the conventional linear deceleration algorithm are analyzed. Then an improved linear acceleration/deceleration is introduced. In this algorithm, the deceleration point is predicted exactly, and then the deceleration point error is compensated for at higher feedrates. Furthermore, a higher resultant maximum acceleration than that in the conventional scheme is selected to shorten the acceleration/deceleration time. Thus, the positioning stage in conventional scheme is almost cancelled. Compared with that of conventional linear acceleration and deceleration algorithm, the system performance has been significantly improved. Finally, it is confirmed by many simulations and experiments.