Fault Detection for Lumped-Parameter LTI Systems using Integral Transformations and Trajectory Planning Methods

2021 ◽  
Author(s):  
Ferdinand Fischer ◽  
Velimir Todorovski ◽  
Joachim Deutscher
Keyword(s):  
Fault Detection ◽  
Trajectory Planning ◽  
Integral Transformations ◽  
Lumped Parameter ◽  
Planning Methods

Improved Trajectory Planning using Arbitrary Power Polynomials

1994 ◽  
Vol 208 (1) ◽  
pp. 3-13 ◽  
Author(s):  
A Kirecci ◽  
M J Gilmartin
Keyword(s):  
Trajectory Planning ◽  
Interpolation Method ◽  
Attractive Alternative ◽  
Mathematical Functions ◽  
General Application ◽  
Arbitrary Power ◽  
Recent Developments ◽  
Planning Methods ◽  
Machine Systems ◽  
Conventional Systems

Increasing demands for higher operational speeds, the need for flexible machinery and recent developments in microchip technology have made programmable machine systems an attractive alternative to conventional systems. However, some difficulties still remain for proper control of programmable systems, especially at higher speeds. These can be categorized into two groups: trajectory planning and trajectory tracking. Conventional trajectory planning methods are ineffective for general application, especially when velocity and acceleration conditions are included. There are many mathematical functions but polynomials are shown to be the most versatile for trajectory planning; however, these can give curves with unexpected oscillations, commonly called meandering. Tracking of a motion in this situation could engender severe practical problems. In this study, a new interpolation method using polynomials with arbitrary powers is proposed to overcome this disadvantage.

scholarly journals A Multi-Sensor Based Roadheader Positioning Model and Arbitrary Tunnel Cross Section Automatic Cutting

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4955
Author(s):  
Changqing Yan ◽  
Wenxiao Zhao ◽  
Xinming Lu
Keyword(s):  
Real Time ◽  
Cross Section ◽  
Trajectory Planning ◽  
Hydraulic Cylinder ◽  
High Accuracy ◽  
Position Measurement ◽  
Coordinate Measurement ◽  
Positioning Method ◽  
Planning Methods ◽  
Tunnel Cross Section

Autonomous posture detection and self-localization of roadheaders is the key to automatic tunneling and roadheader robotization. In this paper, a multi-sensor based positioning method, involving an inertial system for altitude angles measurement, total station for coordinate measurement, and sensors for measuring the real-time length of the hydraulic cylinder is presented for roadheader position measurement and posture detection. Based on this method, a positioning model for roadheader and cutter positioning is developed. Additionally, flexible trajectory planning methods are provided for automatic cutting. Based on the positioning model and the trajectory planning methods, an automatic cutting procedure is proposed and applied in practical tunneling. The experimental results verify the high accuracy and efficiency of both the positioning method and the model. Furthermore, it is indicated that arbitrary shapes can be generated automatically and precisely according to the planned trajectory, employing the automatic cutting procedure. Therefore, unmanned tunneling can be realized by employing the proposed automatic cutting process.

scholarly journals Numerical Aspects and Performances of Trajectory Planning Methods of Flexible Axes

2006 ◽  
Vol 1 (4) ◽  
pp. 35 ◽  
Author(s):  
Jean-Yves Dieulot ◽  
Issam Thimoumi ◽  
Frédéric Colas ◽  
Richard Béarée
Keyword(s):  
Optimal Control ◽  
Path Planning ◽  
Natural Frequency ◽  
Trajectory Planning ◽  
Input Shaping ◽  
Robot Arm ◽  
Frequency Mismatch ◽  
Planning Methods ◽  
Real Robot ◽  
Theoretical Results

Adequate Path Planning design is an important stage for controlling flexible axes because it may allow to cancel vibrations induced by oscillating modes. Among bang-bang profiles which are linked to optimal control, jerk assignment (acceleration derivative) and input shapers have been investigated. Theoretical results show the performance and robustness with respect to natural frequency mismatch. Practical validations on a real robot arm show the relevance of the jerk algorithm which is more robust with the same productivity performances as input shaping techniques.

Online collision avoidance trajectory planning for spacecraft proximity operations with uncertain obstacle

2021 ◽  
pp. 095441002110561
Author(s):  
Run-de Zhang ◽  
Wei-wei Cai ◽  
Le-ping Yang ◽  
Cheng Si
Keyword(s):  
Collision Avoidance ◽  
Predictive Control ◽  
Trajectory Planning ◽  
Three Dimensional ◽  
Performance Criteria ◽  
Proximity Operations ◽  
Online Planning ◽  
Planning Framework ◽  
Planning Methods ◽  
Avoidance Problem

The spacecraft relative motion trajectory planning is one of the enabling techniques for autonomous proximity operations, especially in the increasingly complicated mission environments. Most traditional trajectory planning methods focus on improving the performance criteria in the deterministic conditions, whereas various uncertain elements in practice would significantly degrade the trajectory performance. Considering the uncertainties underlying the collision avoidance constraints, this paper suggests a model predictive control based online trajectory planning framework in which the obstacle information in higher-precision would be consistently updated by the onboard sensor. To improve the computational efficiency of the online planning framework, the rotating hyperplane (RH) technique is utilized to transform the nonlinear ellipsoidal keep-out zone constraints into convex formulations. And the concept of rotation window is introduced to eliminate the unexpected mismatch between the spacecraft motion and hyperplane rotation in the conventional RH method, which in sequence improves the RH method’s capability for multiple obstacle avoidance problem. Moreover, a three-dimensional (3-D) extension strategy is proposed to simplify the computation procedure when applying the RH method for a 3-D collision avoidance problem. Numerical simulations are carried out to validate the performance of the proposed online trajectory planning framework in addressing the uncertain collision avoidance constraints.

scholarly journals Simulation and Experimental Validation of Novel Trajectory Planning Strategy to Reduce Vibrations and Improve Productivity of Robotic Manipulator

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 581
Author(s):  
Andrea Ariano ◽  
Valerio Perna ◽  
Adolfo Senatore ◽  
Roberto Scatigno ◽  
Fabio Nicolò ◽  
...  
Keyword(s):  
Natural Frequency ◽  
Trajectory Planning ◽  
Planning Process ◽  
Closed Form Solution ◽  
Experimental Tests ◽  
Form Solution ◽  
Residual Vibration ◽  
Dynamic Simulations ◽  
Planning Strategy ◽  
Lumped Parameter

This paper aims at investigating vibrational behaviors of the industrial manipulator Racer 7-1.4, designed and manufactured by COMAU S.p.A., with the target of new trajectory planning strategies to improve productivity rate without any loss of positioning accuracy. Starting from the analysis of a 9DoF multi-body system with lumped parameter, the first natural frequency of the robot was calculated in seven reference positions. Then, static and dynamic simulations were run by applying saturated ramp input and large motions to analyze the vibrational behavior of the manipulator. This research underlines that the optimal way to design the robot move is to set its duration at twice a period of free oscillation according to the first vibrational mode. Due to strong analogy of dynamic response of both 1DoF and 9DoF robot models, the closed-form solution of the 1DoF undamped system—featured by natural frequency equal to the first frequency of the 9DoF system—may be successfully adopted by the real-time trajectory planning process to predict residual vibration at move end-condition. This strategy was confirmed by experimental tests, allowing either residual vibration decrease and execution time reduction as well.

scholarly journals Kinematic Analysis and Motion Planning of Cable-Driven Rehabilitation Robots

2021 ◽  
Vol 11 (21) ◽  
pp. 10441
Author(s):  
Jingyu Zhang ◽  
Dianguo Cao ◽  
Yuqiang Wu
Keyword(s):  
Trajectory Planning ◽  
Kinematic Model ◽  
Length Change ◽  
Planning Method ◽  
Lower Limbs ◽  
Kinematic Equation ◽  
Vector Method ◽  
Cable Length ◽  
Dynamics And Control ◽  
Planning Methods

In this study, a new cable-driven rehabilitation robot is designed, the overall design of the robot is given, and the kinematic equation of the lower limbs in the supine state of the human body is addressed. Considering that cable winders move along the rail brackets, the closed vector method is applied to establish the kinematic model of the robot, and the relationship between the human joint angle and the cable length change was deduced. Considering joint compliance, a fifth-order polynomial trajectory planning method based on an S-shaped curve is proposed by introducing an S-shaped velocity curve, and the changes in cable length displacement, velocity, and acceleration are simulated and analyzed. Three planning methods are compared based on two indices, and experimental verification is carried out on the rehabilitation experiment platform. The simulation and experimental results show that the trajectory planning method presents low energy consumption and strong flexibility, and can achieve better rehabilitation effect, which builds a good basis for the subsequent study of dynamics and control strategy.

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