A New Real-Time Iteration Method Based on Geometry for Inverse Kinematics of Truck Mounted Concrete Pump

2013 ◽  
Vol 373-375 ◽  
pp. 2109-2113
Author(s):  
Long An Chen ◽  
Ying Jie Shen ◽  
Zhi Nan Mi
Keyword(s):  
Real Time ◽  
Iteration Method ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Variable Step Size ◽  
Real Time Control ◽  
Step Size ◽  
Time Control ◽  
Variable Step ◽  
Concrete Pump

A new iteration method based on geometry to solve the inverse kinematics for the boom system of truck mounted concrete pump, which is difficult to real-time control since its degrees of freedom are multiple-redundant, is presented. This method uses a variable-step size technique to approach the solution of the inverse kinematics, and uses geometry to determine how much angles of joint to change and its direction. Comparing with the traditional methods, this method is more suitable for real-time control of truck mounted concrete pump boom system without calculating the inverse matrix of jacobian. By the method the movement of boom will be safer and more stable when pumping concrete. Simulation results show that the new method has a fast convergence speed and good stability.

Real Time, Near-Optimal Trajectory Planning of an Omni-Directional Vehicle

2001 ◽  
Author(s):  
Tamás Kalmár-Nagy ◽  
Pritam Ganguly ◽  
Raffaello D’Andrea
Keyword(s):  
Real Time ◽  
Optimal Trajectory ◽  
Degrees Of Freedom ◽  
Dynamic Environments ◽  
Real Time Control ◽  
Uncertain Environments ◽  
Time Control ◽  
Innovative Method ◽  
Optimal Trajectory Planning ◽  
Three Degrees Of Freedom

Abstract In this paper, we discuss an innovative method of generating near-optimal trajectories for a robot with omni-directional drive capabilities, taking into account the dynamics of the actuators and the system. The relaxation of optimality results in immense computational savings, critical in dynamic environments. In particular, a decoupling strategy for each of the three degrees of freedom of the vehicle is presented, along with a method for coordinating the degrees of freedom. A nearly optimal trajectory for the vehicle can typically be calculated in less than 1000 floating point operations, which makes it attractive for real-time control in dynamic and uncertain environments.

The Algorithm of Redundant Robotic Kinematics Based on Exponential Product

2011 ◽  
Vol 58-60 ◽  
pp. 1902-1907 ◽  
Author(s):  
Xin Fen Ge ◽  
Jing Tao Jin
Keyword(s):  
Real Time ◽  
Inverse Kinematics ◽  
Screw Theory ◽  
Product Formula ◽  
Real Time Control ◽  
Time Control ◽  
Direct Kinematics ◽  
Product Formulas

The intrinsically redundant series manipulator’s kinematics were studied by the exponential product formula of screw theory, the direct kinematics problem and Inverse kinematics problems were analyzed, and the intrinsically redundant series manipulator’s kinematics solution that based on exponential product formulas were proposed; the intrinsically redundant series manipulator’s kinematics is decomposed into several simple sub-problems, then analyzed sub-problem, and set an example to validate the correctness of the proposed method. Finally, comparing the exponential product formula and the D-H parameters, draw that they are essentially the same in solving the manipulator’s kinematics, so as to the algorithm of the manipulator’s kinematics based on exponential product formulas are correct, and the manipulator’s kinematics process based on exponential product formula is more simple and easier to real-time control of industrial.

scholarly journals A Real-Time Implementation of Novel and Stable Variable Step Size MPPT

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4668 ◽  
Author(s):  
Maissa Farhat ◽  
Oscar Barambones ◽  
Lassaâd Sbita
Keyword(s):  
Real Time ◽  
Maximum Power ◽  
Variable Step Size ◽  
System Control ◽  
Resistive Load ◽  
Step Size ◽  
Pv System ◽  
Variable Step ◽  
Improved Performance ◽  
Power Point

This paper presents a complete study of a standalone photovoltaic (PV) system including a maximum power tracker (MPPT) driving a DC boost converter to feed a resistive load. Here, a new MPPT approach using a modification on the original perturb and observe (P&O) algorithm is proposed; the improved algorithm is founded on a variable step size (VSZ). This novel algorithm is realized and efficiently implemented in the PV system. The proposed VSZ algorithm is compared both in simulation and in real time to the P&O algorithm. The stability analysis for the VSZ algorithm is performed using Lyapunov’s stability theory. In this paper, a detailed study and explanation of the modified P&O MPPT controller is presented to ensure high PV system performance. The proposed algorithm is practically implemented using a DSP1104 for real-time testing. Significant results are achieved, proving the validity of the proposed PV system control scheme. The obtained results show that the proposed VSZ succeeds at harvesting the maximum power point (MPP), as the amount of harvested power using VSZ is three times greater than the power extracted without the tracking algorithm. The VSZ reveals improved performance compared to the conventional P&O algorithm in term of dynamic response, signal quality and stability.

scholarly journals A novel energy-motion model for continuous sEMG decoding: from muscle energy to motor pattern

2020 ◽  
Author(s):  
Gang Liu ◽  
Lu Wang ◽  
Jing Wang
Keyword(s):  
Real Time ◽  
Degrees Of Freedom ◽  
Motor Pattern ◽  
Human Hand ◽  
Motion Model ◽  
Real Time Control ◽  
Prosthetic Hands ◽  
Time Control ◽  
Energy Mode ◽  
Muscle Energy

Myoelectric prosthetic hands create the possibility for amputees to control their prosthetics like native hands. However, user acceptance of the extant myoelectric prostheses is low. Unnatural control, lack of sufficient feedback, and insufficient functionality are cited as primary reasons. Recently, although many multiple degrees-of-freedom (DOF) prosthetic hands and tactile-sensitive electronic skins have been developed, no non-invasive myoelectric interfaces can decode both forces and motions for five-fingers independently and simultaneously. This paper proposes a myoelectric interface based on energy allocation and fictitious forces hypothesis by mimicking the natural neuromuscular system. The energy-based interface uses a kind of continuous “energy mode” in the level of the entire hand. According to tasks itself, each energy mode can adaptively and simultaneously implement multiple hand motions and exerting continuous forces for a single finger. Also, a few learned energy modes could extend to the unlearned energy mode, highlighting the extensibility of this interface. We evaluate the proposed system through off-line analysis and operational experiments performed on the expression of the unlearned hand motions, the amount of finger energy, and real-time control. With active exploration, the participant was proficient at exerting just enough energy to five fingers on “fragile” or “heavy” objects independently, proportionally, and simultaneously in real-time. The main contribution of this paper is proposing the bionic energy-motion model of hand: decoding a few muscle-energy modes of the human hand (only ten modes in this paper) map massive tasks of bionic hand.

scholarly journals Myoelectric digit action decoding with multi-label, multi-class classification: an offline analysis

2020 ◽  
Author(s):  
Agamemnon Krasoulis ◽  
Kianoush Nazarpour
Keyword(s):  
Real Time ◽  
Degrees Of Freedom ◽  
Real Time Control ◽  
Artificial Joints ◽  
Time Control ◽  
Offline Analysis ◽  
Prosthesis Control ◽  
Multi Class Classification ◽  
Prosthetic Finger ◽  
Finger Control

ABSTRACTThe ultimate goal of machine learning-based myoelectric control is simultaneous and independent control of multiple degrees of freedom (DOFs), including wrist and digit artificial joints. For prosthetic finger control, regression-based methods are typically used to reconstruct position/velocity trajectories from surface electromyogram (EMG) signals. Although such methods have produced highly-accurate results in offline analyses, their success in real-time prosthesis control settings has been rather limited. In this work, we propose action decoding, a paradigm-shifting approach for independent, multi-digit movement intent decoding based on multi-label, multi-class classification. At each moment in time, our algorithm classifies movement action for each available DOF into one of three categories: open, close, or stall (i.e., no movement). Despite using a classifier as the decoder, arbitrary hand postures are possible with our approach. We analyse a public dataset previously recorded and published by us, comprising measurements from 10 able-bodied and two transradial amputee participants. We demonstrate the feasibility of using our proposed action decoding paradigm to predict movement action for all five digits as well as rotation of the thumb. We perform a systematic offline analysis by investigating the effect of various algorithmic parameters on decoding performance, such as feature selection and choice of classification algorithm and multi-output strategy. The outcomes of the offline analysis presented in this study will be used to inform the real-time implementation of our algorithm. In the future, we will further evaluate its efficacy with real-time control experiments involving upper-limb amputees.

Nonlinear analysis of rotor system supported by oil lubricated bearings subjected to base movements

2015 ◽  
Vol 230 (4) ◽  
pp. 543-558 ◽  
Author(s):  
Rui Wang ◽  
Xinglin Guo ◽  
Yuefang Wang
Keyword(s):  
Centrifugal Pump ◽  
Seismic Wave ◽  
Degrees Of Freedom ◽  
Rotor System ◽  
Response Analysis ◽  
Variable Step Size ◽  
Step Size ◽  
Six Degrees Of Freedom ◽  
Acceleration Data ◽  
Variable Step

Response analysis of rotor system subjected to the base movements in a large rotational machinery is a complex high-dimensional nonlinear problem. In this paper, rotor system of a centrifugal pump with a pair of oil lubricated bearings is modeled as a six-degrees-of-freedom nonlinear system by the Lagrange method. The Runge–Kutta–Felburg method with variable step size is applied to solve the equations based both on nonlinear bearing model and on linearized bearing model. Poincaré maps, phase trajectories, bifurcation diagrams, and cascade diagrams are used to illustrate the dynamics of the rotor with the two bearing models. The responses of these two kinds of systems under El Centro seismic wave are obtained. The acceleration data of the seismic wave are used as the input of base movements. The short bearing model is applied to express the nonlinear oil film force. Compared to the system with model of linearized bearing, the nonlinear bearing–rotor system can accurately reflect the dynamics of the system. Furthermore, trigonometric functions are employed to express the base movements, and the responses of nonlinear bearing–rotor system subject to the base movements are obtained. The fast Fourier transform is used to analyze the nonlinear bearing–rotor system with effects of the base movements. The results reveal not only the dynamic behavior of the rotor of the centrifugal pump supported by two nonlinear bearings, but also the responses of the nonlinear bearing–rotor system with the combined effects of centrifugal force and base movements.

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