Large Deformation of Flexure Couplings for Robotic Arm Joints

2017 ◽  
Author(s):  
Nicola Y. Bailey ◽  
Chris Lusty ◽  
Patrick S. Keogh
Keyword(s):  
Open Loop ◽  
Small Scale ◽  
Nonlinear Mathematical Model ◽  
Loop Control ◽  
Multiple Paths ◽  
Deformable Structure ◽  
Scale Motion ◽  
Multi Body ◽  
Control Methodology ◽  
Limited Motion

Conventional multi-body mechanisms used in robotics and automated machinery can have limited motion due to the bearing and transmission parts. Replacing a traditional bearing joint with a compact deformable structure (flexure coupling) can improve the performance envelope for a mechanism. A dynamic nonlinear mathematical model is derived for a mechanism comprising a flexure coupling, which can undergo large deformations, connected to a rigid link. Direct actuation of the mechanism is assumed in three directions and an open-loop control methodology is designed to regulate the actuation forces to achieve a prescribed path with precise and repeatable small scale motion. A mechanism containing a flexure coupling is examined and compared to that of an ideal hinge joint. The results show that a flexure coupling allows an increased range of motion for the mechanism compared to a hinge coupling and can have multiple paths in the x and y direction for a prescribed angle trajectory at the end of the mechanism.

scholarly journals Design and Analysis of Multi-Device Interleaved Boost Converter Driving an Induction Motor

2021 ◽  
Vol 850 (1) ◽  
pp. 012036
Author(s):  
R Latha ◽  
S Adharsh Babu ◽  
M Vivek Kumar
Keyword(s):  
Induction Motor ◽  
Electric Vehicles ◽  
Closed Loop ◽  
Boost Converter ◽  
Open Loop ◽  
Power Electronic ◽  
Loop Control ◽  
Interleaved Boost Converter ◽  
Control Methodology ◽  
Electronic Interface

Abstract Electric vehicles are the future of mobility solutions. The electric vehicles are driven by an electric motor with the help of a power electronic interface. The power electronic interface needs to be designed in an efficient way both in mechanical and electrical aspects. This paper proposes the concept of design, simulation and analysis of a 10 kW Multi-Device Interleaved DC-DC Boost Converter (MDIBC) to drive a 4 kW Induction Motor. The motor is driven from the MDIBC through an inverter with SPWM technique. The variation in DC link voltage due to motor is controlled and stabilized to give a constant DC of 400 V. MDIBC consists of semi-controlled switches topology excited by Phase Shifted PWM technique to reduce the ripple current in interleaving inductors. The dual loop control methodology using PI controller is adopted to reduce the ripple in input inductor current and DC link voltage. The open loop simulation and closed loop simulation are done in MATLAB Simulink environment. The simulation results show that the overshoots and steady state error in inductor currents and output voltage are reduced in addition with reduction in current and voltage ripples.

Small Scale Wind Generation System: Part II – A Novel Quasi-Z-Source Inverter and FRG-QZSI-Micro Grid Interface

2017 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
M. Ramkumar ◽  
K. N. Srinivas
Keyword(s):  
Control Strategies ◽  
Research Work ◽  
Open Loop ◽  
Small Scale ◽  
Loop Control ◽  
Power Injection ◽  
System Part ◽  
Micro Grid ◽  
Wind Generation System ◽  
And Control

<p>This paper proposes modelling, analysis and control of a small scale wind energy conversion system employing a direct driven Flux Reversal Generator (FRG) connected to the micro grid through a quasi-Z-source inverter (QZSI). This entire research is made up of two major parts viz., FRG and QZSI. In the part I report of this research work, the role of FRG has been thoroughly modelled and verified. In this part II, the modelling and analysis of QZSI for this purpose is presented. In addition, the modified space vector PWM (SVPWM) technique is proposed in this paper to satisfy the shoot-through characteristic of QZSI, which is a novel. The interface of FRG and QZSI to inject power in to micro grid has been finally presented. The simulation results are validated with the analytical results. Section I discusses the open loop control of QZSI. The mathematical modelling of QZSI for this purpose is given and analytically validated. This flowed by section II in which the proposed SVPWM is presented. The procedure to obtain triggering pulses using this proposed modulation technique is discussed. Section III presents closed loop control strategies for QZSI. Section IV presents the micro grid<br />inte face and power injection.</p>

Joystick Steering in Recreational Boats Using L1 Adaptive Control

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
John A. Bayless ◽  
Phillip A. Voglewede
Keyword(s):  
Adaptive Control ◽  
Scale Model ◽  
Small Scale ◽  
Physical Parameters ◽  
Velocity Control ◽  
Loop Control ◽  
L1 Adaptive Control ◽  
The Cost ◽  
Control Methodology ◽  
Joystick Control

Abstract This paper addresses the challenge of commissioning recreational boats with joystick control systems when the boat's physical parameters are not known. The work was conducted through matlab simulations and scale-model physical testing. The outcome is a working nonlinear, closed-loop control methodology shown on a small-scale prototype boat. The control methodology, L1 adaptive control (L1AC), provides adaptive velocity and angular velocity control. The control system delivers performance levels that could reduce the cost of commissioning boats with joystick control, improve overall performance, and potentially enable the technology to support new boat markets.

scholarly journals A Machine Learning Approach for the Segmentation of Driving Maneuvers and its Application in Autonomous Parking

2017 ◽  
Vol 7 (4) ◽  
pp. 243-255 ◽  
Author(s):  
Gennaro Notomista ◽  
Michael Botsch
Keyword(s):  
Classification System ◽  
Autonomous Vehicle ◽  
Autonomous Driving ◽  
Ensemble Classifier ◽  
Classification Performance ◽  
Open Loop ◽  
Training Data ◽  
Small Scale ◽  
Data Set ◽  
Loop Control

AbstractA classification system for the segmentation of driving maneuvers and its validation in autonomous parking using a small-scale vehicle are presented in this work. The classifiers are designed to detect points that are crucial for the path-planning task, thus enabling the implementation of efficient autonomous parking maneuvers. The training data set is generated by simulations using appropriate vehicle-dynamics models and the resulting classifiers are validated with the small-scale autonomous vehicle. To achieve both a high classification performance and a classification system that can be implemented on a microcontroller with limited computational resources, a two-stage design process is applied. In a first step an ensemble classifier, the Random Forest (RF) algorithm, is constructed and based on the RF-kernel a General Radial Basis Function (GRBF) classifier is generated. The GRBF-classifier is integrated into the small-scale autonomous vehicle leading to excellent performance in parallel-, cross- and oblique-parking maneuvers. The work shows that segmentation using classifies and open-loop control are an efficient approach in autonomous driving for the implementation of driving maneuvers.

Multi-Body Dynamics Model of a Tracked Vehicle Using a Towing Winch for Optimal Mobility Control and Terrain Identification

2016 ◽  
Author(s):  
Joshua T. Cook ◽  
Laura Ray ◽  
James Lever
Keyword(s):  
Hydraulic System ◽  
Open Loop ◽  
Mobility Control ◽  
Dynamics Model ◽  
Tracked Vehicle ◽  
Loop Control ◽  
Power Load ◽  
Body Dynamics ◽  
Simulation Results ◽  
Multi Body

This paper presents a generalized, multi-body dynamics model for a tracked vehicle equipped with a winch for towing operations. The modeling approach couples existing formulations in the literature for the powertrain components and the vehicle-terrain interaction to provide a comprehensive model that captures the salient features of terrain trafficability. This coupling is essential for making realistic predictions of the vehicle’s mobility capabilities due to the power-load relationship at the engine output. Simulation results are presented jointly with experimental data to validate these dynamics under conditions where no action is taken by the winch. Extended modeling includes dynamics of the hydraulic system that powers the winch so that the limitation of the winch as an actuator and the load it puts on the engine are realized. A second set of simulation results show that for a set of open loop control actions by the winch, the vehicle is able to maintain its mobility in low traction terrain by paying the towed load in and out.

Open-loop control of compensation for optical propagation through a turbulent shear flow

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen
Keyword(s):  
Shear Flow ◽  
Open Loop ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Open Loop Control ◽  
Loop Control ◽  
Optical Propagation

scholarly journals Sensuator: A Hybrid Sensor–Actuator Approach to Soft Robotic Proprioception Using Recurrent Neural Networks

Actuators ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 30
Author(s):  
Pornthep Preechayasomboon ◽  
Eric Rombokas
Keyword(s):  
Neural Networks ◽  
Recurrent Neural Networks ◽  
Linear Models ◽  
Open Loop ◽  
Proof Of Concept ◽  
State Estimator ◽  
Loop Control ◽  
Practical Applications ◽  
Soft Actuator ◽  
The Cost

Soft robotic actuators are now being used in practical applications; however, they are often limited to open-loop control that relies on the inherent compliance of the actuator. Achieving human-like manipulation and grasping with soft robotic actuators requires at least some form of sensing, which often comes at the cost of complex fabrication and purposefully built sensor structures. In this paper, we utilize the actuating fluid itself as a sensing medium to achieve high-fidelity proprioception in a soft actuator. As our sensors are somewhat unstructured, their readings are difficult to interpret using linear models. We therefore present a proof of concept of a method for deriving the pose of the soft actuator using recurrent neural networks. We present the experimental setup and our learned state estimator to show that our method is viable for achieving proprioception and is also robust to common sensor failures.

scholarly journals Modified LQG/LTR Control Methodology in Active Structural Control

2003 ◽  
Vol 22 (2) ◽  
pp. 97-108 ◽  
Author(s):  
Yan Sheng ◽  
Chao Wang ◽  
Ying Pan ◽  
Xinhua Zhang
Keyword(s):  
Structural Control ◽  
Signal To Noise Ratio ◽  
Open Loop ◽  
Control Force ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Control Approach ◽  
Active Structural Control ◽  
Loop Transfer Recovery ◽  
Control Methodology

This paper presents a new active structural control design methodology comparing the conventional linear-quadratic-Gaussian synthesis with a loop-transfer-recovery (LQG/LTR) control approach for structures subjected to ground excitations. It results in an open-loop stable controller. Also the closed-loop stability can be guaranteed. More importantly, the value of the controller's gain required for a given degree of LTR is orders of magnitude less than what is required in the conventional LQG/LTR approach. Additionally, for the same value of gain, the proposed controller achieves a much better degree of recovery than the LQG/LTR-based controller. Once this controller is obtained, the problems of control force saturation are either eliminated or at least dampened, and the controller band-width is reduced and consequently the control signal to noise ratio at the input point of the dynamic system is increased. Finally, numerical examples illustrate the above advantages.

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