Path Following for the Soft Origami Crawling Robot

2019 ◽  
Author(s):  
Oyuna Angatkina ◽  
Kimberly Gustafson ◽  
Aimy Wissa ◽  
Andrew Alleyne
Keyword(s):  
Autonomous Navigation ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Path Following ◽  
Search And Rescue ◽  
Soft Robots ◽  
Path Following Control ◽  
Straight Line ◽  
Pure Pursuit ◽  
Extensive Growth

Abstract Extensive growth of the soft robotics field has made possible the application of soft mobile robots for real world tasks such as search and rescue missions. Soft robots provide safer interactions with humans when compared to traditional rigid robots. Additionally, soft robots often contain more degrees of freedom than rigid ones, which can be beneficial for applications where increased mobility is needed. However, the limited number of studies for the autonomous navigation of soft robots currently restricts their application for missions such as search and rescue. This paper presents a path following technique for a compliant origami crawling robot. The path following control adapts the well-known pure pursuit method to account for the geometric and mobility constraints of the robot. The robot motion is described by a kinematic model that transforms the outputs of the pure pursuit into the servo input rotations for the robot. This model consists of two integrated sub-models: a lumped kinematic model and a segmented kinematic model. The performance of the path following approach is demonstrated for a straight-line following simulation with initial offset. Finally, a feedback controller is designed to account for terrain or mission uncertainties.

scholarly journals Autonomous Navigation of a Center-Articulated and Hydrostatic Transmission Rover using a Modified Pure Pursuit Algorithm in a Cotton Field

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4412
Author(s):  
Kadeghe Fue ◽  
Wesley Porter ◽  
Edward Barnes ◽  
Changying Li ◽  
Glen Rains
Keyword(s):  
Autonomous Navigation ◽  
Low Cost ◽  
Path Following ◽  
Absolute Error ◽  
Satellite System ◽  
Measurement Unit ◽  
Cotton Field ◽  
Cotton Production ◽  
Hydrostatic Transmission ◽  
Pure Pursuit

This study proposes an algorithm that controls an autonomous, multi-purpose, center-articulated hydrostatic transmission rover to navigate along crop rows. This multi-purpose rover (MPR) is being developed to harvest undefoliated cotton to expand the harvest window to up to 50 days. The rover would harvest cotton in teams by performing several passes as the bolls become ready to harvest. We propose that a small robot could make cotton production more profitable for farmers and more accessible to owners of smaller plots of land who cannot afford large tractors and harvesting equipment. The rover was localized with a low-cost Real-Time Kinematic Global Navigation Satellite System (RTK-GNSS), encoders, and Inertial Measurement Unit (IMU)s for heading. Robot Operating System (ROS)-based software was developed to harness the sensor information, localize the rover, and execute path following controls. To test the localization and modified pure-pursuit path-following controls, first, GNSS waypoints were obtained by manually steering the rover over the rows followed by the rover autonomously driving over the rows. The results showed that the robot achieved a mean absolute error (MAE) of 0.04 m, 0.06 m, and 0.09 m for the first, second and third passes of the experiment, respectively. The robot achieved an MAE of 0.06 m. When turning at the end of the row, the MAE from the RTK-GNSS-generated path was 0.24 m. The turning errors were acceptable for the open field at the end of the row. Errors while driving down the row did damage the plants by moving close to the plants’ stems, and these errors likely would not impede operations designed for the MPR. Therefore, the designed rover and control algorithms are good and can be used for cotton harvesting operations.

Composite finite-time straight-line path-following control of an underactuated surface vessel

2020 ◽  
Vol 357 (16) ◽  
pp. 11496-11517 ◽  
Author(s):  
Qiankang Hou ◽  
Li Ma ◽  
Shihong Ding ◽  
Xiaofei Yang ◽  
Xiangyong Chen
Keyword(s):  
Finite Time ◽  
Path Following ◽  
Path Following Control ◽  
Straight Line ◽  
Line Path ◽  
Surface Vessel

scholarly journals Modeling and Experimental Testing of an Unmanned Surface Vehicle with Rudderless Double Thrusters

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2051 ◽  
Author(s):  
Chunyue Li ◽  
Jiajia Jiang ◽  
Fajie Duan ◽  
Wei Liu ◽  
Xianquan Wang ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Testing ◽  
Path Following ◽  
Model Parameters ◽  
Crucial Issue ◽  
Unknown Parameters ◽  
Path Following Control ◽  
Differential Thrust ◽  
Three Degrees Of Freedom ◽  
Propeller Thrust

Motion control of unmanned surface vehicles (USVs) is a crucial issue in sailing performance and navigation costs. The actuators of USVs currently available are mostly a combination of thrusters and rudders. The modeling for USVs with rudderless double thrusters is rarely studied. In this paper, the three degrees of freedom (DOFs) dynamic model and propeller thrust model of this kind of USV were derived and combined. The unknown parameters of the propeller thrust model were reduced from six to two. In the three-DOF model, the propulsion of the USV was completely provided by the resultant force generated by double thrusters and the rotational moment was related to the differential thrust. It combined the propeller thrust model to represent the thrust in more detail. We performed a series of tests for a 1.5 m long, 50 kg USV, in order to obtain the model parameters through system identification. Then, the accuracy of the modeling and identification results was verified by experimental testing. Finally, based on the established model and the proportional derivative+line of sight (PD+LOS) control algorithm, the path-following control of the USV was achieved through simulations and experiments. All these demonstrated the validity and practical value of the established model.

Design of Strait-Line Tracking Controller of Under-Actuated USV Based on Back-Stepping Method and Feedback Compensation

2011 ◽  
Vol 48-49 ◽  
pp. 391-396
Author(s):  
Yu Long Ma ◽  
Jian Da Han ◽  
Yu Qing He
Keyword(s):  
High Performance ◽  
Mobile Robotics ◽  
Path Following ◽  
Main Research ◽  
Path Following Control ◽  
Straight Line ◽  
Feedback Compensation ◽  
Line Tracking ◽  
Line Path ◽  
Yaw Angle

Unmanned surface vehicle (USV) system has been one of main research directions in mobile robotics because it can be used in many situations. However, high performance path following control, especially straight line tracking control, has been one of the difficult problems in autonomous control of USV system. In this paper, we propose a new straight line path following control algorithm by combining yaw angle feedback and back-stepping technique and show its closed loop stability. The most absorbing advantage of the proposed controller is that it not only reserve the good performance of back-stepping controller but also bring much faster convergent rate, which is very important in real applications. The simulation results with respect to a training ship model have shown the feasibility and validity of the proposed method.

Virtual guidance-based finite-time path-following control of underactuated autonomous airship with error constraints and uncertainties

2020 ◽  
pp. 095441002096931
Author(s):  
Yan Wei ◽  
Pingfang Zhou ◽  
Yueying Wang ◽  
Dengping Duan ◽  
Zheng Chen
Keyword(s):  
Finite Time ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Small Neighborhood ◽  
Path Following ◽  
Coordinate Frame ◽  
Control Approach ◽  
Finite Time Stability ◽  
Path Following Control ◽  
Following Error

This paper addresses the finite-time three-dimensional path-following control problem for underactuated autonomous airship with error constraints and uncertainties. First, a five degrees-of-freedom path-following error model in the Serret-Frenet coordinate frame is established. By applying the finite-time stability theory, a virtual guidance-based finite-time adaptive neural backstepping path-following control approach is proposed. Barrier Lyapunov functions (BLFs) are introduced to deal with attitude error constraints. Neural networks (NNs) are presented to compensate for the uncertainties. To prevent the “explosion of complexity” in the design of the backstepping method, a finite-time convergent differentiator (FTCD) is introduced to estimate the time derivatives of virtual control signals. Stability analysis showed that all closed-loop signals are uniformly ultimately bounded, the constrained requirements on the airship attitude errors are never violated, and the path-following errors converge to a small neighborhood of the origin in a finite time. At last, simulation studies are provided to demonstrate the effectiveness of the proposed control approach.

Pure Pursuit Guidance for Car-Like Ground Vehicle Trajectory Tracking

2017 ◽  
Author(s):  
Yuanyan Chen ◽  
J. Jim Zhu
Keyword(s):  
Trajectory Tracking ◽  
Degrees Of Freedom ◽  
Tracking Error ◽  
Path Following ◽  
Trajectory Design ◽  
Wheeled Mobile Robots ◽  
Design Algorithm ◽  
Pure Pursuit ◽  
Trajectory Tracking Controller ◽  
Self Driving Cars

Trajectory tracking guidance and control for nonholonomic (car-like) Autonomous Ground Vehicles (AGV), such as self-driving cars and car-like wheeled mobile robots, is a more challenging control problem than path following control, because the latter does not impose a speed requirement on the vehicle motion. The tracking error dynamics along the nominal path are nonlinear and time-varying in nature, which need to be exponentially stabilized. This paper presents a Line-of-Sight (LOS) Pure-Pursuit Guidance (PPG) trajectory design algorithm that generates a three Degrees of Freedom (DOF) spatial trajectory for an AGV equipped with a 3DOF trajectory tracking controller. The LOS PPG can be used for cooperative, passive (neutral) and adversarial tracking tasks, such as, respectively, formation driving, autonomous lane keeping with speed requirement, and chasing an evading vehicle. The algorithm is verified with computer simulations on a 1/6 scale electric car model, and will be further validated on that model car in the near future.

scholarly journals Planar kinematics analysis of a snake-like robot

Robotica ◽  
2013 ◽  
Vol 32 (5) ◽  
pp. 659-675 ◽  
Author(s):  
Lounis Douadi ◽  
Davide Spinello ◽  
Wail Gueaieb ◽  
Hassan Sarfraz
Keyword(s):  
Autonomous Navigation ◽  
Degrees Of Freedom ◽  
Optimization Problem ◽  
Path Following ◽  
Non Destructive Testing ◽  
Dimensional Synthesis ◽  
Destructive Testing ◽  
Kinematic Constraint ◽  
Revolute Joints ◽  
Non Destructive

SUMMARYThis paper presents the kinematics of a planar multibody vehicle which is aimed at the exploration, data collection, non-destructive testing and general autonomous navigation and operations in confined environments such as pipelines. The robot is made of several identical modules hinged by passive revolute joints. Every module is actuated with four active revolute joints and can be regarded as a parallel mechanism on a mobile platform. The proposed kinematics allows to overcome the nonholonomic kinematic constraint, which characterizes typical wheeled robots, resulting into a higher number of degrees of freedom and therefore augmented actuation inputs. Singularities in the kinematics of the modules are analytically identified. We present the dimensional synthesis of the length of the arms obtained as the solution of an optimization problem with respect to a suitable dexterity index. Simulation results illustrate a kinematic control path following inside pipes. Critical scenarios such as 135° elbows and concentric restriction are explored. Path following shows the kinematic capability of deployment of the robot for autonomous operations in pipelines, with feedback implemented by on-board sensors.

scholarly journals High-speed path following control of skid-steered vehicles

2019 ◽  
Vol 38 (9) ◽  
pp. 1124-1148 ◽  
Author(s):  
Goran Huskić ◽  
Sebastian Buck ◽  
Matthieu Herrb ◽  
Simon Lacroix ◽  
Andreas Zell
Keyword(s):  
High Speed ◽  
Actuator Saturation ◽  
Kinematic Model ◽  
Path Following ◽  
Lyapunov Theory ◽  
Path Following Control ◽  
Control Scheme ◽  
Combined Solution ◽  
Nonlinear Control Law ◽  
Following Error

We present a robust control scheme for skid-steered vehicles that enables high-speed path following on challenging terrains. First, a kinematic model with experimentally identified parameters is constructed to describe the terrain-dependent motion of skid-steered vehicles. Using Lyapunov theory, a nonlinear control law is defined, guaranteeing the convergence of the vehicle to the path. To allow smooth and accurate motion at higher speeds, an additional linear velocity control scheme is proposed, which takes actuator saturation, path following error, and reachable curvatures into account. The combined solution is experimentally evaluated and compared against two state-of-the-art algorithms, by using two different robots on several different terrain types, at different speeds. A Robotnik Summit XL robot is tested on three different terrain types and two different paths at speeds up to [Formula: see text] m/s. A Segway RMP 440 robot is tested on three different terrain types and two different path types at speeds up to [Formula: see text] m/s.

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