scholarly journals A Quadruped Robot with the Wooden Body for Static Locomotion in a Controlled Environment

2020 ◽  
Author(s):  
Muhammad Bilal Khan ◽  
Ahmad Kamal Khan
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Low Cost ◽  
Control Design ◽  
Quadruped Robot ◽  
Legged Robots ◽  
Controlled Environment ◽  
Robot Design ◽  
Classroom Setting

We present the design and overall development of an eight degrees of freedom (DOF) based Bioinspired Quadruped Robot (BiQR). The robot is designed with a skeleton made of cedar wood. The wooden skeleton is based on exploring the potential of cedar wood to be a choice for legged robots’ design. With a total weight of 1.19 kg, the robot uses eight servo motors that run the position control. Relying on the inverse kinematics, the control design enables the robot to perform the walk gait-based locomotion in a controlled environment. The robot has two main aspects: 1) the initial wooden skeleton development of the robot showing it to be an acceptable choice for robot design, 2) the robot’s applicability as a low-cost legged platform to test the locomotion in a laboratory or a classroom setting.

scholarly journals A Quadruped Robot with the Wooden Body for Static Locomotion in a Controlled Environment

2020 ◽  
Author(s):  
Muhammad Bilal Khan
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Low Cost ◽  
Control Design ◽  
Quadruped Robot ◽  
Legged Robots ◽  
Controlled Environment ◽  
Robot Design ◽  
Classroom Setting

We present the design and overall development of an eight degrees of freedom (DOF) based Bioinspired Quadruped Robot (BiQR). The robot is designed with a skeleton made of cedar wood. The wooden skeleton is based on exploring the potential of cedar wood to be a choice for legged robots’ design. With a total weight of 1.19 kg, the robot uses eight servo motors that run the position control. Relying on the inverse kinematics, the control design enables the robot to perform the walk gait-based locomotion in a controlled environment. The robot has two main aspects: 1) the initial wooden skeleton development of the robot showing it to be an acceptable choice for robot design, 2) the robot’s applicability as a low-cost legged platform to test the locomotion in a laboratory or a classroom setting.

scholarly journals A Nonlinear Magnetic Stabilization Control Design for an Externally Manipulated DC Motor: An Academic Low-Cost Experimental Platform

Machines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 101
Author(s):  
Leonardo Acho
Keyword(s):  
Hall Effect ◽  
Position Control ◽  
Low Cost ◽  
Time Derivative ◽  
Control Design ◽  
Dc Motor ◽  
Flexible Beam ◽  
Experimental Platform ◽  
Hall Effect Sensor ◽  
Vibrational Control

The main objective of this paper is to present a position control design to a DC-motor, where the set-point is externally supplied. The controller is conceived by using vibrational control theory and implemented by just processing the time derivative of a Hall-effect sensor signal. Vibrational control is robust against model uncertainties. Hence, for control design, a simple mathematical model of a DC-Motor is invoked. Then, this controller is realized by utilizing analog electronics via operational amplifiers. In the experimental set-up, one extreme of a flexible beam attached to the motor shaft, and with a permanent magnet fixed on the other end, is constructed. Therefore, the control action consists of externally manipulating the flexible beam rotational position by driving a moveable Hall-effect sensor that is located facing the magnet. The experimental platform results in a low-priced device and is useful for teaching control and electronic topics. Experimental results are evidenced to support the main paper contribution.

scholarly journals Soft Spherical Tensegrity Robot Design Using Rod-Centered Actuation and Control

2016 ◽  
Author(s):  
Lee-Huang Chen ◽  
Kyunam Kim ◽  
Ellande Tang ◽  
Kevin Li ◽  
Richard House ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Low Cost ◽  
Space Exploration ◽  
Robot Design ◽  
The Novel ◽  
Flexible Design ◽  
Spherical Robot ◽  
Potential Benefits ◽  
And Performance ◽  
And Control

This paper presents the design, analysis and testing of a fully actuated modular spherical tensegrity robot for co-robotic and space exploration applications. Robots built from tensegrity structures (composed of pure tensile and compression elements) have many potential benefits including high robustness through redundancy, many degrees of freedom in movement and flexible design. However to fully take advantage of these properties a significant fraction of the tensile elements should be active, leading to a potential increase in complexity, messy cable and power routing systems and increased design difficulty. Here we describe an elegant solution to a fully actuated tensegrity robot: The TT-3 (version 3) tensegrity robot, developed at UC Berkeley, in collaboration with NASA Ames, is a lightweight, low cost, modular, and rapidly prototyped spherical tensegrity robot. This robot is based on a ball-shaped six-bar tensegrity structure and features a unique modular rod-centered distributed actuation and control architecture. This paper presents the novel mechanism design, architecture and simulations of TT-3, the first untethered, fully actuated cable-driven six-bar tensegrity spherical robot ever built and tested for mobility. Furthermore, this paper discusses the controls and preliminary testing performed to observe the system’s behavior and performance.

Control Design and Task Performance in Endoscopic Teleoperation

2000 ◽  
Vol 9 (3) ◽  
pp. 256-267 ◽  
Author(s):  
Ori Ben-Porat ◽  
Moshe Shoham ◽  
Joachim Meyer
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Control Design ◽  
Control Mode ◽  
Robotic Arm ◽  
Task Completion ◽  
Motor Mapping ◽  
Surgical Tool ◽  
Acquisition Task ◽  
Visual Motor

Endoscopic surgery, while offering considerable gains for the patient, has created new difficulties for the surgeon. One problem is the fulcrum effect, which causes the movement of a surgical instrument, as seen on the monitor, to be in the opposite direction to the movement of the surgeon's hand. The problem has been shown to impede the acquisition of endoscopic skills. Teleoperated robotic arms may circumvent this problem by allowing different control-response relations. Four alternative control designs of a teleoperated device were compared in a simulated endoscopic task. A rigid teleoperated robotic arm with two degrees of freedom representing a surgical tool was coupled to a joystick in a position control mode. Feedback was provided through a video display. Participants without prior experience in endoscopy performed a target acquisition task, first by pointing the robotic arm at the targets, and later by maneuvering an object. Performance was measured under four different combinations of visual-motor mapping (normal/reversed), and the joystick's orientation (upwards/downwards). Task completion time under normal visual-motor mapping was found to be significantly shorter than under reversed visual-motor mapping, emphasizing the potential advantage of a teleoperated endoscopic system. The joystick's orientation affected the maneuvering of an object under only the reversed visual-motor mapping, implying that the positioning of a surgical tool and the manipulation of tissues or objects with the tool may be differentially affected by the control design.

Four Degrees of Freedom Robot Arm, Low-Cost Competition in the Design and Development

2013 ◽  
Vol 5 (1) ◽  
pp. 50-65 ◽  
Author(s):  
Liu Hongcong
Keyword(s):  
Inverse Kinematics ◽  
Optical Materials ◽  
Degrees Of Freedom ◽  
Low Cost ◽  
Serial Communication ◽  
Materials Processing ◽  
Robot Arm ◽  
Servo Motor ◽  
Industrial Labor ◽  
Normal Work

The focus of this work is to design, develop and implement enhanced control and competitive robot arm thick and short cost. Design of four degree of freedom and talent of robot arm is to complete the accurate and simple tasks, such as optical materials processing, will be integrated into the mobile platform, as an assistant for the industrial labor force. Between the robot arm equipped with weapons and arm movements associated with the plurality of servo motor. Servo motor, encoder, so as to realize no controller includes. To control the robot, using Lab view, to the computation of the inverse kinematics of serial communication and proper angle, a micro controller, servo motor and drive ability of modify the location, velocity and acceleration. The robot arm was tested and verified, results show that, its normal work.

A 3D stable trot of a quadruped robot over uneven terrains

2016 ◽  
Vol 231 (3) ◽  
pp. 555-573 ◽  
Author(s):  
Mahdi Khorram ◽  
S Ali A Moosavian
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Quadruped Robot ◽  
Legged Robots ◽  
Whole Body ◽  
Main Body ◽  
Stable Gait ◽  
Three Dimensional Space

Legged robots have superior advantages rather than wheeled robots for moving over uneven terrains in the presence of various obstacles. The design of an appropriate path for the main body and legs is an important issue for such robots especially on the uneven terrains. In this paper, the focus is to develop a stable gait for a quadruped robot to trot on uneven terrains. First, a stability condition is developed for a whole-body quadruped robot over uneven terrains based on avoiding the tumbling. By using a simple model, a point with zero moments is calculated in the three-dimensional space. Then, the reference path of this point is determined so that the tumbling moments become zero. The path of the main body will be calculated by using an optimal controller. The main feature of the proposed gait generation framework is that the height of robot can change continuously and stably on uneven terrains. To evaluate the robot stability, the tumbling moments around diagonal lines are calculated and some methods are proposed to reduce these moments to improve the robot stability. The tip of swing foot is also planned to avoid any collision with the environment. The proposed method will be demonstrated using an 18-Degrees of freedom (DOF) quadruped robot in simulation and experimental studies. The experimental setup is a small-size quadruped robot, which is composed of a rectangular plate as its main body with four legs that each one has three active joints with DC servo motors. Obtained results reveal that the robot can trot on uneven terrains stably. Besides, the comparison with the previous methods approves the merits of proposed algorithm on uneven terrains.

scholarly journals Soft Spherical Tensegrity Robot Design Using Rod-Centered Actuation and Control

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Lee-Huang Chen ◽  
Kyunam Kim ◽  
Ellande Tang ◽  
Kevin Li ◽  
Richard House ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Low Cost ◽  
Space Exploration ◽  
Robot Design ◽  
The Novel ◽  
Flexible Design ◽  
Preliminary Testing ◽  
Potential Benefits ◽  
And Performance ◽  
And Control

This paper presents the design, analysis, and testing of a fully actuated modular spherical tensegrity robot for co-robotic and space exploration applications. Robots built from tensegrity structures (composed of pure tensile and compression elements) have many potential benefits including high robustness through redundancy, many degrees-of-freedom in movement and flexible design. However, to take full advantage of these properties, a significant fraction of the tensile elements should be active, leading to a potential increase in complexity, messy cable, and power routing systems and increased design difficulty. Here, we describe an elegant solution to a fully actuated tensegrity robot: The TT-3 (version 3) tensegrity robot, developed at UC Berkeley, in collaboration with NASA Ames, is a lightweight, low cost, modular, and rapidly prototyped spherical tensegrity robot. This robot is based on a ball-shaped six-bar tensegrity structure and features a unique modular rod-centered distributed actuation and control architecture. This paper presents the novel mechanism design, architecture, and simulations of TT-3, an untethered, fully actuated cable-driven six-bar spherical tensegrity robot. Furthermore, this paper discusses the controls and preliminary testing performed to observe the system's behavior and performance and is evaluated against previous models of tensegrity robots developed at UC Berkeley and elsewhere.

Modeling and base parameters identification of legged robots

Robotica ◽  
2021 ◽  
pp. 1-15
Author(s):  
Xu Chang ◽  
Honglei An ◽  
Hongxu Ma
Keyword(s):  
Degrees Of Freedom ◽  
Quadruped Robot ◽  
Modeling Method ◽  
Parameters Identification ◽  
Legged Robots ◽  
Dynamic Parameters ◽  
End Effector ◽  
Identification Method ◽  
Base Parameters

Abstract This paper first uses a decoupling modeling method to model legged robots. The method groups all the degrees of freedom according to the number of limbs, regarding each limb as a manipulator with serial structure, which greatly reduces the number of dynamic parameters that need to be identified simultaneously. On this basis, a step-by-step identification method from the end-effector link to the base link, referred to as “E-B” identification method, is proposed. Simulation verification is carried out on a quadruped robot with 16 degrees of freedom in Gazebo, and the validity of the method proposed is discussed.

Electronics-free pneumatic circuits for controlling soft-legged robots

2021 ◽  
Vol 6 (51) ◽  
pp. eaay2627 ◽  
Author(s):  
Dylan Drotman ◽  
Saurabh Jadhav ◽  
David Sharp ◽  
Christian Chan ◽  
Michael T. Tolley
Keyword(s):  
Degrees Of Freedom ◽  
Low Cost ◽  
Legged Robots ◽  
Walking Robots ◽  
Memory Element ◽  
Walking Gait ◽  
Locomotion Speed ◽  
Control Circuits ◽  
Actuation Systems ◽  
Constant Source

Pneumatically actuated soft robots have recently shown promise for their ability to adapt to their environment. Previously, these robots have been controlled with electromechanical components, such as valves and pumps, that are typically bulky and expensive. Here, we present an approach for controlling the gaits of soft-legged robots using simple pneumatic circuits without any electronic components. This approach produces locomotive gaits using ring oscillators composed of soft valves that generate oscillating signals analogous to biological central pattern generator neural circuits, which are acted upon by pneumatic logic components in response to sensor inputs. Our robot requires only a constant source of pressurized air to power both control and actuation systems. We demonstrate this approach by designing pneumatic control circuits to generate walking gaits for a soft-legged quadruped with three degrees of freedom per leg and to switch between gaits to control the direction of locomotion. In experiments, we controlled a basic walking gait using only three pneumatic memory elements (valves). With two oscillator circuits (seven valves), we were able to improve locomotion speed by 270%. Furthermore, with a pneumatic memory element we designed to mimic a double-pole double-throw switch, we demonstrated a control circuit that allowed the robot to select between gaits for omnidirectional locomotion and to respond to sensor input. This work represents a step toward fully autonomous, electronics-free walking robots for applications including low-cost robotics for entertainment and systems for operation in environments where electronics may not be suitable.

scholarly journals Reconstruction of Relative Phase of Self-Transmitting Devices by Using Multiprobe Solutions and Non-Convex Optimization

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2459
Author(s):  
Rubén Tena Sánchez ◽  
Fernando Rodríguez Varela ◽  
Lars J. Foged ◽  
Manuel Sierra Castañer
Keyword(s):  
Iterative Algorithm ◽  
Degrees Of Freedom ◽  
Relative Phase ◽  
Low Cost ◽  
Initial Guess ◽  
Noise Model ◽  
Medium Size ◽  
Phase Reconstruction ◽  
Linear Combinations ◽  
Iterative Optimization Algorithm

Phase reconstruction is in general a non-trivial problem when it comes to devices where the reference is not accessible. A non-convex iterative optimization algorithm is proposed in this paper in order to reconstruct the phase in reference-less spherical multiprobe measurement systems based on a rotating arch of probes. The algorithm is based on the reconstruction of the phases of self-transmitting devices in multiprobe systems by taking advantage of the on-axis top probe of the arch. One of the limitations of the top probe solution is that when rotating the measurement system arch, the relative phase between probes is lost. This paper proposes a solution to this problem by developing an optimization iterative algorithm that uses partial knowledge of relative phase between probes. The iterative algorithm is based on linear combinations of signals when the relative phase is known. Phase substitution and modal filtering are implemented in order to avoid local minima and make the algorithm converge. Several noise-free examples are presented and the results of the iterative algorithm analyzed. The number of linear combinations used is far below the square of the degrees of freedom of the non-linear problem, which is compensated by a proper initial guess. With respect to noisy measurements, the top probe method will introduce uncertainties for different azimuth and elevation positions of the arch. This is modelled by considering the real noise model of a low-cost receiver and the results demonstrate the good accuracy of the method. Numerical results on antenna measurements are also presented. Due to the numerical complexity of the algorithm, it is limited to electrically small- or medium-size problems.

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