Position and Force Control of Micromanipulatorwith Six Degrees of Freedom Using Piezoelectric Actuators

1991 ◽  
Vol 3 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Toshio Fukuda ◽  
◽  
Motohiro Fujiyoshi ◽  
Fumihito Arai ◽  
Hideo Matsuura ◽  
...  
Keyword(s):  
Force Control ◽  
Fuzzy System ◽  
Degrees Of Freedom ◽  
Force Feedback ◽  
Piezoelectric Actuators ◽  
Feedback System ◽  
Six Degrees Of Freedom ◽  
Variable Gain ◽  
And Control ◽  
Better Than

This paper deals with the mechanism and control of a micromanipulator with six degrees of freedom (6 D.O.F.) aimed at applications in biotechnology and microsurgery. Since operations in these fields develop rapidly and are complicated, a dexterous micromanipulation system has long been desired. This paper proposes a 6 D.O.F micromanipulator to make such work easier. The manipulator has the following features: (1) The manipulator has 6 D.O.F. The tip of this manipulator can move along three axes, and also can rotate along each axis. (2) This micromanipulator is very small and light, since it is made of PZT actuators. (3) Since it has a position and force feedback system, it can control desired poses and forces. (4) A variable gain feedback system, similar to a fuzzy system, is employed here, and hence the system performs better than a fixed gain feedback system. These technical merits will make it possible to operate the micromanipulator in much more complicated environments under a microscope.

Control of processing at multi-tool two-support setup

2020 ◽  
pp. 67-73
Author(s):  
N.D. YUsubov ◽  
G.M. Abbasova
Keyword(s):  
Degrees Of Freedom ◽  
Factor Model ◽  
Angular Displacement ◽  
Factor Models ◽  
Technological System ◽  
Displacement Control ◽  
Model Accuracy ◽  
Six Degrees Of Freedom ◽  
Angular Displacements ◽  
And Control

The accuracy of two-tool machining on automatic lathes is analyzed. Full-factor models of distortions and scattering fields of the performed dimensions, taking into account the flexibility of the technological system on six degrees of freedom, i. e. angular displacements in the technological system, were used in the research. Possibilities of design and control of two-tool adjustment are considered. Keywords turning processing, cutting mode, two-tool setup, full-factor model, accuracy, angular displacement, control, calculation [email protected]

Design, Construction and Control of a Remotely Operated Vehicle (ROV)

2011 ◽  
Author(s):  
Alireza Marzbanrad ◽  
Jalil Sharafi ◽  
Mohammad Eghtesad ◽  
Reza Kamali
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Remotely Operated Vehicle ◽  
Six Degrees Of Freedom ◽  
Depth Sensors ◽  
Control Schemes ◽  
On Line ◽  
Operation Unit ◽  
And Control ◽  
Design Construction

This is report of design, construction and control of “Ariana-I”, an Underwater Remotely Operated Vehicle (ROV), built in Shiraz University Robotic Lab. This ROV is equipped with roll, pitch, heading, and depth sensors which provide sufficient feedback signals to give the system six degrees-of-freedom actuation. Although its center of gravity and center of buoyancy are positioned in such a way that Ariana-I ROV is self-stabilized, but the combinations of sensors and speed controlled drivers provide more stability of the system without the operator involvement. Video vision is provided for the system with Ethernet link to the operation unit. Control commands and sensor feedbacks are transferred on RS485 bus; video signal, water leakage alarm, and battery charging wires are provided on the same multi-core cable. While simple PI controllers would improve the pitch and roll stability of the system, various control schemes can be applied for heading to track different paths. The net weight of ROV out of water is about 130kg with frame dimensions of 130×100×65cm. Ariana-I ROV is designed such that it is possible to be equipped with different tools such as mechanical arms, thanks to microprocessor based control system provided with two directional high speed communication cables for on line vision and operation unit.

Demonstration of aircraft dynamic stability and response for aeronautical engineering students

1994 ◽  
Vol 98 (975) ◽  
pp. 192-193
Author(s):  
A.W. Bloy
Keyword(s):  
Dynamic Stability ◽  
Degrees Of Freedom ◽  
Engineering Students ◽  
Six Degrees Of Freedom ◽  
Stability And Control ◽  
Good Grasp ◽  
Aircraft Motion ◽  
Aeronautical Engineering ◽  
And Control ◽  
Aircraft Stability And Control

The teaching of aircraft stability and control at university usually progresses to the complexity of six degrees of freedom with a large array of aerodynamic, gravitational and inertial terms. It is therefore essential to ensure that students have a good grasp of fundamental dynamic characteristics such as damping and natural frequency, and any demonstration in which students observe aircraft motion is particularly helpful. At Manchester University this is achieved by a windtunnel demonstration of aircraft dynamic stability and response in pitch to a sinusoidal gust generator.

The Integrated Mission Simulator

SIMULATION ◽  
1964 ◽  
Vol 2 (2) ◽  
pp. R-9-R-23
Author(s):  
Edward E. Markson ◽  
John L. Stricker
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Landing Site ◽  
Euler Angle ◽  
Space Mission ◽  
Six Degrees Of Freedom ◽  
Guidance And Control ◽  
Manned Space ◽  
And Control ◽  
Guidance Technique

Space mission simulator programs may be divided into two broad categories: (1) training tools (quali tative devices often simulating a continuous mission), and (2) laboratory tools (quantitative devices treating the mission in phases, each phase being programmed separately to obtain optimum scaling). This paper describes the development of an analog program capable of continuously simulating an entire lunar mission in six degrees of freedom with high resolu tion throughout. The reported work logically traces the program development through the equations of motion, the guidance and control equations, and the analog mechanization. The translation equations are de veloped using a modified form of Encke's method; two reference origins are utilized at the two points of primary interest—the landing site and the target vehicle—such that the displacements are approach ing a minimum in the regions where the highest reso lution is required. The variables are rescaled as this region is approached to obtain maximum accuracy. Relays, stepping switches and diode gates are used for rescaling and to re-reference origins. A particular Euler angle sequence is selected based on matrix validity criteria applied to the mission. A previously reported guidance technique is shown to be appli cable to all phases of the mission. It is concluded that the method demonstrated in this paper leads to minimum computer loading for simulating a manned space mission without program discontinuities. Supporting data include an analog- computed trajectory representative of a long-dura tion mission, which is compared in detail with a digital solution.

Model Tests for Safe-Return-to-Port of a Damaged Ship in Waves

2015 ◽  
Author(s):  
Jeonghwa Seo ◽  
Cristobal Santiago Bravo ◽  
Shin Hyung Rhee
Keyword(s):  
Degrees Of Freedom ◽  
Feedback System ◽  
Model Tests ◽  
Measurement Unit ◽  
Test Model ◽  
Motion Response ◽  
Six Degrees Of Freedom ◽  
Heading Angle ◽  
Wave Conditions ◽  
Damaged Ship

A series of tests using a course-keeping model ship with an autopilot system were carried out in a towing tank for research on Safe-Return-to-Port (SRTP). The autopilot system controls the rudder angle and propeller revolution rate by a feedback system. The variation of the heading angle of the test model with different control parameters was investigated first, to ensure that the test model had sufficient course-keeping maneuverability in severe wave conditions. The wave conditions and propeller revolution rate were selected based on SRTP regulations. Tests were conducted in wave conditions corresponding to sea states 4 to 6. The six-degrees-of-freedom motion response of the test model was measured by a wireless inertial measurement unit and gyro sensors to achieve fully wireless model tests. The advance speed and motion response in various wave conditions were measured and analyzed to investigate the effects of flooding behavior in a damaged condition and of waves on the propulsion and maneuvering performance of the damaged ship model.

scholarly journals Augmenting Maneuverability of UUVs with Cycloidal Propellers

2020 ◽  
Author(s):  
Manavendra Desai ◽  
Ruddhi Gokhale ◽  
Atanu Halder ◽  
Moble Benedict ◽  
Yin Lu Young
Keyword(s):  
Degrees Of Freedom ◽  
Underwater Vehicle ◽  
Underwater Vehicles ◽  
Low Speed ◽  
Six Degrees Of Freedom ◽  
Hydrodynamic Motion ◽  
Screw Propeller ◽  
Heave Motion ◽  
Novel Concept ◽  
And Control

This paper investigates the novel concept of augmenting the maneuverability of underwater vehicles with cycloidal propellers. Cycloidal propellers have the potential of providing agile manoeuvring capabilities to an underwater vehicle such as enabling pure heave motion and spot turns. They will also enable the vehicle to surge in forward and backward directions with equal ease. Such manoeuvres are not possible with the more conventional screw propeller and control fin combinations. Moreover, cycloidal propellers can enable precise dynamic positioning in low speed applications like station-keeping, underwater surveying and maintenance, minesweeping and teaming activities. In this paper, manoeuvring capabilities of an underwater vehicle with conventional screw propeller and control fins only are compared with one augmented with cycloidal propellers. The cases considered include a turning circle manoeuvre, a low speed 180o turn and a low speed heave manoeuvre. A six degrees-of-freedom non-linear hydrodynamic motion prediction model was developed and validated. Simulation results demonstrated that compared to conventional propulsion systems, cycloidal propeller augmented underwater vehicles can be more swift and compact in low speed manoeuvres, making a case for further investigation into this concept.

scholarly journals Contact Force Control of Three-Dimensional Flexible Manipulator

2020 ◽  
Author(s):  
Minoru Sasaki ◽  
Shunta Ito ◽  
Daiki Maeno ◽  
Waweru Njeri ◽  
Muguro Josephh ◽  
...  
Keyword(s):  
Contact Force ◽  
Force Control ◽  
Degrees Of Freedom ◽  
Force Feedback ◽  
Three Dimensional ◽  
Flexible Manipulator ◽  
Force Tracking ◽  
Feedback Method ◽  
Three Degrees Of Freedom ◽  
Contact Force Control

This paper proposes a contact force controller for a constrained flexible manipulator in three-dimensional motion. This controller used the conversion formula obtained empirically and experimental results showed the effectiveness of the proposed contact force controller. First, the manipulator was operated with the tip of the second link restrained, then, time response of the root strain, joint angles and contact force were used to derive the relational between the three quantities. The effectiveness of the relational expression was verified by conducting a target contact force tracking experiment by inputting the angle from the relational expression. The contact force control using the strain feedback method was proposed with the strain amount estimated from the target contact force as the target value, and its effectiveness was verified by experiments. From the results obtained, controller using the strain feedback method was designed for the purpose of controlling the contact force at the tip of a flexible manipulator with two links and three degrees of freedom that performs three-dimensional spatial motion, and its effectiveness was shown by comparison with the contact force feedback method.

Development of a Haptic Device with Wire-Driven Parallel Structure

2017 ◽  
Vol 11 (3) ◽  
pp. 385-395
Author(s):  
Carlo Ferraresi ◽  
◽  
Carlo De Benedictis ◽  
Francesco Pescarmona
Keyword(s):  
Degrees Of Freedom ◽  
Force Feedback ◽  
Parallel Structure ◽  
Control Logic ◽  
End Effector ◽  
Six Degrees Of Freedom ◽  
Force Closure ◽  
Force Reflection ◽  
Definition Of ◽  
Selection Of

This study focuses on the specific problems that may arise in the development of a parallel, cable-driven device designed for teleoperations systems utilizing force-reflection feedback. A redundant six degrees-of-freedom structure, actuated by nine wires, is described as a convenient layout for a haptic master for telemanipulation. A methodology for the kinematic and static analysis and the evaluation of the device workspace is described. The condition of force closure is used to find all available poses of the end-effector, thereby defining the workspace, whose characteristics are assessed by opportunely conceived indexes. Typical characteristics of cable and implementations thereof in the device are considered. Regarding the realization of the device, relevant attention is given to the definition of the control logic, which can be complex for parallel devices. The selection of the actuators, crucial in realizing force feedback, is discussed. In particular, pneumatic actuation is considered, verified as the most appropriate method for implementation and force control of the cylinders.

Use of 1DOF Haptic Device for Remote-Controlled 6DOF Assembly

2014 ◽  
Vol 8 (3) ◽  
pp. 452-459 ◽  
Author(s):  
Ryoya Kamata ◽  
◽  
Ryosuke Tamura ◽  
Satoshi Niitsu ◽  
Hiroshi Kawaharada ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Force Feedback ◽  
Haptic Device ◽  
Prototype System ◽  
Assembly Operation ◽  
Six Degrees Of Freedom ◽  
Controlled Assembly ◽  
Sense Of Reality ◽  
Position And Orientation ◽  
Assembly Operations

This paper describes a remote controlled assembly using a haptic device. Most haptic devices have six Degrees Of Freedom (DOFs) for a higher sense of reality. However, for assembly operation, the simultaneous motion of parts with only one or two DOFs is required, and force feedback to operators is used only to maintain contact and detect collisions among parts. This leads to the possibility of assembly operations using a haptic device with a small number of DOFs. In this paper, we propose virtual planes to perform remote control of a 6DOF assembly by way of 1DOF user operations. Virtual planes separate the DOFs for user operation and for automatically generated motions that complement the user operation DOF in each assembly operation. A prototype system was developed with a 6DOF manipulator and camera. The system allows an operator to place virtual planes in any position and orientation using a camera image of the workspace. The experiment results showed the effectiveness of the method for remote controlled assembly without geometry information on the parts.

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