Tracking Control of a Software Cam Machining System

1999 ◽  
Vol 121 (4) ◽  
pp. 729-735 ◽  
Author(s):  
Mi-Ching Tsai ◽  
Yaw-Hwei Lee
Keyword(s):  
Control System ◽  
Angular Velocity ◽  
Velocity Profile ◽  
Tracking Control ◽  
Contact Point ◽  
Tangential Velocity ◽  
Position Tracking ◽  
Servo Motor ◽  
Cam Profile ◽  
Angular Velocity Profile

This paper presents a software cam manufacturing system. It includes a position tracking control system, a programmable cam profile, and a programmable variable angular velocity profile. The position tracking system consists of a rotary direct drive (DD) servo motor and a linear servo-motor. The rotary DD servo-motor is controlled to track the variable angular velocity profile, while the linear servo-motor is controlled to synchronously track the desired cam profile. Such a tracking control system is proposed to achieve a constant removal rate for fine machining (i.e., the relative tangential velocity at the contact point should be constant). A numerical method for off-line derivation of the variable angular velocity profile with respect to the desired cam profile is developed to achieve constant relative tangential velocity at the contact point. An experimental tracking control system with two servo controllers is developed to study the feasibility of this approach.

scholarly journals Determining the Tangential Velocity profile of a Rotating Fluid in a Static Container using Navier–Stokes equations

2020 ◽  
Author(s):  
RAJDEEP TAH ◽  
SARBAJIT MAZUMDAR ◽  
Krishna Kant Parida
Keyword(s):  
Angular Velocity ◽  
Velocity Profile ◽  
Velocity Gradient ◽  
Stokes Equations ◽  
Tangential Velocity ◽  
Navier Stokes ◽  
Rotating Fluid ◽  
Navier Stokes Equations ◽  
Similar Principle ◽  
Tangential Velocity Profile

The shape of the liquid surface for a fluid present in a uniformly rotating cylinder is generally determined by making a Tangential velocity gradient along the radius of the rotating cylindrical container. A very similar principle can be applied if the direction of the produced velocity gradient is reversed, for which the source of rotation will be present at the central axis of the cylindrical vessel in which the liquid is present. Now if the described system is completely closed, the angular velocity will decrease as a function of time. But when the surface of the rotating fluid is kept free, then the Tangential velocity profile would be similar to that of the Taylor-Couette Flow, with a modification that; due to formation of a curvature at the surface, the Navier-Stokes law is to be modified. Now the final equation may not seem to have a proper general solution, but can be approximated to certain solvable expressions for specific cases of angular velocity.

Velocity Control of a Cylindrical Rolling Robot by Surface-Morphing

2015 ◽  
Author(s):  
Michael Puopolo ◽  
J. D. Jacob
Keyword(s):  
Mathematical Model ◽  
Angular Velocity ◽  
Velocity Profile ◽  
Average Velocity ◽  
Equations Of Motion ◽  
Angular Position ◽  
Velocity Control ◽  
Control Scheme ◽  
Rolling Robot ◽  
Angular Velocity Profile

A mathematical model is developed for a rolling robot with a cylindrically-shaped, elliptical outer surface that has the ability to alter its shape as it rolls, resulting in a torque imbalance that accelerates or decelerates the robot. A control scheme is implemented, whereby angular position and angular velocity are used as feedback to trigger and define morphing actuation. The goal of the control is to direct the robot to follow a given angular velocity profile. Equations of motion for the rolling robot are formulated and solved numerically. Results show that by automatically morphing its shape in a periodic fashion, the rolling robot is able to start from rest, achieve constant average velocity and slow itself in order to follow a desired velocity profile with significant accuracy.

Self-sensing feedback control of multiple interacting shape memory alloy actuators in a 3D steerable active needle

2020 ◽  
Vol 31 (12) ◽  
pp. 1524-1540
Author(s):  
Saeed Karimi ◽  
Bardia Konh
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Electrical Resistance ◽  
Tracking Control ◽  
Surgical Instruments ◽  
Position Tracking ◽  
Position Tracking Control ◽  
Targeting Accuracy

Percutaneous needle-based intervention is a technique used in minimally invasive surgical procedures such as brachytherapy, thermal ablation, and biopsy. Targeting accuracy in these procedures is a defining factor for success. Active needle steering introduces the potential to increase the targeting accuracy in such procedures to improve the clinical outcome. In this work, a novel 3D steerable active flexible needle with shape memory alloy actuators was developed. Active needle actuation response to a variety of actuation scenarios was analyzed to develop a kinematic model. Shape memory alloy actuators were characterized in terms of their actuation strain, electrical resistance, and required electrical power to design a self-sensing electrical resistance feedback control system for position tracking control of the active needle. The control system performance was initially tested in position tracking control of a single shape memory alloy actuator and then was implemented on multiple interacting shape memory alloy actuators to manipulate the 3D steerable active needle along a reference path. The electrical resistance feedback control of the multiple interacting shape memory alloy actuators enabled the active needle to reach target points in a planar workspace of about 20 mm. Results demonstrated shape memory alloys as promising alternatives for traditional actuators used in surgical instruments with enhanced design, characterization, and control capabilities.

Effect of Inner and Outer Wheels Driving Force Control on Small Electric Vehicle

2020 ◽  
Vol 17 (4) ◽  
pp. 8246-8254
Author(s):  
K. Shibazaki ◽  
H. Nozaki
Keyword(s):  
Control System ◽  
Angular Velocity ◽  
Electric Vehicle ◽  
Force Constant ◽  
Force Control ◽  
Driving Force ◽  
Vehicle Control ◽  
Steering Angle ◽  
Force Control System ◽  
The Difference

In this study, in order to improve steering stability during turning, we devised an inner and outer wheel driving force control system that is based on the steering angle and steering angular velocity, and verified its effectiveness via running tests. In the driving force control system based on steering angle, the inner wheel driving force is weakened in proportion to the steering angle during a turn, and the difference in driving force is applied to the inner and outer wheels by strengthening the outer wheel driving force. In the driving force control (based on steering angular velocity), the value obtained by multiplying the driving force constant and the steering angular velocity,  that differentiates the driver steering input during turning output as the driving force of the inner and outer wheels. By controlling the driving force of the inner and outer wheels, it reduces the maximum steering angle by 40 deg and it became possible to improve the cornering marginal performance and improve the steering stability at the J-turn. In the pylon slalom it reduces the maximum steering angle by 45 deg and it became possible to improve the responsiveness of the vehicle. Control by steering angle is effective during steady turning, while control by steering angular velocity is effective during sharp turning. The inner and outer wheel driving force control are expected to further improve steering stability.

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