Use Of Servo Research Articles

Sheet Metal Forming Optimization Methodology for Servo Press Process Control Improvement

In sheet metal forming manufacturing operations the use of servo presses is gaining more interest due to the opportunity to improve process performance (quality, productivity, cost reduction, etc.). It is not yet clear how to proceed in the engineering process when this type of operating machine is used to achieve the maximum possible potential of this technology. Recently, several press builders have developed gap- and straight-sided metal forming presses adopting the mechanical servo-drive technology. The mechanical servo-drive press offers the flexibility of a hydraulic press with the speed, accuracy and reliability of a mechanical press. Servo drive presses give the opportunity to improve the productivity of process conditions and improve the quality of stamped parts. Forming simulation and numerical optimization can be useful tools to define beforehand the optimal process parameter set-up in terms of servo press downward curve properties. This is done by carrying out a sensitivity analysis of the forming parameters having influence on said curve. The authors have developed a numerical methodology able to analyze the influence factors, for comparison with the degrees of freedom made available by the usage of a servo press, in terms of stroke profile management, to obtain an optimized process parameters combination.

A method of manufacturing car mufflers by wrapping sheets, using innovative forming device with the use of servo drive

The paper presents a method of manufacturing a car muffler (tailpipe) of various purpose and shape from deep drawing steel. The shape and size is tailored to the customer’s requirements for visual and mechanical parameters, which significantly limits the production capacity due to the need to create many tools that are time-consuming and expensive to manufacture. Therefore, the authors created their own forming device for wrapping the shape of the tailpipe depending on the geometric requirements, that allows for both a unit and a serial production depending on the requirements.

Design and Development of an Educational 5-DoF Robotic Arm

The effective training of engineering students require hands-on experience in what they would later work with in the industry. The trend in manufacturing nowadays is towards robotics and automation. Relevant to this technology is the robotic hand. This paper outlines the design and the development of a 5-DoF (Degree of Freedom) robotic arm. The robotic arm is intended for educational purposes. The design proposed the use of servos to power the joints and to implement the inverse kinematics of the robotic arm. A simulation of the robotic arm was achieved by using the Matlab Robotics Toolbox, to visualise the joint movements. A suitable servo controller was selected for the implementation and a control software for the robotic arm was developed using Microsoft's C# programming language. The software allows the robotic arm gripper to be postioned in space, by specifying the coordinates of its centre position. Polymethyl methacrylate was selected to fabricate the components of the robotic arm. The robotic arm was tested by specifying various coordinates for the gripper with reference to the robot's base and measuring the corresponding coordinates of the centre position of the gripper, which gave satisfactory results.

Closed-loop control of eccentric presses based on inverse kinematic models

This work shows how to control the ram motion in servo-mechanical presses with non-linear kinematics by means of a model-based closed-loop control. The use of servo drives in forming machines allows for an arbitrarily controlled drive motion and paves the way for modern, more flexible and adaptable forming machines. However, servo-mechanical presses hardly go beyond the closed-loop control of their servo drives. Especially the control of eccentric presses suffers from non-linear kinematics that impede a closed-loop ram motion control. As a result, the actual position, speed and acceleration of the ram are uncontrollable and harmful effects like tilting occur under real process conditions. We present how to precisely control the ram motion by means of a model-based closed-loop control for a multi-point eccentric press. Using position sensors measuring the ram position in three degrees of freedom and the inverse kinematics of the machine, a closed-loop ram motion control is demonstrated. Experiments investigating different types of control under process conditions show a significant improvement in the accuracy of the ram motion.

Holographic Read-Only-Memory System for High-Speed Replication

A novel high-capacity holographic read-only-memory (ROM) disc system is proposed that stores multiple disc-sized data patterns as multiplexed holograms within a single holographic disc using a conical reference beam for rotational symmetry during recording, with continuous serial readout during playback. Estimates predict user-data capacities of 100 GB or more in a 12 cm disc, with replication speeds of a minute or less, using current holographic media parameters and high-power lasers. A method for fabricating transmissive metallic disc-sized data masks is developed and confirmed experimentally for features down to 0.4 µm, through a variation of the optical disc mastering process. The retrieval of raw holographic eye-patterns at a rotation speed of 1000 rpm without the use of servos is demonstrated for linear densities of 0.67 µm per channel bit with EFMPlus channel coding.

The use of servos in the Army during the past war

The use of servos in the Army during the past war

The use of servos in the Army during the past war

The paper reviews the principal applications of servo mechanisms to Army weapons during the past war, giving in each case a general description of the particular system employed, and outlining the main historical and design factors governing its adoption. Features of design of special interest are noted. It is not claimed that the number of examples given is exhaustive, but it is representative of the field covered in relation to Army weapons.