Saturday, December 7, 2019
Electro Mechanical Control Systems Engineering Problems
Questions: Part 1 Research, describe and explain in your own words the advantages of using a Top Down approach to engineering problems.Part 2An alternative to fluid based linear actuators is the ball screw linear actuator.Describe in your own words (with diagrams if needed) the following:2.1 Typical construction of a ball screw linear actuator together with an explanation of how it works.2.2 A methodology for speed and position control of a ball screw linear actuator.2.3 Analyse and discuss the relative merits of the ball screw linear actuator when compared to pneumatic and hydraulic cylinders.Part 3 Explain in your own words (with diagrams if needed) why it isimportant for a designer of a PLC programme to understand the use of registers for inputs, outputs and internal programme components. Answer: 1. Advantages of top down approach of engineering problems: - A top-down come within reach is effectively the infringement down of a classification to increase impending into its compositional sub-systems. In a top-down come near an impression of the system is formulated, specifying but not detailing any first-level subsystems. Each subsystem is subsequently superior in yet superior feature, from time to time in a lot of added subsystem levels, until the whole requirement is abridged to foundation rudiments. A top-down replica is frequently particular with the support of "black boxes", these compose it easier to influence. Nevertheless, black boxes possibly will fail to clarify straightforward mechanisms or be comprehensive enough to sensibly authenticate the model. Top down approach starts with the big picture. It breaks losing starting there into smaller segments. Your association realizes a paying attention use of possessions from the entity managed relevance. The first accomplishment becomes a display case for the distinctiveness administration explanation. When the phases are accomplished for the managed submission, you have implemented a deeper, more mature execution of the distinctiveness supervision explanation. Procedure and preservation possessions are not originally impacted as strictly as with the bottom-up approach. Near to the ground friction in ball screws yields high involuntary competence compared to alternatives. A distinctive ball screw may be 85 percent proficient, versus 45 percent efficiency of an Acme lead screw of equal size. Lack of sliding friction flanked by the nut and screw lends itself to extended lifespan of the screw congregation reducing downtime for preservation and parts surrogate, while also lessening insist for lubrication. This collective with their taken as a whole performance remuneration and condensed authority necessities, may counteract the initial expenditure by means of ball screws. 2. [2.1] Image: construction of ball screw actuator A linear actuator using standard motors will commonly have the motor as a separate cylinder attached to the side of the actuator, either parallel with the actuator or perpendicular to the actuator. The motor may be attached to the end of the actuator. The drive motor is of typical construction with a solid drive shaft that is geared to the drive nut or drive screw of the actuator. The inner diameter of the motor shaft can be enlarged, so that the drive shaft can be hollow. The drive screw and nut can therefore occupy the center of the motor, with no need for additional gearing between the motor and the drive screw. Similarly the motor can be made to have a very small outside diameter, but instead the pole faces are stretched lengthwise so the motor can still have very high torque while fitting in a small diameter space. Working: - A linear actuator is an actuator that creates motion in a straight line, in contrast to the circular motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer peripherals such as disk drives and printers, in valves and dampers, and in many other places where linear motion is required. Hydraulic or pneumatic cylinders inherently produce linear motion. Many other mechanisms are used to generate linear motion from a rotating motor. Linear actuator has two basic type of construction one is standard construction and the other is compact construction. [2.2] The position and speed can be controlled by using mechanisms like- Position Control - A type of control system designed for moving objects or machines to a known position. For example: stepper motors are used for position control. Speed Control- speed is often the restrictive feature in selecting a ball screw for a specified application. Like any long, cylindrical entity, a ball screw will unsurprisingly sag in the center due to its own weight. When the screw turns, it begins to whip, or bend, similar to a jump rope. The speed at which the screw starts to come across twisting vibrations is recognized as its critical speed. The speed can be controlled by [ 2.3 ] the ball screw linear actuator has two main merits as compared to the hydraulic and pneumatic cylinders these merits are- Every type of linear actuator is made in a different way and has its own reward. Mechanical linear actuators, for example, are comparatively low-cost, reusable, and self-contained. Piezoelectric linear actuators can generate extremely small linear motions and can therefore be used for microcomputer and micro-mechanical applications. Hydraulic linear actuators can fabricate a large quantity of pressure; consequently they can be used for grave duty applications. Pneumatic linear actuators are less powerful, compact, heavy weight, useful for simple paths only, and provide repeatable motion. The problems raised during the working of a PLC can be easily recognized and troubleshooting by the use of resistors. Some other significance of these resistors are- These functions typically are used to monitor and control entity machines or complex processes via inputs and outputs (I/Os). I/O modules connected to the PLC provide analog or digital electronic interfaces to the external world. The PLC reads inputs, processes them through a program, and generates outputs. One reason for the attractiveness of PLCs is their high dependability in harsh industrial environments; occasionally, however, things do go wrong and troubleshooting becomes necessary. Those unusual with PLCs often fear troubleshooting a device that appears to be a inexplicable "black box" but in fact today's PLCs in fact are very open systems that lend themselves to comparatively easy analysis. The interior operation of a PLC can be monitored via a handheld programmer, terminal, or personal computer, and many indicator lights are provided for I/O troubleshooting. References: 1. GORDON, D. Precision control of high speed drives using active vibration dampingIn-text: (Gordon) Bibliography: Gordon, Daniel. Precision Control Of High Speed Drives Using Active Vibration Damping. Waterloo, Ont.: University of Waterloo, 2010. Print.2. HOSSEINKHANI, Y. Control Methods for Improving Tracking Accuracy and Disturbance Rejection in Ball Screw Feed Drives In-text: (Hosseinkhani)Bibliography: Hosseinkhani, Yasin. Control Methods For Improving Tracking Accuracy And Disturbance Rejection In Ball Screw Feed Drives. Print.3. OUTLAW, C. Actuator Mechanical Devices in Electrical Engineering In-text: (Outlaw) Bibliography: Outlaw, Camron. Actuator Mechanical Devices In Electrical Engineering. New Delhi: World Technologies, 2012. Print.4. ONG, S. K., NEE, A. Y. C. AND XU, Q. L. Design reuse in product development modeling, analysis and optimization In-text: (Ong, Nee and Xu)Bibliography: Ong, S. K, A. Y. C Nee, and Q. L Xu. Design Reuse In Product Development Modeling, Analysi s And Optimization. Hackensack, NJ: World Scientific, 2008. Print.5. ROBERGE, P. R. Handbook of corrosion engineeringIn-text: (Roberge) Bibliography: Roberge, Pierre R. Handbook Of Corrosion Engineering. McGraw-Hill: New York, 2012. Print.6. ONG, S. K., NEE, A. Y. C. AND XU, Q. L. Design reuse in product development modeling, analysis and optimization In-text: (Ong, Nee and Xu)Bibliography: Ong, S. K, A. Y. C Nee, and Q. L Xu. Design Reuse In Product Development Modeling, Analysis And Optimization. Hackensack, NJ: World Scientific, 2008. Print.7. FUJITA, H. AND JOHANNESSON, P. New trends in software methodologies, tools and techniques In-text: (Fujita and Johannesson) Bibliography: Fujita, Hamido, and Paul Johannesson. New Trends In Software Methodologies, Tools And Techniques. Amsterdam: IOS Press/Ohmsha, 2002. Print.8. A SLAKSEN, E. The system concept and its application to engineeringIn-text: (Aslaksen) Bibliography: Aslaksen, E. The System Concept And Its Application To Engineer ing. Berlin: Springer, 2013. Print.9. WERNOW, J. N. On the Future of Head-Based Microactuators in Hard Disk Drives In-text: (Wernow) Bibliography: Wernow, Josiah Natan. On The Future Of Head-Based Microactuators In Hard Disk Drives. Berkeley, CA: N.p., 2012. Print.10. ANTONIADIAS, H. Bibliography: Antoniadias, Hamido, and Paul Johannesson. New Trends In Software Methodologies, Tools And Techniques. Amsterdam: IOS Press/Ohmsha, 2002. Print.
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