tailieunhanh - BASICS OF INDUSTRIAL SERVO DRIVESC

The control user should be familiar with servos. The user will understand what a servo is and why it is required in so many applications. This discussion will answer these two basic questions: What is a servo? Why use a servo? Any discussion of servos will have to employ the term ‘‘feedback.’’ Thousands of times every day we require information to be ‘‘fed back’’ to us so that we can perform normal activities. When controlling a car down a highway, feedback is provided to our brain by the gift of sight | I BASICS OF INDUSTRIAL SERVO DRIVES Copyright 2003 by Marcel Dekker Inc. All Rights Reserved 1 The What and Why of a Machine Servo The control user should be familiar with servos. The user will understand what a servo is and why it is required in so many applications. This discussion will answer these two basic questions What is a servo Why use a servo Any discussion of servos will have to employ the term feedback. Thousands of times every day we require information to be fed back to us so that we can perform normal activities. When controlling a car down a highway feedback is provided to our brain by the gift of sight. How terrifying it would be if we were traveling at 70 mph and we lost the ability to see. Our brain which is the center of our control system would have little feedback to help it decide what corrective actions need to be taken to maintain a proper path. The poorer feedback channels still available would be the senses of hearing and touch which would allow us to ride the shoulder. The result would be a lower speed poorer control a very irregular path and a greater chance for an accident. Inferior feedback on a machine blinds the operator or the control just as it does a driver. When using numerical control and servos poor feedback can result in inferior parts poor productivity and high costs. Essentially feedback is the retrieval of information about the process being controlled. It verifies that the machine is doing as commanded. There are two types of feedback negative and Copyright 2003 by Marcel Dekker Inc. All Rights Reserved positive. Positive feedback used for instance in radios is not discussed here. Negative feedback required to make a servo work properly subtracts from commands given to the servo so that a discrepancy or error between output and input can be detected. This discrepancy initiates an action that will cause that discrepancy to approach zero. A perfect example of a negative feedback system is a wall thermostat and furnace as .

• Cơ sở dữ liệu
• positioning time
• accuracy
• reliability
• Improved repeatability
• Servo clamping
• Coordinated movements
• Automatic identification system
• Positioning method
• Time of arrival
• Marine vessel positioning based on AIS signals
• Time of arrival estimation method
• Forest inventory
• Global positioning system
• Real time measurements
• Kinematic method
• Differential GPS
• Báo cáo khoa học
• báo cáo y học
• công trình nghiên cứu về y học
• tài liệu về y học
• cách trình bày báo cáo
• BMC Pulmonary Medicine
• Cystic fibrosis
• Body position
• Nebuliser delivery rate
• Confidence interval