Đang chuẩn bị liên kết để tải về tài liệu:
Mechanical Systems Design Handbook P5

Tham khảo tài liệu 'mechanical systems design handbook p5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 5 Machine Tool Monitoring and Control 5.1 Introduction 5.2 Process Monitoring Tool Wear Estimation Tool Breakage Detection Chatter Detection 5.3 Process Control Kourosh Danai Control for Process Regulation Control for Process University of Massachusetts Optimization Amherst 5.4 Conclusion 5.1 Introduction Machine tool monitoring and control are essential for automated manufacturing. Monitoring is necessary for detection of a process anomaly to prevent machine damage by stopping the process or to remove the anomaly by adjusting the process inputs feeds and speeds . A process anomaly may be gradual such as tool wheel wear may be abrupt such as tool breakage or preventable such as excessive vibration chatter. Knowledge of tool wear is necessary for scheduling tool changes detection of tool breakage is important for saving the workpiece and or the machine and identifying chatter is necessary for triggering corrective action. One difficulty in machine tool monitoring stems from the limited sensing capability afforded by the harsh manufacturing environment. Sensors can seldom be placed at the point of interest and when located at remote locations they do not provide the clarity of measurement necessary for reliable monitoring. This limited sensing capability is often compensated for by using multiple sensors to enhance reliability. Another difficulty in machine tool monitoring is the absence of accurate analytical models to account for changes in the measured variables by variations in the cutting conditions. Such changes are often attributed to process anomalies by the monitoring system which result in false alarms. Machine tool control is motivated by two objectives 1 process regulation so as to preempt excessive forces correct a process anomaly or reduce contouring errors and 2 process optimization for the purpose of improving the quality of the part or reducing operation time based on feedback from the process. The aim of this chapter is to provide a conceptual .