Typically the position or velocity of machines are controlled using some type of device such as a hydraulic pump, linear actuator, or electric motor, generally a servo. Motion control is an important part of robotics and CNCmachine tools, however in these instances it is more complex than when used with specialized machines, where the kinematics are usually simpler. The latter is often called General Motion Control (GMC). Motion control is widely used in the packaging, printing, textile, semiconductor production, and assembly industries. Motion Control encompasses every technology related to the movement of objects. It covers every motion system from micro-sized systems such as silicon-type micro induction actuators to micro-siml systems such as a space platform. But, these days, the focus of motion control is the special control technology of motion systems with electric actuators such as dc/ac servo motors. Control of robotic manipulators is also included in the field of motion control because most of robotic manipulators are driven by electrical servo motors and the key objective is the control of motion.[2]
Overview
The basic architecture of a motion control system contains:
A motion controller, which calculates and controls the mechanical trajectories (motion profile) an actuator must follow (i.e., motion planning) and, in closed loop systems, employs feedback to make control corrections and thus implement closed-loop control.
A drive or amplifier to transform the control signal from the motion controller into energy that is presented to the actuator. Newer "intelligent" drives can close the position and velocity loops internally, resulting in much more accurate control.
A prime mover or actuator such as a hydraulic pump, pneumatic cylinder, linear actuator, or electric motor for output motion.
In closed loop systems, one or more feedback sensors such as absolute and incremental encoders, resolvers or Hall effect devices to return the position or velocity of the actuator to the motion controller in order to close the position or velocity control loops.
Mechanical components to transform the motion of the actuator into the desired motion, including: gears, shafting, ball screw, belts, linkages, and linear and rotational bearings.
The interface between the motion controller and drives it control is very critical when coordinated motion is required, as it must provide tight synchronization. Historically the only open interface was an analog signal, until open interfaces were developed that satisfied the requirements of coordinated motion control, the first being SERCOS in 1991 which is now enhanced to SERCOS III. Later interfaces capable of motion control include Ethernet/IP, Profinet IRT, Ethernet Powerlink, and EtherCAT.
Common control functions include:
Velocity control.
Position (point-to-point) control: There are several methods for computing a motion trajectory. These are often based on the velocity profiles of a move such as a triangular profile, trapezoidal profile, or an S-curve profile.
Impedance control: This type of control is suitable for environment interaction and object manipulation, such as in robotics.
Electronic gearing (or cam profiling): The position of a slave axis is mathematically linked to the position of a master axis. A good example of this would be in a system where two rotating drums turn at a given ratio to each other. A more advanced case of electronic gearing is electronic camming. With electronic camming, a slave axis follows a profile that is a function of the master position. This profile need not be salted, but it must be an animated function
Tan K. K., T. H. Lee and S. Huang, Precision motion control: Design and implementation, 2nd ed., London, Springer, 2008.
Ellis, George, Control System Design Guide, Fourth Edition: Using Your Computer to Understand and Diagnose Feedback Controllers
References
↑Ma, Jun; Li, Xiaocong; Tan, Kok Kiong (2020). "1.1: Overview of Motion Control Systems". Advanced Optimization for Motion Control Systems. United States: CRC Press, Taylor & Francis Group. p.1. ISBN978-1000037111., Google Books Retrieved April 30, 2020.
↑原島 文雄 (1996). 「メカトロニクスの最近の進歩」. IEEE 国際産業エレクトロニクスシンポジウム論文集. 第1 巻. pp. 1–4 . doi : 10.1109/ISIE.1996.548386 . ISBN0-7803-3334-9. S2CID 108759313 .
