Motion controller

Abstract: The trade-off between the noise-sensitivity and the performance of disturbance estimation is well-known in the Disturbance Observer- (DOb-) based motion control systems As the bandwidth of the DOb increases, not only the performance but also the frequency range of disturbance estimation improves yet the motion controller becomes more sensitive to the noise of measurement system This trade-off is generally explained by considering only the noise of sensors such as encoders However, the digital implementation of the robust motion controller may significantly influence the noise sensitivity and performance of disturbance estimation in practice This paper shows that the conventional DOb implemented by estimating velocity is subject to waterbed effect when the design parameters (ie, sampling-time, nominal plant parameters and the bandwidth of the DOb) are not properly tuned in the digital motion controller synthesis Therefore, the bandwidth of disturbance estimation is limited by waterbed effect in addition to the noise of velocity measurement system To facilitate the digital motion controller synthesis, the design constraints of the conventional DOb are analytically derived in this paper When the digital motion controller is implemented by estimating acceleration, waterbed effect does not occur, and good robust stability and performance can be achieved for all values of the design parameters of the acceleration measurement-based DOb The bandwidth of disturbance estimation, however, cannot be freely increased due to the noise of acceleration sensors in practice By employing Bode Integral Theorem in the discrete-time domain, the design constraints of the DOb-based digital motion control systems are clearly explained and it is shown that acceleration measurement can be used to enhance the bandwidth of the DOb, ie, the performance and frequency range of disturbance estimation To verify the proposed analysis and synthesis methods, simulation results are given for the DOb-based position and force control systems

Abstract: In the motion controller, RAM expansion and ROM expansion are connected to DSP controller to complete storing and processing data jointly; TCP/IP is utilized to connect between DSP controller and devices in up layer as well as to carry out protocol process in data link layer; with control data being received from DSP controller, D/A conversion card carries out D/A conversion, then output drive module executes functions of isolation and magnified output to drive servo control unit; double frequency counter reshapes, doubles and counts the position feed back signal received, then outputting result to DSP controller. In the invention, DSP supporting floating-point operation constitutes a push-in type system, DA channel and feedback by high-speed double frequency counter to realize motion control in high speed and high accuracy; general TCP/IP interface realizes open type control and information sharing in the system.

Abstract: An open architecture numerical control of milling machine system based on PC and MPC02 motion control was developedThe system has the function of automatic graphic programming,dynamic tracking for the cutting trace and simulationHardware and software of the system were introduced

Abstract: To satisfy the requirements of motion control for industrial machine, a multi-axis motion controller based on DSP is developed in this paper. The motion controller consists of DSP which plays a main role in this design; DPRAM to make sure the rapid and reliable communication with host; FPGA to handle the task of address decoder and receiving feed-back encoder signal; and several peripheral logic circuits. In the part of hardware design, overall structure of motion control system is presented. Then, the Feed-Forward Proportional-Integral-Velocity (FFPIV) scheme which introduces KV in term of velocity loop to achieve the accurate, smooth and real-time response is proposed in the software developing part. The experiment data are carried out to indicate that this motion controller has advantages of superior performance and highly machining precision.