G(s) = [16 + 0.144s + 1000/s} ∗ 250/ (s+250)

The notch filter has two complex zeros, Z and z, and two complex poles, P and p.

The effect of the notch filter is to cancel the resonance affect by placing the complex zeros on top of the resonance poles. The notch poles, P and p, are programmable and are selected to have sufficient damping. It is best to select the notch parameters by the frequency terms. The poles and zeros have a frequency in Hz, selected by the command NF. The real part of the poles is set by NB and the real part of the zeros is set by NZ.

The most simple procedure for setting the notch filter, identify the resonance frequency and set NF to the same value. Set NB to about one half of NF and set NZ to a low value between zero and 5.

ZOH

The ZOH, or zero-order-hold, represents the effect of the sampling process, where the motor command is updated once per sampling period. The effect of the ZOH can be modeled by the transfer function

H(s) = 1/(1+sT/2)

If the sampling period is T = 0.001, for example, H(s) becomes: H(s) = 2000/(s+2000)

However, in most applications, H(s) may be approximated as one.

This completes the modeling of the system elements. Next, we discuss the system analysis.

System Analysis

To analyze the system, we start with a block diagram model of the system elements. The analysis procedure is illustrated in terms of the following example.

Consider a position control system with the DMC-1700/1800 controller and the following parameters:

Kt = 0.1

J= 2.10-4R = 2

Ka = 4 KP = 12.5 KD = 245 KI = 0 N = 500 T = 1

Nm/A

Torque constant

kg.m2

System moment of inertia

Ω

Motor resistance

Amp/Volt

Current amplifier gain

 

Digital filter gain

 

Digital filter zero

 

No integrator

Counts/rev

Encoder line density

ms

Sample period

The transfer function of the system elements are:

Motor

M(s) = P/I = Kt/Js2 = 500/s2 [rad/A]

Amp

Ka = 4 [Amp/V]

DAC

Kd = 0.0003 [V/count]

DMC-1700/1800

Chapter 10 Theory of Operation • 193

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Galil DMC-1700, DMC-1800 user manual System Analysis, Motor, Amp
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DMC-1800, DMC-1700 specifications

The Galil DMC-1700 and DMC-1800 are advanced motion controllers widely recognized for their high performance and versatility in the automation and robotics industries. These controllers are designed to meet the demands of complex motion control applications, providing users with enhanced features and innovative technologies that optimize motion precision and efficiency.

One of the main features of the Galil DMC-1700 is its ability to handle up to 8 axes of motion control. This capability makes it suitable for a range of applications, from simple point-to-point movements to intricate trajectories in multi-axis systems. In contrast, the DMC-1800 extends this functionality, supporting up to 64 axes, making it ideal for large-scale automation environments.

Both models leverage Galil's powerful programming interface, which simplifies the development of motion control applications. The DMC-1700 and DMC-1800 controllers utilize a high-level programming language that supports advanced motion commands, including linear interpolation, circular interpolation, and complex motion profiles. This feature allows users to implement sophisticated motion sequences seamlessly.

In terms of connectivity, the Galil DMC series offers multiple communication options, including Ethernet, RS-232, and CAN bus, ensuring compatibility with various hardware and enabling easy integration into existing systems. The controllers also come equipped with digital and analog I/O ports, providing flexibility for sensor feedback and actuator control.

The advanced technology incorporated into both the DMC-1700 and DMC-1800 includes on-board PID control, which ensures precise motion control through closed-loop feedback. This results in improved stability and accuracy, particularly in high-speed applications. Additionally, the controllers offer extensive diagnostics and monitoring capabilities, allowing for real-time performance analysis and troubleshooting.

Another notable characteristic of these motion controllers is their compact design, which offers space-saving advantages while maintaining high processing power. Their robust construction and ability to operate in challenging environments make them suitable for a wide range of industrial applications, from CNC machining to assembly lines.

In conclusion, the Galil DMC-1700 and DMC-1800 motion controllers stand out due to their high-performance capabilities, advanced programming features, and flexibility in connectivity. With their ability to handle complex motion control tasks efficiently, these controllers are invaluable tools for engineers and manufacturers looking to enhance their automation processes. By integrating Galil's innovative motion control technology, industries can achieve greater precision, speed, and reliability in their operational workflows.
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