6.7 Servo axis - eliminating steady-state errors

In systems where precise positioning accuracy is required, it is often necessary to position within one encoder count. Proportional gain, KPROP, is not normally able to achieve this because a very small following error will only produce a small demand for the drive which may not be enough to overcome mechanical friction (this is particularly true in current controlled systems). This error can be overcome by applying integral gain. The integral gain, KINT, works by accumulating following error over time to produce a demand sufficient to move the motor into the required position with zero following error.

KINT can therefore overcome errors caused by gravitational effects such as vertically moving linear axes. With current controlled drives a non-zero demand output is required to hold the load in the correct position, to achieve zero following error.

Care is required when setting KINT since a high value will cause instability during moves.

A typical value for KINT would be 0.1. The effect of KINT should also be limited by setting the integration limit, KINTLIMIT, to the smallest possible value that is sufficient to overcome friction or static loads, for example 5. This will limit the contribution of the integral term to 5% of the full demand output range.

1.Click in the KINT box and enter a small starting value, for example 0.1.

2.Click in the KINTLIMIT box and enter a value of 5.

With NextMove ES, the action of KINT and KINTLIMIT can be set to operate in various modes:

HNever - the KINT term is never applied

HAlways - the KINT term is always applied

HSmart - the KINT term is only applied when the demand speed is zero or constant.

HSteady State - the KINT term is only applied when the demand speed is zero.

This function can be selected using the KINTMODE drop down box.

MN1928

Operation 6-21

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Baldor MN1928 installation manual Servo axis eliminating steady-state errors
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MN1928 specifications

The Baldor MN1928 is a highly regarded motor designed for a variety of industrial applications, known for its durability and efficiency. This motor is part of Baldor’s extensive range of products, which are engineered to meet the demands of heavy-duty operations.

One of the key features of the Baldor MN1928 is its robust construction. Built with high-quality materials, this motor is designed to withstand harsh environmental conditions often found in industrial settings. The steel frame is not only resilient, but it also enhances the motor's cooling capabilities, enabling it to perform effectively over extended periods.

The MN1928 is equipped with advanced technologies that optimize its performance. One notable technology is the use of high-efficiency induction motor design. This reduces energy consumption significantly and contributes to lower operational costs. The motor is also designed with a continuous duty rating, making it capable of running for long hours without compromising its functionality or lifespan.

In terms of characteristics, the Baldor MN1928 features a reliable ball bearing design, which minimizes friction and wear, ensuring smoother operation and increased reliability. With a horsepower rating that suits a range of applications, it provides the necessary torque and speed to power various machinery effectively. The multi-voltage design allows for versatile installation options, accommodating different electrical systems while ensuring efficient performance.

Another important characteristic of this motor is its ease of maintenance. The design allows for straightforward access to components, making it simple for technicians to perform routine checks and maintenance. This is particularly beneficial in industrial settings where downtime can be costly.

Safety is also a priority in the design of the Baldor MN1928. Equipped with thermal overload protection, it prevents overheating, reducing the risk of damage caused by excessive temperatures during operation. Additionally, the motor complies with various industry standards, ensuring safe operation within diverse environments.

In summary, the Baldor MN1928 stands out as a reliable choice for industrial applications, offering a combination of durability, efficiency, and advanced technology. Its robust construction, high-efficiency design, and safety features make it a preferred option for many enterprises seeking dependable motor solutions.
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