Autoleveller in Drawframe

Auto leveling is a technology used in various industries and applications to maintain a consistent level or height of a surface or object. It uses sensors and control systems to adjust the position or height of the object automatically, without the need for manual intervention.

While there may be different names used by different manufacturers for auto leveling technology, the fundamental principle and functionality are typically the same. Other common terms used to refer to auto leveling technology include automatic leveling, self-leveling, and automatic height control. These terms all describe the ability of a system to maintain a specified level or height automatically.

 Auto Levelling is done in two ways.

  1. Open Loop.
  2. Close Loop.

Open Loop: When action and sensor sense the feed count on the feed material to change the draft is know as an open loop.


Close Loop: Sensor sense the delivery count and send this sense to feed in this process and draft is changed accordingly is known as close loop.

i) Open loop Autoleveller:
The open loop control principle, which can be used for the correction of fairly short term variations, where the solid lines indicate the flow of fibers through the m/c & the broken lines represent to flow of information in the autoleveller unit. The control unit compares the measurement signal with the reference signal which in this case represents the mean output reqd. The control unit accordingly increases, leaves unaltered, or decreases the output of the regulatory which in turn provides a variable speed to the back of front rollers of the process to give the required draft when the measured material  has reached the point at which draft is applied. The magnitude & direction of each change in draft is determined by the magnitude of the change of count previously indicated by the measuring unit. Most of the drawframe autoleveller are open loop auto levellers.

Fig (a): Schematic diagram of open loop control system

If the direction of the arrows in (a) is followed from any starting point, it always leads out into the open from the diagram at the place marked material by the control unit. Measurement always takes place on the material prior to the material. Thus if measurement is made on the input material, the correction may be applied to either the back rollers or the front rollers.

ii) Closed loop Autoleveller:
The closed loop principle is illustrated in (b); this system is used for the correction of long-term & medium-term variations. Again the measurement signal is compared with the reference signal by the control unit which then determines the output of the regulator which provides the variable speed to the process to give the required draft.

Fig (b): Schematic diagram of closed

However, if the direction of the arrows in (b), is following from any starting point except the delivery, is always leads to a never-ending circuit of the loop which links the process & the control unit together, hence the name closed loop; measurement always takes place on the mtl after the point where corrective action is applied. Thus if measurement is made on the output, the correction may be applied to either the back rollers or the front rollers.

It is immediately apparent that the control unit continually cheeks the results of its own actions because measurement is taken from the product of the process. This may be regarded as a basic advantage of the closed loop system, but it is obtained at the price of increased complexity.

Advantages of Autolevelling:

Autoleveling technology offers several advantages in various applications. Some of these advantages include:

1. Increased accuracy: Autoleveling systems use sensors and control systems that can make precise adjustments to maintain a specific level or height, resulting in greater accuracy than manual adjustments.

2. Improved efficiency: Autoleveling systems can operate continuously without the need for manual adjustments, allowing for increased productivity and reduced downtime.

3. Consistency: Autoleveling systems can maintain a consistent level or height, regardless of changes in the environment or variations in the material being processed. This can help ensure consistent quality and reduce waste.

4. Safety: Autoleveling systems can improve safety by reducing the need for manual adjustments, which can be dangerous in certain environments.

5. Cost-effective: While autoleveling systems may require an initial investment, they can ultimately be more cost-effective than manual adjustments over the long term, due to increased efficiency, productivity, and accuracy.


Leave a Reply

Your email address will not be published. Required fields are marked *