Tapered Roller Speed Control for Uniform Ring Rolling
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Solution Overview
Problem
Existing axial radial rolling mills face challenges in maintaining uniform ring growth and preventing shape defects due to inadequate dynamic response of speed controllers for tapered rollers, especially as ring dimensions vary.
Innovation Solution
A method of controlling the axial radial rolling mill by adjusting the rotational speed of tapered rollers using a feedback contribution from PI or PID controllers, with coefficients of the proportional and integrative parts varied based on physical parameters of the ring being processed, such as weight and diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the rotational speed of tapered rollers is adjusted using fixed PI or PID controller coefficients calibrated for nominal conditions, then the control system is simple and easy to implement, but the dynamic response becomes inadequate when ring parameters vary, resulting in non-uniform ring growth and shape defects
Solution Approach 1:
The patent applies the dynamics principle by transitioning from fixed controller coefficients to variable coefficients that adapt in real-time based on actual ring parameters (weight, dimensions). The controller dynamically adjusts the rotational speed of tapered rollers according to the current state of the ring being processed, enabling the system to maintain optimal performance across varying operating conditions rather than relying on pre-calibrated nominal values
Solution Approach 2:
The patent implements parameter changes by modifying the controller coefficients (Kp, Ki, Kd) based on measured ring parameters such as weight and dimensions. The system continuously updates these control parameters to match the actual ring being processed, allowing the controller to adapt its behavior to different ring sizes, weights, and geometries, thereby preventing shape defects and ensuring uniform growth
2Manufacturing precision
If the vertices of tapered rollers are kept aligned with the centre of the ring, then the peripheral speeds can be equalised at all contact points, but this becomes impossible when the ring diameter increases beyond certain limits
Solution Approach 1:
The patent applies feedback by using sensors to measure the actual position and parameters of the ring being processed, then feeding this information back to the controller. The controller uses this feedback to calculate the appropriate rotational speed corrections for the tapered rollers, ensuring that peripheral speeds are equalised at all contact points even when the ring diameter is large and vertex alignment with the ring centre is no longer geometrically possible
Solution Approach 2:
The system changes the rotational speed parameter of the tapered rollers based on measured ring parameters. When the ring diameter increases beyond the limit where vertex alignment is possible, the controller adjusts the rotational speed to compensate for the geometric mismatch, maintaining peripheral speed equalisation through parameter adaptation rather than geometric alignment
3Stability of the object's composition
If fixed controller coefficients are used calibrated for nominal conditions, then the control system remains stable under predefined conditions, but the dynamic response becomes excessively slow or oscillatory when processing rings with different characteristics
Solution Approach 1:
The patent implements parameter changes by continuously adjusting the controller coefficients (Kp, Ki, Kd) based on the actual ring parameters being processed. When processing rings with different characteristics (weight, dimensions, geometry), the system modifies these parameters to optimize the dynamic response, preventing excessive slowness or oscillatory behavior that would occur with fixed coefficients calibrated only for nominal conditions
Data Source
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AI summary
A method for controlling an axial radial rolling mill (100) for rings (200), wherein the axial radial rolling mill (100) comprises: a main roller (105), a contrast roller (110), a pair of guide rollers (115), and a pair of tapered rollers (130, 135); wherein the control method provides for adjusting the rotational speed of each tapered roller (130, 135) by means of the steps of: establishing a reference value (v) of the rotational speed of the tapered roller (130, 135), applying a correction (d1, d2) to said reference value (v) to obtain a corrected value (v*, v**) of the rotational speed of the tapered roller (130, 135), actuating the tapered roller (130, 135) at a rotational speed having the corrected value (v*, v**); the correction (d1, d2) comprising at least one feedback contribution (r1, r2) provided by a controller (S120, S150) of the proportional-integrative or proportional-integrative-derivative type; the control method providing for varying at least the coefficients of the proportional part and of the integrative part of the controller (S120, S150) on the basis of the value of at least one physical parameter of the ring (200) being processed. The invention also relates to an axial radial rolling mill for rings.