CN-122018384-A - Track control method and system for brushless push rod

CN122018384ACN 122018384 ACN122018384 ACN 122018384ACN-122018384-A

Abstract

The invention relates to the technical field of mechanical control, in particular to a track control method and system of a brushless push rod, wherein the method comprises the steps of generating a reference motion track of the brushless push rod based on a load dynamics model of the brushless push rod; the method comprises the steps of calculating a critical speed threshold corresponding to a current load working condition according to motor current and external load force, comparing a reference speed curve with the critical speed threshold, triggering a track adjustment condition when the reference speed reaches a preset proportion of the critical speed, establishing dynamic speed constraint by associating the critical speed threshold with the reference speed curve after the track adjustment condition is triggered, and carrying out attenuation reconstruction on a reference movement track based on the dynamic speed constraint to obtain a final track control strategy. The invention effectively solves the problems of impact and unsafe caused by the fact that the existing brushless push rod still moves according to a fixed track when the load changes, and improves the stability and operation safety of push rod control.

Inventors

LI RANG
WANG CHENGZHOU

Assignees

南通市久正人体工学股份有限公司

Dates

Publication Date: 20260512
Application Date: 20251205

Claims (10)

1. A method for controlling the trajectory of a brushless putter, the method comprising: generating a reference motion track of the brushless push rod based on a load dynamics model of the brushless push rod, wherein the reference motion track comprises a reference speed curve and a reference acceleration curve; calculating a critical speed threshold corresponding to the current load working condition according to the motor current and the external load force; Comparing the reference speed curve with the critical speed threshold, and triggering a track adjustment condition when the reference speed reaches the preset proportion of the critical speed; After the track adjustment condition is triggered, a dynamic speed constraint is established by associating the critical speed threshold with a reference speed curve, and the reference motion track is attenuated and reconstructed based on the dynamic speed constraint, so that a final track control strategy is obtained.
2. The method according to claim 1, wherein the trajectory adjustment condition further comprises triggering the trajectory adjustment condition when the predicted displacement of the reference motion trajectory is about to enter a safety boundary, the safety boundary being determined based on a remaining distance between a current position of the plunger and a stroke limit.
3. The method according to claim 1, wherein calculating a critical speed threshold corresponding to a current load condition according to a motor current and an external load force, comprises: calculating the instantaneous output thrust of the brushless push rod according to the motor current detection value; Based on the external load force, determining the equivalent load of the push rod under the current working condition; And establishing a mechanical balance relation between the instantaneous output thrust and the equivalent load, and calculating the maximum allowable speed of the push rod under the current working condition, wherein the maximum allowable speed is the critical speed threshold.
4. The method of claim 1, wherein associating the critical speed threshold with a reference speed profile establishes a dynamic speed constraint, comprising: updating the critical speed threshold in real time according to the real-time working condition information of the brushless push rod; The updated critical speed threshold value is used as a speed upper limit and is compared with the reference speed curve time by time to obtain a dynamic speed limit curve based on a time sequence; When the reference speed curve exceeds the corresponding speed value of the dynamic speed limit curve at any moment, taking the corresponding speed value as the target speed at the moment; And constructing a target speed curve based on the target speed corresponding to each moment, and taking the target speed curve as the dynamic speed constraint.
5. The method for controlling the trajectory of a brushless putter as claimed in claim 1, wherein the attenuation reconstruction comprises: Performing amplitude limiting processing on the reference speed curve to obtain an amplitude limiting speed sequence; and constructing a target acceleration sequence based on the limiting speed sequence, and carrying out constraint smoothing on the limiting speed sequence and the target acceleration sequence under the dynamic speed constraint action.
6. The trajectory control method of a brushless putter according to claim 5, wherein the clipping process is performed based on an S-shaped trajectory planning function or an exponential decay function.
7. The method according to claim 1, further comprising determining a trajectory interval in which attenuation is required based on the dynamic speed constraint, the trajectory interval being obtained by identifying a period of time in the reference speed profile exceeding the dynamic speed constraint, before the attenuation is reconstructed.
8. The method of claim 1, wherein after the attenuation reconstruction is completed, comprising: identifying the connection boundary between the attenuated track and the unattenuated track; continuously checking the speed and the acceleration at the connecting boundary; when the discontinuity of the speed or the acceleration is detected, carrying out local smoothing correction on a plurality of track points at the connecting boundary; and generating a reconstruction track meeting the speed continuity and the acceleration continuity according to the correction result.
9. A brushless putter trajectory control system, the system comprising: The reference track generation module is used for generating a reference motion track of the brushless push rod based on a load dynamics model of the brushless push rod, wherein the reference motion track comprises a reference speed curve and a reference acceleration curve; the speed threshold calculating module is used for calculating a critical speed threshold corresponding to the current load working condition according to the motor current and the external load force; the track adjustment triggering module is used for comparing the reference speed curve with the critical speed threshold value, and triggering a track adjustment condition when the reference speed reaches the preset proportion of the critical speed; And the control strategy generation module is used for establishing dynamic speed constraint by associating the critical speed threshold with a reference speed curve after triggering the track adjustment condition, and carrying out attenuation reconstruction on the reference movement track based on the dynamic speed constraint to obtain a final track control strategy.
10. The brushless putter trajectory control system of claim 9, wherein the speed threshold calculation module includes: An instantaneous thrust calculating unit for calculating instantaneous output thrust of the brushless push rod according to the motor current detection value; the equivalent load determining unit is used for determining the equivalent load of the push rod under the current working condition based on the external load force; and the maximum speed calculation unit is used for establishing a mechanical balance relation between the instantaneous output thrust and the equivalent load, and calculating the maximum allowable speed of the push rod under the current working condition, wherein the maximum allowable speed is the critical speed threshold.

Description

Track control method and system for brushless push rod Technical Field The invention relates to the technical field of mechanical control, in particular to a track control method and system of a brushless push rod. Background The brushless push rod is used as a linear driving device commonly used for household adjusting equipment, a brushless direct current motor is generally used as a power source, linear telescopic motion is realized through a transmission mechanism, and along with the continuous improvement of the requirements of application scenes on motion stability, accuracy and safety, the brushless push rod faces a plurality of technical challenges in the motion control process. The existing brushless push rod control method generally adopts a preset speed track or a fixed acceleration model to drive the push rod to move, however, in the actual running process, the external load born by the push rod can change along with the use working condition, and the fixed track cannot reflect the influence of the current load on the allowable movement speed of the push rod. Because the control system cannot dynamically adjust the speed track according to the real-time load, the push rod still moves according to the fixed track when the load is increased, and the problems of overhigh instantaneous speed, insufficient driving force or mechanical impact when the driving force is close to the travel limit are possibly caused, and the problems directly affect the running stability and the mechanism safety of the push rod. Disclosure of Invention The invention provides a track control method of a brushless push rod, which can effectively solve the problems in the background technology. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: A method of trajectory control of a brushless pushrod, the method comprising: generating a reference motion track of the brushless push rod based on a load dynamics model of the brushless push rod, wherein the reference motion track comprises a reference speed curve and a reference acceleration curve; calculating a critical speed threshold corresponding to the current load working condition according to the motor current and the external load force; Comparing the reference speed curve with the critical speed threshold, and triggering a track adjustment condition when the reference speed reaches the preset proportion of the critical speed; After the track adjustment condition is triggered, a dynamic speed constraint is established by associating the critical speed threshold with a reference speed curve, and the reference motion track is attenuated and reconstructed based on the dynamic speed constraint, so that a final track control strategy is obtained. Further, the track adjustment condition further comprises triggering the track adjustment condition when the predicted displacement of the reference motion track is about to enter a safety boundary, wherein the safety boundary is determined according to the residual distance between the current position of the push rod and the travel limit. Further, calculating a critical speed threshold corresponding to the current load working condition according to the motor current and the external load force, including: calculating the instantaneous output thrust of the brushless push rod according to the motor current detection value; Based on the external load force, determining the equivalent load of the push rod under the current working condition; And establishing a mechanical balance relation between the instantaneous output thrust and the equivalent load, and calculating the maximum allowable speed of the push rod under the current working condition, wherein the maximum allowable speed is the critical speed threshold. Further, associating the critical speed threshold with a reference speed profile establishes a dynamic speed constraint comprising: updating the critical speed threshold in real time according to the real-time working condition information of the brushless push rod; The updated critical speed threshold value is used as a speed upper limit and is compared with the reference speed curve time by time to obtain a dynamic speed limit curve based on a time sequence; When the reference speed curve exceeds the corresponding speed value of the dynamic speed limit curve at any moment, taking the corresponding speed value as the target speed at the moment; And constructing a target speed curve based on the target speed corresponding to each moment, and taking the target speed curve as the dynamic speed constraint. Further, the attenuation reconstruction includes: Performing amplitude limiting processing on the reference speed curve to obtain an amplitude limiting speed sequence; and constructing a target acceleration sequence based on the limiting speed sequence, and carrying out constraint smoothing on the limiting speed sequence and the target acceleration sequence under the dynamic spee