CN-122018329-A - Visual guide track deviation correction system based on dynamic tracking

CN122018329ACN 122018329 ACN122018329 ACN 122018329ACN-122018329-A

Abstract

The invention relates to the technical field of industrial automation and machine vision control, in particular to a vision guiding track deviation correction system based on dynamic tracking, which comprises a state buffer module, a state buffer module and a control module, wherein the state buffer module is used for acquiring the position of a real-time encoder, a real-time planning reference position and a system clock at a preset sampling rate and writing the position and the real-time planning reference position and the system clock into a state annular buffer area; the system comprises a visual resolving module, a state backtracking module, an error generating module, a feedforward compensation module and a current control loop, wherein the visual resolving module acquires exposure instant image data and a latched global clock time stamp and resolves a target state quantity, the state backtracking module extracts a historical encoder position and a historical planning reference position according to the time stamp, the error generating module verifies the target state quantity based on the historical planning reference position and generates an absolute visual error, and the feedforward compensation module generates an error compensation transition curve and is overlapped to a bottom control instruction of the current control loop. The invention converts the problem of visual large time delay into the problem of alignment of historical states, realizes stable correction of real track deviation and reduces the influence of time-varying delay on control stability.

Inventors

LI GUIDONG
LI DAWEI
XU JIANHUA
ZHANG TAO
ZHOU ENZE

Assignees

南京耘瞳科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (10)

1. The utility model provides a vision guide track deviation correction system based on dynamic tracking, its control system who is applied to communication connection and has controlled actuating mechanism and vision sensor which characterized in that includes: The state buffer module is used for collecting the real-time encoder position, the real-time planning reference position and the system clock of the controlled executing mechanism at a preset sampling rate, and continuously pressing the real-time encoder position, the real-time planning reference position and the system clock into a state annular buffer area; The visual resolving module is used for acquiring image data generated by the visual sensor at the moment of exposure and a latched global clock time stamp, and resolving a target state quantity of the controlled executing mechanism with the global clock time stamp based on the image data; The state backtracking module is used for responding to the output of the target state quantity by the visual resolving module, searching and extracting the historical encoder position and the historical planning reference position corresponding to the global clock time stamp of the controlled executing mechanism in the state annular buffer area according to the global clock time stamp; the error generation module is used for verifying the validity of the target state quantity based on the historical planning reference position, and performing difference processing on the target state quantity and the historical encoder position after verification is passed so as to generate an absolute visual error; And the feedforward compensation module is used for generating an error compensation transition curve based on the absolute visual error and superposing the error compensation transition curve to a bottom control instruction of a current control loop of the controlled executing mechanism in combination with a preset outer ring visual compensation gain.
2. The system for correcting deviation of visual guide track based on dynamic tracking according to claim 1, wherein the state buffer module is specifically configured to: according to a preset clock period, packaging the real-time encoder position, the real-time planning reference position and the corresponding system clock into a state data frame; And writing the state data frame into the state annular buffer area opened up in the preset bottom random access memory according to the first-in first-out principle.
3. The dynamic tracking-based visual guide trajectory deviation correction system of claim 1, wherein the means for the visual solution module to obtain the global clock time stamp comprises: Synchronizing and aligning a trigger clock of the vision sensor with the system clock through a preset accurate time protocol; at the physical moment that the vision sensor executes image exposure, latching the current system clock by a preset hardware trigger as the global clock time stamp; binding the global clock timestamp with the image data.
4. The dynamic tracking based visual guide trajectory deviation correction system of claim 1, wherein said state backtracking module extracts said historical encoder positions comprising: judging whether the global clock time stamp is exactly matched with the system clock recorded in the state ring buffer; If the global clock time stamp is accurately matched with the system clock recorded in the state ring buffer, directly extracting the corresponding real-time encoder position as the historical encoder position; If the global clock time stamp is not matched with the system clock recorded in the state annular buffer area, searching a first system clock and a second system clock which are respectively earlier and later than the global clock time stamp in time in the state annular buffer area; extracting a first encoder position corresponding to the first system clock and a second encoder position corresponding to the second system clock; And calculating the historical encoder position corresponding to the global clock timestamp by adopting a linear interpolation algorithm and combining the first encoder position and the second encoder position.
5. The dynamic tracking-based visual guide trajectory deviation correction system of claim 1, wherein said error generation module generates said absolute visual error by: Calculating the space position deviation between the target state quantity and the historical planning reference position to obtain a state deviation degree; judging whether the state deviation degree is larger than a preset error threshold value or not; If the state deviation is smaller than or equal to the preset error threshold, judging that verification is passed, and performing difference processing on the target state quantity and the historical encoder position to generate the absolute visual error; if the state deviation degree is larger than the preset error threshold value, judging that verification is not passed, discarding the target state quantity and outputting a boundary crossing alarm signal.
6. The dynamic tracking based visual guide trajectory deviation correction system of claim 1, wherein the feed forward compensation module comprises: The curve generation unit is used for generating the error compensation transition curve based on a smooth curve through a preset kinematic forward model by taking the absolute visual error as a state variable; the instruction superposition unit is used for extracting the compensation increment corresponding to the error compensation transition curve in a preset continuous clock period; And combining the outer loop visual compensation gain, and adding the compensation increment to the bottom layer control instruction cycle by cycle.
7. The dynamic tracking-based visual guide trajectory deviation correction system of claim 6, wherein said error compensation transition curve is a smooth curve; The tangent direction of the starting point of the smooth curve is consistent with the current movement direction of the controlled executing mechanism; the end point of the smooth curve converges to a fully compensated state of the absolute visual error.
8. The dynamic tracking-based visual guidance trajectory deviation correction system of claim 1, further comprising: The gain adjusting module is used for acquiring the updating frequency of the absolute visual error and judging whether the updating frequency is higher than a preset frequency threshold value or not; if the update frequency is higher than the preset frequency threshold value, setting the outer ring visual compensation gain to a preset high gain value; if the update frequency is equal to the preset frequency threshold value, maintaining the current outer ring visual compensation gain; and if the updating frequency is lower than the preset frequency threshold value, reducing the outer ring visual compensation gain to a preset low gain value.
9. The dynamic tracking-based visual guide track deviation correction system of claim 1, wherein the controlled actuator is a universal motion platform; The control architecture of the system is divided into an instruction scheduling layer, a visual processing layer and a servo execution layer; The visual processing layer operates on a preset independent computing node, and the servo execution layer and the state annular buffer zone operate on a preset bottom layer motion controller.
10. The system for dynamically tracking-based visual guidance track deviation correction of claim 1, wherein the controlled actuator performs a state correction action in physical space upon receiving the underlying control command overlaying the error compensation transition curve; The vision sensor continuously captures the corrected physical space state and generates a new target state quantity to form a non-synchronous and multi-sampling rate closed-loop control data stream.

Description

Visual guide track deviation correction system based on dynamic tracking Technical Field The invention relates to the technical field of industrial automation and machine vision control, in particular to a vision guiding track deviation correction system based on dynamic tracking. Background In the existing vision guiding motion control system, the control system generally comprises a controlled executing mechanism and a vision sensor, wherein the controlled executing mechanism continuously moves according to a preset track, the vision sensor collects target marks, edge contours or process characteristics in the moving process, and the recognition result is used for track deviation correction. However, a certain time is usually consumed from exposure, image transmission to image calculation by the vision sensor, so that a vision processing result corresponds to a space state at a certain moment in the past, and in the prior art, the vision result is often directly compared or compensated with the position of an actuating mechanism at the current moment, so that the normal displacement of the actuating mechanism during time delay is easily misjudged as track deviation, and the problems of time dislocation compensation, jitter correction and control stability reduction are caused. In addition, when the existing scheme is used for compensation, consistency backtracking of a historical state and validity verification of the visual result are often lacking, when reflection, shielding, misrecognition or data updating instability exists in an image, an incorrect target state quantity is easily directly sent into a control loop, and further compensation mutation and poor track continuity are caused, so that correction precision and operation stability in a dynamic tracking process are difficult to achieve. Disclosure of Invention The invention aims to provide a visual guide track deviation correction system based on dynamic tracking, which solves the following technical problems: track dislocation and abnormal oscillation caused by direct use of an observation result with large visual time delay are avoided, and space-time decoupling of the servo execution internal state and visual external measurement is easier to realize, so that smooth and stable correction of the true track deviation is completed. The aim of the invention can be achieved by the following technical scheme: The utility model provides a vision guide track deviation correction system based on dynamic tracking, its is applied to the control system that communication connection has controlled actuating mechanism and vision sensor, includes: The state buffer module is used for collecting the real-time encoder position, the real-time planning reference position and the system clock of the controlled executing mechanism at a preset sampling rate, and continuously pressing the real-time encoder position, the real-time planning reference position and the system clock into a state annular buffer area; The visual resolving module is used for acquiring image data generated by the visual sensor at the moment of exposure and a latched global clock time stamp, and resolving a target state quantity of the controlled executing mechanism with the global clock time stamp based on the image data; The state backtracking module is used for responding to the output of the target state quantity by the visual resolving module, searching and extracting the historical encoder position and the historical planning reference position corresponding to the global clock time stamp of the controlled executing mechanism in the state annular buffer area according to the global clock time stamp; the error generation module is used for verifying the validity of the target state quantity based on the historical planning reference position, and performing difference processing on the target state quantity and the historical encoder position after verification is passed so as to generate an absolute visual error; And the feedforward compensation module is used for generating an error compensation transition curve based on the absolute visual error and superposing the error compensation transition curve to a bottom control instruction of a current control loop of the controlled executing mechanism in combination with a preset outer ring visual compensation gain. Optionally, the state caching module is specifically configured to: according to a preset clock period, packaging the real-time encoder position, the real-time planning reference position and the corresponding system clock into a state data frame; And writing the state data frame into the state annular buffer area opened up in the preset bottom random access memory according to the first-in first-out principle. Optionally, the means for obtaining the global clock timestamp by the visual resolving module includes: Synchronizing and aligning a trigger clock of the vision sensor with the system clock through a preset accurate time p