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CN-121984405-A - Linear transmission precise positioning method of ball spline

CN121984405ACN 121984405 ACN121984405 ACN 121984405ACN-121984405-A

Abstract

The invention relates to a linear transmission precise positioning method of a ball spline, which belongs to the technical field of information and comprises the steps of obtaining a matching range of geometric parameters of a ball spline shaft and a stator of a linear motor, determining geometric constraint conditions of a coaxial sleeve type nested structure, collecting axial temperature data of the ball spline shaft for temperature field change after heat transfer, determining an axial thermal deformation compensation amount, calculating according to the axial thermal deformation compensation amount and a motor rotor position feedback value, determining a target correction position of linear motion to obtain a thermal compensation position instruction, driving the motor rotor to move through the thermal compensation position instruction, collecting actual position feedback to obtain real-time position deviation, and carrying out radial thermal deformation monitoring on the real-time position deviation, determining a radial compensation vector and superposing the radial compensation vector to the position instruction to obtain a final positioning position of comprehensive thermal deformation.

Inventors

  • WU PENG

Assignees

  • 东莞市汉艺精密机械有限公司

Dates

Publication Date
20260505
Application Date
20260202

Claims (9)

  1. 1. A linear transmission precise positioning method of a ball spline is characterized by comprising the steps of obtaining a matching range of geometric parameters of a ball spline shaft and a linear motor stator, determining a coaxial sleeve type nested structural geometric constraint condition, fixedly connecting a motor rotor and the ball spline shaft in a direct driving mode by adopting a permanent magnet linear synchronous motor according to the structural geometric constraint condition to obtain an integrated direct driving transmission assembly, filling a radial gap between the linear motor stator and the ball spline shaft with a heat conduction material to realize heat directional conduction, obtaining a physical channel for uniform heat transmission, collecting axial temperature data of the ball spline shaft according to temperature field change after heat transmission, determining an axial thermal deformation compensation amount, calculating according to the axial thermal deformation compensation amount and a motor rotor position feedback value, determining a target correction position of linear motion, obtaining a thermal compensation position instruction, driving the motor rotor to move through the thermal compensation position instruction, obtaining real-time position deviation, carrying out radial monitoring on the real-time position deviation, determining a radial compensation vector and obtaining a final positioning position instruction of comprehensive thermal deformation, repeatedly executing position closed loop control and full-stroke combined thermal deformation, and realizing high-rigidity positioning of the ball spline in a full-stroke composite motion.
  2. 2. A linear transmission precise positioning method of a ball spline is characterized by comprising the steps of obtaining a matching range of geometric parameters of a ball spline shaft and a linear motor stator, determining geometric constraints of a coaxial sleeve type nesting structure, obtaining outer diameter size parameters and length parameters of the ball spline shaft, extracting outer diameter values from the outer diameter size parameters, inputting the outer diameter values through a pre-established motor magnetic field distribution model, outputting corresponding magnetic field uniform sections, calculating an inner diameter matching range of the linear motor stator to obtain an inner diameter lower limit value and an inner diameter upper limit value, determining a gap threshold value of the coaxial sleeve type nesting structure according to the inner diameter matching range in combination with material thermal expansion compensation, obtaining nesting gap parameters, adjusting the length parameters if the nesting gap parameters exceed the preset threshold value, recalculating the geometric constraints of the coaxial sleeve type nesting structure by subtracting compensation offset to obtain adjusted constraint conditions, judging feasibility of the coaxial sleeve type nesting structure from the adjusted constraint conditions, and determining final geometric constraints of the coaxial sleeve type nesting structure.
  3. 3. A linear transmission precise positioning method of a ball spline is characterized in that a permanent magnet linear synchronous motor is adopted to fixedly connect a motor rotor with a ball spline shaft in a direct driving mode according to structural geometric constraint conditions to obtain an integrated direct driving transmission assembly, the method comprises the steps of obtaining stress distribution characteristics under different working conditions through structural adaptation analysis of connection positions of the motor rotor and the ball spline shaft, determining connection point distribution schemes required by fixedly connecting stability according to the stress distribution characteristics to obtain preliminary fixedly connected design parameters, adjusting the shape and the size of the connection positions according to the preliminary fixedly connected design parameters and combining geometric constraint conditions to obtain an optimized connection structure layout, judging whether the optimized connection structure layout meets assembly precision requirements to obtain an adapted connection scheme, analyzing a power transmission path to obtain vibration noise distribution data through simulating working condition environments to determine a noise control key area to obtain noise suppression measures, and combining heat emission management requirements to adjust material distribution and ventilation paths of the key area to determine a final integrated direct driving transmission assembly structure.
  4. 4. A linear transmission precise positioning method of a ball spline according to claim 1 is characterized in that radial gaps between a linear motor stator and a ball spline shaft are filled with heat conducting materials to achieve directional heat conduction, a physical channel for unified heat transfer is obtained, the method comprises the steps of obtaining temperature distribution data of contact surfaces of the linear motor stator winding and the ball spline shaft through an infrared thermal imager, analyzing thermal gradient differences according to the temperature distribution data, determining heat non-uniform areas in the radial gaps in combination with gap geometric characteristics to obtain a gap filling priority scheme, filling the radial gaps with materials with high heat conductivity coefficients according to the gap filling priority scheme to obtain uniform distribution of the heat conducting materials, judging a post-filling heat resistance reduction degree through a heat resistance test to obtain a preliminary directional conduction structure, obtaining heat transfer efficiency data through simulating a heat flow path under dynamic load, adjusting material layer thickness to optimize axial heat balance, determining a stable channel, verifying heat transfer continuity through the stable channel, and integrating transmission thermal stability indexes to obtain final physical channel configuration.
  5. 5. A linear transmission precise positioning method of a ball spline according to claim 1 is characterized by comprising the steps of collecting axial temperature data of a ball spline shaft according to temperature field changes after heat transfer, determining an axial thermal deformation compensation amount, collecting values of an axial multipoint temperature sensor of the ball spline shaft according to the temperature field changes, obtaining real-time temperature distribution data, recording temperature difference changes through monitoring point placement to obtain an axial temperature sequence, inquiring a pre-calculated thermal expansion coefficient mapping table according to the axial temperature sequence, determining a corresponding coefficient at the current temperature, obtaining an axial elongation increment according to a preset temperature interval matching elongation rule, integrating thermal deformation related stress distribution evaluation, simulating a deformation path, obtaining a preliminary thermal deformation value according to axial stress displacement change deduction, adjusting component clearance parameters according to the preliminary thermal deformation value, and determining a final axial thermal deformation compensation amount according to axial thermal non-distribution characteristics.
  6. 6. A linear transmission precise positioning method of a ball spline according to claim 1 is characterized in that the linear transmission precise positioning method is characterized in that a target correction position of linear motion is determined according to an axial thermal deformation compensation amount and a motor rotor position feedback value to obtain a thermal compensation position command, the method comprises the steps of obtaining an axial temperature sequence of a ball spline shaft through temperature field monitoring, determining a current thermal expansion increment by combining elongation amount calculation attributes to obtain an axial elongation amount, recording the motor rotor position feedback for the axial elongation amount through real-time data acquisition, integrating displacement change simulation deduction deformation distribution to obtain a preliminary compensation value, processing fusion stress distribution evaluation according to the preliminary compensation value through superposition operation, adjusting a clearance parameter to calibrate a heating characteristic to obtain an axial deformation compensation amount, obtaining the motor rotor position feedback superposition content from the axial deformation compensation amount, judging a target position correction path, and determining a final thermal compensation position command.
  7. 7. A linear transmission precise positioning method of a ball spline is characterized by comprising the steps of driving a motor rotor to move through a thermal compensation position command, collecting actual position feedback to obtain real-time position deviation, driving the motor rotor to move through a servo driving input fusion position closed-loop control algorithm through the thermal compensation position command to obtain actual position data, obtaining encoder feedback collection content aiming at the actual position data, determining a deviation value through feedback and command difference operation, judging a command correction fusion path from the deviation value, adjusting feedback circulation parameters to obtain a motion precision monitoring result, and obtaining response time calibration by adopting a system response optimization processing deviation threshold judgment according to the motion precision monitoring result to determine final real-time position deviation.
  8. 8. A linear transmission precise positioning method of a ball spline according to claim 1 is characterized in that radial thermal deformation monitoring is conducted on real-time position deviation, a radial compensation vector is determined and superimposed on a position command to obtain a final positioning position of comprehensive thermal deformation, the method comprises the steps of starting a radial thermal deformation monitoring module to acquire multi-position sensor data of the outer diameter of a stator of a linear motor to obtain a real-time displacement value according to the condition that the real-time position deviation exceeds a preset threshold, judging the radial expansion degree through the multi-position sensor data, calculating the coaxiality deviation according to a preset corresponding mode of the outer diameter change of the stator and the axial position relation to obtain the coaxiality deviation value, determining the amplitude and the direction of the radial compensation vector according to the coaxiality deviation value, obtaining the compensation vector through calculation of the deviation and the compensation coefficient, superimposing the radial compensation vector on an original position command to obtain a comprehensive position command after fusion thermal compensation, and driving a motor rotor to move to complete the final positioning position.
  9. 9. A linear transmission precise positioning method of a ball spline is characterized in that the linear transmission precise positioning method repeatedly executes a position closed-loop control and thermal deformation compensation process to achieve high-rigidity linear motion and rotary positioning combined action of the ball spline shaft in a full stroke, and comprises the steps of obtaining real-time temperature field data and position feedback signals of the ball spline shaft, judging heat source distribution through the temperature field data, determining initial deviation values through the position feedback signals, conducting heat source partition regulation according to the temperature field data, calculating deviation integral and differential terms through a control algorithm, obtaining compensation parameters through proportional integral differential combination, adjusting the length of a transmission chain and the thermal deformation quantity through the compensation parameters to obtain uniform heat management balanced distribution, inputting the compensation parameters into a closed-loop control circuit, conducting linear motion and rotary positioning synchronous correction on the ball spline shaft to obtain a combined action primary coupling result, repeatedly executing the full stroke on the primary coupling result, returning heat source partition regulation compensation parameters if errors exceed a preset threshold until errors converge, and determining a final combined action result.

Description

Linear transmission precise positioning method of ball spline Technical Field The invention relates to the technical field of information, in particular to a linear transmission precise positioning method of a ball spline. Background In the field of high-precision automation equipment, particularly in the scenes of semiconductor manufacture, precise optical instrument assembly, high-end robot joint transmission and the like, the transmission component which can provide large-stroke linear motion and simultaneously has a high-precision rotation positioning function is realized, and the transmission component has extremely critical significance. The compound motion requirement directly determines whether the whole machine can achieve higher machining precision, faster response speed and more stable running state. The proposal commonly adopted in the industry at present is to take a ball spline as a guiding and driving element, and realize the movement by an additional linear motor or a combination of a rotating motor and a ball screw. Although the split type arrangement can be marginally satisfactory in function, the whole transmission chain is obviously lengthened due to the fact that power is transmitted between the motor and the spline by means of a coupling, a synchronous belt or an intermediate connecting piece such as a screw nut. The extension of the power transmission path causes a large amount of gaps, elastic deformation and additional rotational inertia to be accumulated in the system, and after the factors are overlapped, the dynamic response speed of the system is severely limited, and particularly in the high-speed precise movement occasions needing quick start and stop and frequent reversing, the residual vibration is difficult to quickly attenuate, and the positioning time is obviously prolonged. The problem of the deeper layer is that the heat generated by the motor and the heat generated by friction during the operation of the spline pair are in a separated state, and the temperature rise rule and the thermal expansion direction of the motor and the spline pair are often inconsistent. The temperature rise of the motor stator mainly causes radial dimension change, and the axial thermal expansion of the spline shaft directly affects the linear positioning precision. This mismatch in thermal deformations can deviate both axially and radially after a continuous run of the apparatus for a period of time, eventually leading to reduced accuracy in repeated positioning and even workpiece rejection in some extreme processes. Therefore, the method thoroughly eliminates the response delay and vibration amplification effect brought by the intermediate transmission link while maintaining the original high rigidity, large load capacity and long stroke characteristics of the ball spline, and realizes the unified management of the heat quantity of the motor and the thermal expansion of the spline, so that the thermal deformation of the motor and the thermal expansion of the spline can be cooperatively controlled, and the method becomes a core difficult problem faced by the current high-precision compound motion transmission technology. Disclosure of Invention The invention provides a linear transmission precise positioning method of a ball spline, which mainly comprises the following steps: The method comprises the steps of obtaining a matching range of geometric parameters of a ball spline shaft and a linear motor stator, determining a coaxial sleeve type nested structure geometric constraint condition, fixedly connecting a motor rotor and the ball spline shaft in a direct driving mode by adopting a permanent magnet linear synchronous motor according to the structure geometric constraint condition to obtain an integrated direct driving transmission component, filling a radial gap between the linear motor stator and the ball spline shaft by a heat conduction material to realize heat directional conduction, obtaining a physical channel for uniform heat transfer, collecting axial temperature data of the ball spline shaft aiming at temperature field change after heat transfer, determining an axial thermal deformation compensation quantity, calculating according to the axial thermal deformation compensation quantity and a motor rotor position feedback value, determining a target correction position of linear motion to obtain a thermal compensation position command, driving the motor rotor to move by the thermal compensation position command, collecting actual position feedback to obtain a real-time position deviation, monitoring radial thermal deformation according to the real-time position deviation, determining a radial compensation vector and superposing to the position command to obtain a comprehensive final positioning position, and repeatedly executing a position closed-loop control and thermal deformation compensation process to realize high-rigidity linear motion and thermal deformation positioning of t