CN-121995352-A - Automatic calibration method for pulse width and temperature combination of solid-state laser radar production line

Abstract

Aiming at the defects of the prior art, the invention provides a combined automatic calibration method for pulse width and temperature of a solid-state laser radar production line, which aims to solve the problems of long calibration time, repeated operation and poor compensation consistency of different batches. In the invention, the principle of 'priority pulse width compensation and temperature compensation following' is adopted, in the pulse width compensation process, a dynamic compensation method is adopted, temperature compensation data is collected after single pulse width compensation is finished, temperature compensation calculation is started under the condition that pulse width compensation is finished after single-round temperature circulation, the temperature compensation adopts a linear fitting method, the centroid of an imaging point is calculated, the centroid offset relative to normal temperature at different temperatures is compensated, a temperature compensation parameter file is generated and is applied to a subsequent algorithm, and the pulse width and temperature combined automatic calibration of the solid-state laser radar is realized.

Inventors

• HE GUANGMING
• QIU JIANMING
• Request for anonymity
• GAO MENG

Assignees

• 天目鑫望(苏州)科技有限公司

Dates

Publication Date

20260508

Application Date

20251230

Claims (2)

1. 1. A method for automatically calibrating the pulse width and temperature of solid-state laser radar production line includes such steps as dynamic compensation, collecting the data of temperature compensation after single pulse width compensation, calculating the temperature compensation by linear fitting method, calculating the mass center of imaging point, compensating the mass center offset of different temperatures, generating a temperature compensation parameter file, and applying it to follow-up algorithm to realize the automatic calibration of pulse width and temperature of solid-state laser radar: S1, setting a calibration temperature range and a change step length; s2, collecting and calculating the half-peak width of the laser output at normal temperature; S3, setting the temperature of the incubator; s4, pulse width compensation; S5, temperature compensation data acquisition; S6, temperature compensation calculation.
2. 2. The method for automatically calibrating the pulse width and the temperature of the solid-state laser radar production line in a combined mode according to claim 1, wherein in the step S2, a data acquisition environment is deployed in an incubator at normal temperature, a frame of raw data is acquired, and a half-peak width F is calculated; in the step S3, setting the temperature of the incubator as Tmin, stabilizing after the module, collecting one frame of raw data, calculating the half-peak width F_i, and calculating the I F-F_i I; in the S4, when the frequency of F-F_i is 200ps, carrying out negative compensation on the laser radar, carrying out raw data acquisition again after the compensation, circularly executing S401 until the frequency of F-F_i is 200ps, carrying out pulse width compensation at the temperature, entering S5, carrying out positive compensation on the laser radar when the frequency of F-F_i is 200ps, carrying out pulse width compensation at the temperature after the compensation, entering S5 after the circular execution S401 until the frequency of F-F_i is 200ps, carrying out pulse width compensation at the temperature, entering S5, when the frequency of F-F_i is 200ps, carrying out pulse width compensation at the temperature, entering S5, collecting a frame of raw data as temperature compensation data at the temperature in the S5, returning to S3 after the collection, continuing to execute the temperature stepping once, S4, entering S6 after the temperature is stepped to Tmin, carrying out the temperature polling from Tmin to Tmax, carrying out the calculation of the temperature at the end, carrying out the temperature at the temperature point map, carrying out the calculation, carrying out the linear fitting on the temperature map by the temperature map to the temperature map data at the temperature map 10, carrying out the temperature map data at the temperature map 10, and the temperature map data at the temperature map is different from the temperature map 10, and the centroid is fitted by the same as the temperature map data at the temperature map of the temperature map is obtained by the temperature map data at the temperature map of the temperature map 10x, and finishing the temperature compensation of the laser radar.

Description

Automatic calibration method for pulse width and temperature combination of solid-state laser radar production line Technical Field The invention relates to a laser radar calibration technology, in particular to a solid-state laser radar production line pulse width and temperature combined automatic calibration method. Background Solid state lidars have entered the capacity production phase, pure solid state lidars based on dToF (direct time of flight) typically employ VCSEL arrays as the emission source and SPAD (single photon avalanche diode) arrays as the receivers. The pulse width of the VCSEL can drift along with the change of temperature, current and batch, the drift is converted into trigger time offset after passing through a front edge identification circuit, so that the ranging value of the same target moves back and forth along with the different temperatures or channels to form non-negligible fixed deviation, the deviation can be amplified by targets with different reflectivities, the white wall and the black column are measured to different depths at the same distance, and the multi-channel chip has layered dislocation due to inconsistent pulse width difference and influences the subsequent fusion and positioning. The temperature is the primary external factor of the drift, the vehicle-mounted environment requires the radar to work at the full performance of-40 ℃ to 85 ℃, experiments show that the equivalent pulse width of the VCSEL can be changed by about 0.3 ns only by a single variable of the temperature, the equivalent pulse width corresponds to a 'moving wall' false image of approximately 5 cm, the SPAD breakdown voltage is reduced along with the temperature rise, the discrimination threshold is relatively raised, and the inter-channel dispersion is further amplified. The two temperature coefficients are opposite in direction and different in amplitude, the single-module Quan Wen ranging curve after superposition presents a non-zero slope, and the slopes of all channels are inconsistent, so that the integral offset and internal dislocation of the point cloud are caused. The existing pulse width and temperature compensation method for the solid-state laser radar mostly adopts manual operation and station compensation, and has the defects of inconsistent compensation, repeated work and low automation degree. Therefore, the invention provides a method for automatically calibrating the pulse width and the temperature of a solid-state laser radar production line in a combined way, which compresses the range finding error of the solid-state laser radar to an acceptable range for automatic driving. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a combined automatic calibration method for pulse width and temperature of a solid-state laser radar production line, which aims to solve the problems of long calibration time, repeated operation and poor compensation consistency of different batches. In the invention, the principle of 'priority pulse width compensation and temperature compensation following' is adopted, in the pulse width compensation process, a dynamic compensation method is adopted, temperature compensation data is collected after single pulse width compensation is finished, temperature compensation calculation is started under the condition that pulse width compensation is finished after single-round temperature circulation, the temperature compensation adopts a linear fitting method, the centroid of an imaging point is calculated, the centroid offset relative to normal temperature at different temperatures is compensated, a temperature compensation parameter file is generated and is applied to a subsequent algorithm, and the pulse width and temperature combined automatic calibration of the solid-state laser radar is realized. In order to achieve the above object, the present invention specifically performs the steps of: S1, setting a calibration temperature range and a change step length; s2, collecting and calculating the half-peak width of the laser output at normal temperature; S3, setting the temperature of the incubator; s4, pulse width compensation; S5, temperature compensation data acquisition; S6, temperature compensation calculation. In the step S1, the minimum temperature Tmin and the maximum temperature Tmax of the calibration temperature are set, and the temperature change step length of the incubator is set to be Δt, and then the number of temperature points collected by the single-round temperature cycle is k= (Tmax-Tmin)/Δt. In the step S2, a data acquisition environment is deployed in an incubator at normal temperature, one frame of raw data is acquired, and half-peak width F is calculated. In the step S3, the temperature of the incubator is set to be Tmin, after the module is stabilized, one frame of raw data is collected, the half-peak width F_i is calculated, and the I F-F_i I is calculated. In S4, the pulse width is compensat