Measuring Calculation of Handheld Laser Range Finder
First, the measurement and calculation of the laser rangefinder.
The hand-held laser range finder is a semiconductor laser range finder that integrates optomechanical and electrical, and is characterized by natural surface reflection measurement to accurately measure short distances in space. At present, it is widely used in construction, equipment, real estate, surveying and mapping and other fields. The steel ruler has many advantages in measurement, saves manpower and material resources, and improves operating efficiency.
1. Verification requirements for handheld laser rangefinders.
According to the requirements of the JJG966-2001 Handheld Laser Rangefinder Verification Regulations, the instrument in use is roughly as follows:
(1) The influence of ranging when the voltage changes;
(2) The commonality of the reflector and the measured value;
(3) The influence of temperature changes on ranging;
(4) Measurement repeatability;
(5) increase constant;
(6) General judgment of ranging standard error.
Second, detection.
1. Measurement repeatability.
Choose a suitable orientation to arrange the handheld laser rangefinder and reflector, and measure the distance continuously 10 times at one time according to the policy, and calculate the repeatability of the measurement.
2. Adding constants and the accuracy of adding constants and summarizing judgment policies.
Use the 20-meter indium steel ruler as the baseline of the inspection channel, arrange the instrument at one end of the baseline, and adjust the rangefinder to align with the reflector so that the measurement axis is parallel to the baseline axis, and then move the reflector in order from near to far Observation values (10 segments) are obtained by measurement, and the average value of 5 readings for each observation is taken as the observation value.
At present, in laser ranging, there are three main time distance measurement methods commonly used: pure counting method, quasi-interpolation, and digital interpolation.
The pure counting circuit is simple, the measurement range is long, but the accuracy is low, and it is generally not selected separately; the imitation interpolation method can improve the counting accuracy to the ps level, but because it is based on the charge and discharge technology of the capacitor, the linearity is poor, the measurement time is long, and it is affected. The interference of temperature and electromagnetic radiation is large, which is not suitable for the high real-time and harsh working environment of the ranging sensor system; the digital interpolation method is based on the delay line insertion technology, and the single pulse measurement accuracy is high, the measurement plan is large, and the measurement can be repeated, which is very suitable for Laser distance sensor.
