CN104748689A - Train catenary height non-contact measuring system based on parallel laser radars - Google Patents

Abstract

The invention discloses a train catenary height non-contact measuring system based on parallel laser radars, relates to the technical field of laser ranging, and solves the problems that existing ultrasonic radar sensors are easily interfered by other sound waves and are slow in response as compared with the laser radars, and the like. The train catenary height non-contact measuring system a laser radar array, a GPS solar altitude positioning module, a data collecting and processing module, a laser radar alignment angle adjusting structure and a catenary height output module. The train catenary height non-contact measuring system has the advantages that multiple levels of laser radars are used to perform equal-interval circulation scanning and measuring in a parallel pipeline manner, self-adaptive fast positioning can be performed on catenaries with different stagger values, and the limitation that a single laser radar is long in measuring cycle can be avoided; in addition, by the GPS solar altitude positioning module, the alignment angle of the laser radar system is adjusted according to the actual operation direction of a train to prevent the laser radar system from being affected by direct strong sunlight.

Description

Non-contact measurement system for train catenary height based on parallel lidar

technical field

The invention relates to the technical field of laser distance measurement, in particular to a fast and high-precision measurement system for the height of railway catenary wires based on parallel laser radar and solar altitude angle inverse tracking technology.

Background technique

When the electric locomotive is running, it obtains continuous electric energy from the catenary through the pantograph at its top. However, during the running of the train, due to the influence of external terrain fluctuations, wiring structure and external environmental factors, the height of the catenary varies to varying degrees, which in turn leads to frequent electric arcs due to the untimely adjustment of the pantograph lap angle. Put some, affect energy efficiency utilization. Therefore, certain technical means must be adopted to quickly predict the current catenary height in a short distance while the train is moving, and provide real-time feedback for the pantograph lap angle. The patent whose publication number is CN202229747U adopts the mode of pull wire sensor to measure the height of catenary. Because this method adopts the indirect measurement of contact height, there are the following problems in the process of use: first, the long-term mechanical contact measurement, the wear and aging of the measuring equipment is relatively serious; second, the indirect measurement often cannot reflect the real height of the catenary The third is that the results of the deformation of the wire sensor can only be used to reverse the measurement results, and it is difficult to achieve a high degree of short-term prediction. Publication number is the patent of CN2300909, adopts ultrasonic radar to carry out catenary height measurement. Although this method uses non-contact measurement, the ultrasonic radar sensor is susceptible to other sound wave interference, and the response is slower compared with the lidar. However, the patent with publication number CN103852011A uses laser radar for measurement, but does not fully consider the influence of other stray lights, especially sunlight, on the measurement results.

Contents of the invention

In order to solve the problems that the ultrasonic radar sensor is easily interfered by other sound waves in the existing catenary wire measurement method, and the measurement results are easily affected by other stray lights when the laser radar is used, the present invention provides a train catenary height based on parallel laser radar Non-contact measuring system.

A non-contact measurement system for train catenary height based on parallel laser radar, the measurement system is fixed at a specified distance in front of the pantograph device on the top of the train; the system includes a laser radar array, a GPS solar altitude angle positioning module, data acquisition and processing module, lidar alignment angle adjustment module and catenary height output module;

The GPS solar altitude positioning module is used to obtain the current position and time information of the train in real time, and calculate the current solar altitude; simultaneously, the solar altitude information is transmitted to the data acquisition and processing module;

The data acquisition and processing module is used to send the sun altitude angle information to the laser radar alignment angle adjustment module; it is also used to send a timing drive signal to the laser radar array to control each laser radar in the laser radar array to cycle at equal intervals Measurement to realize the continuous measurement of the height of the catenary wire, and process the measured catenary height information and send it to the catenary height output module;

The laser radar array, according to the timing drive signal sent by the receiving data acquisition and processing module; performs rapid positioning scanning and height measurement on the current position of the catenary wire; and sequentially transmits the collected scanning data to the data acquisition and processing module;

The laser radar alignment angle adjustment module adjusts the support direction of the mechanical support arm of the laser radar array according to the sun altitude angle information sent by the received data collection and processing module, so as to control the alignment angle of the laser radar array;

The catenary height output module is used to receive the catenary height information of the data acquisition and processing module, and feed back the catenary height information to the pantograph control terminal in real time;

The formula for the height of the catenary from the upper surface of the train is:

H＝Lcosαsinθ+d

In the formula, θ is the angle between the lidar and the upper surface of the train, α is the angle between the catenary scanning position and the position directly in front of the radar scanning; L is the catenary distance measured by the lidar, and d is the distance between the lidar target surface and the upper surface of the train Height correction value, H is the height of the catenary from the upper surface of the train.

Beneficial effects of the present invention: the measurement system described in the present invention improves wire positioning and measurement speed by operating multiple laser radars in parallel in a time-division multiplexing manner; specifically, the following aspects are embodied:

1. The use of non-contact measurement can reduce the complexity of the measurement system and the wear of the measurement sensor; the measurement result is fast and has high measurement accuracy.

2. The direct measurement of catenary height is adopted to avoid measurement errors caused by other factors in the process of other indirect measurement;

3. Using a parallel laser radar array with a variable number of laser radars, the measurement interval can be flexibly modified according to the real-time requirements of specific measurements.

4. Using the solar altitude tracking module, the angle can be adjusted by adjusting the laser radar array to avoid the influence of direct sunlight on the measurement results.

Description of drawings

Fig. 1 is the block diagram of the non-contact measuring system of the train catenary height based on parallel lidar according to the present invention;

Fig. 2 is the schematic diagram of the installation position of the non-contact measuring system for the height of the train catenary based on parallel laser radar according to the present invention;

Fig. 3 is a schematic diagram of laser radar scan profile curves in the non-contact measuring system for the height of train catenary based on parallel laser radar according to the present invention;

Fig. 4 is a schematic diagram of adjusting the alignment angle of the laser radar array with the sun altitude angle in the non-contact measurement system for the height of the catenary catenary based on parallel laser radar according to the present invention.

Detailed ways

Specific Embodiments 1. This embodiment is described in conjunction with FIGS. 1 to 4. The fast and high-precision measurement system for catenary height based on parallel laser radar includes a laser radar array, a GPS solar altitude positioning module, a data acquisition and processing module, and a laser Radar alignment angle adjustment structure and catenary height output module.

The entire measuring device is fixed at a specified distance in front of the pantograph device on the top of the train. The specified distance ranges from 1m to 2m;

The laser radar array is fixed at the end of the laser radar alignment angle adjustment structure on the top of the measuring device, and its scanning field of view is aligned with all possible distribution ranges of catenary zigzag wires at a specified distance in front of it. It is used for fast positioning scanning and height measurement of the current position of catenary conductors. According to the timing driving signal, each lidar in the control array is cyclically measured at equal intervals in turn to shorten the overall single measurement time. Its calculation expression is as follows:

$\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}$

in, is the average scanning measurement time, T is the single scanning measurement time of the laser radar, and N is the number of cascaded laser radars. Taking the measurement system of two lidars as an example, when the measurement interval of a single radar is 30ms, the overall average measurement time is shortened to 15ms.

The GPS solar altitude positioning module calculates the current solar altitude by acquiring the current position and time information of the train in real time.

The data acquisition and processing module adopts the dual processor mode of FPGA+DSP. FPGA is used to generate timing signals, drive signal acquisition chips, and send and receive control commands. DSP is mainly used for the extraction and processing of high-speed data signals.

The laser radar alignment angle adjustment module is composed of a motor control board, a mechanical arm and a transmission structure. The motor control board is placed in the control box, and is used to receive the adjustment instructions of the data acquisition and processing module in real time; the transmission structure is the connection structure between the motor control board and the mechanical arm, and through the transmission of the transmission structure, the mechanical arm Turn in the direction specified by the motor control board. According to the calculated solar altitude angle, adjust the support direction of the mechanical support arm of the laser radar array to control the alignment angle of the laser radar array and avoid the influence of direct sunlight.

The catenary height output module is used to output catenary height information feedback to the pantograph control terminal in real time.

The GPS solar altitude positioning module and data acquisition and processing module described in this embodiment are fixed inside the measurement system, and the lidar alignment angle adjustment module is fixed on the top of the measurement system.

In this embodiment, the data acquisition and processing module adopts the GPS positioning module to read the current position and time information of the train, and calculate the current position sun altitude angle according to the calculation formula of the sun altitude angle. According to the calculated solar altitude range, in conjunction with Figure 4, the GPS solar altitude positioning module, data acquisition and processing module, and the motor control board in the laser radar alignment angle adjustment module are used as the circuit control processing part of the entire measurement system , and placed in the control box on the upper surface of the train; the angle adjustment module is used to judge and adjust the alignment angle of the lidar array. After the angle adjustment is completed, the data acquisition and processing module will sequentially drive and control the laser radar array at equal intervals through the timing drive signal, and so on. The laser radar array sequentially transmits the collected scanning data to the data acquisition and processing module. The data processing module extracts and calculates the scanning data to realize the continuous measurement of the height of the catenary wire.

The schematic diagram of the contour curve composed of single-frame scanning data is combined with Fig. 3 . Among them, the minimum distance corresponding to the angle α from the center line is the position corresponding to the catenary wire, and the calculation formula for the height of the wire at this position is:

H＝L cosαsinθ+d

Among them, θ is the angle between the lidar and the horizontal plane, and α is the angle between the catenary scanning position and the position directly in front of the radar scanning. L is the catenary distance measured by the lidar, d is the correction value of the height of the lidar target surface from the upper surface of the train, and H is the height of the catenary from the upper surface of the train.

Claims (4)

1. The train catenary height non-contact measurement system based on the parallel laser radar is fixed at a specified distance in front of a pantograph device at the top of a train; the system is characterized by comprising a laser radar array, a GPS solar altitude angle positioning module, a data acquisition and processing module, a laser radar alignment angle adjusting module and a contact net height output module;

the GPS solar altitude angle positioning module is used for acquiring the current position and time information of the train in real time and calculating the current solar altitude angle; meanwhile, the solar altitude angle information is transmitted to a data acquisition and processing module;

the data acquisition and processing module is used for sending the solar altitude angle information to the laser radar alignment angle adjusting module; the system is also used for sending a time sequence driving signal to the laser radar array, controlling each laser radar in the laser radar array to perform periodic measurement at equal intervals in sequence so as to realize continuous measurement of the height of the contact net lead, and sending the measured contact net height information to the contact net height output module after processing;

the laser radar array is used for receiving a time sequence driving signal sent by the data acquisition and processing module; carrying out rapid positioning scanning and height measurement on the current position of the contact network wire; the collected scanning data are sequentially transmitted to a data collecting and processing module;

the laser radar alignment angle adjusting module adjusts the supporting direction of the mechanical supporting arm of the laser radar array according to the solar altitude angle information sent by the received data collecting and processing module so as to control the alignment angle of the laser radar array;

the overhead line system height output module is used for receiving overhead line system height information of the data acquisition and processing module and feeding back the overhead line system height information to the pantograph control end in real time;

the formula of the height of the contact net from the upper surface of the train is as follows:

H＝Lcosαsinθ+d

in the formula, theta is an included angle between the laser radar and the upper surface of the train, and alpha is an included angle between the scanning position of the overhead line system and the position right in front of the radar scanning position; l is the distance of the contact net measured by the laser radar, d is the corrected value of the height of the target surface of the laser radar from the upper surface of the train, and H is the height of the contact net from the upper surface of the train.

2. The train catenary height non-contact measurement system based on the parallel laser radar of claim 1, wherein the laser radar alignment angle adjustment module is composed of a motor control board, a mechanical arm and a transmission structure; the motor control board is arranged in the control box and used for receiving an adjusting instruction of the data acquisition and processing module in real time; the transmission structure is a connection structure of the motor control panel and the mechanical arm, and the mechanical arm is driven to rotate to the designated direction of the motor control panel through the transmission of the transmission structure.

3. The system for measuring the height of the train catenary in a non-contact manner based on the parallel laser radar as claimed in claim 1, wherein the laser radar array is fixed at the tail end of the laser radar alignment angle adjusting module, and the scanning field of view is aligned with all distributed position ranges of zigzag wires of the catenary at a specified distance in front.

4. The parallel lidar based train catenary height non-contact measurement system according to claim 1 or 3, wherein the specified distance is in a range of 1-2 m.