CN108761481A - A kind of extension clamp angle measuring system and measurement method, semitrailer - Google Patents

Abstract

The invention provides a hanging box included angle measuring system and a measuring method, and a semi-trailer. The hanging box included angle measuring system includes a laser radar, an analysis device, and a reflecting plate with a reflecting surface, the reflecting surface faces the laser radar, wherein: the laser radar is fixed At the rear of the tractor, it is used to emit laser and receive the laser point cloud reflected by the reflector, and send the received laser point cloud to the analysis device; the reflector is fixed on the front of the semi-trailer to reflect the laser radar Laser; the analysis device is connected with the laser radar signal, and is used to calculate the angle of the trailer according to the received laser point cloud. The technical solution of the present invention, the system for measuring the angle of the trailer is simple in structure, easy to install, and does not need to change the existing structure of the semi-trailer. It is easy to implement and has high measurement accuracy.

Description

A system and method for measuring the included angle of a trailer, and a semi-trailer

technical field

The invention relates to the technical field of vehicles, in particular to a system and method for measuring the included angle of a trailer, and a semi-trailer.

Background technique

A semi-trailer is a heavy-duty transport vehicle that connects a tractor and a trailer through a traction pin. Compared with a single truck, a semi-trailer can improve the comprehensive economic benefits of road transportation. With the development of automatic driving technology, The trailer angle (the trailer angle refers to the angle between the tractor and the trailer) has become the focus of research as the basis of automatic driving planning and control points.

At present, there are two ways to measure the angle of the hanging box:

Method 1, based on the angle detection of the angle sensor, the angle sensor installed near the traction pin measures the angle of the trailer. Although this method can measure the angle between the tractor and the trailer, it needs to change the structure near the traction pin, and the installation is complicated and may introduce security risks;

Method 2, based on the angle measurement method of magnetic field strength, measures the angle of the hanging box by detecting the received magnetic field signal, but this method requires the installation of two magnetic field transmitters and a receiver, the structure is complex and the magnetic field is easily disturbed. Therefore, it is particularly important to design a system and method for measuring the included angle of the trailer, which has a simple structure, does not need to change the connecting mechanism, and can realize fast and accurate measurement, and a semi-trailer.

Contents of the invention

The invention provides a trailer box included angle measurement system and method, and a semi-trailer. The trailer box included angle measurement system has a simple structure, is easy to install, does not need to modify the existing structure of the semi-trailer, is easy to implement, and has high measurement accuracy.

In an embodiment of the present invention, the first aspect provides a hanging box angle measurement system, the hanging box angle measurement system includes a laser radar, an analysis device and a reflective plate with a reflective surface, the reflective surface faces the laser radar, wherein :

The laser radar is fixed at the tail of the tractor and is used to emit laser light, receive the laser point cloud reflected by the reflector, and send the laser point cloud to the analysis device;

The reflector is fixed on the front of the trailer, and is used to reflect the laser radar to emit laser light through the reflective surface;

An analysis device, connected to the laser radar signal, is used to calculate the angle of the hanging box according to the laser point cloud received from the laser radar.

The embodiment of the present invention, in the second aspect, provides a method for measuring the included angle of the hanging box, the method is applied to a semi-trailer, the semi-trailer includes a tractor and a trailer, and a hanging box included angle measurement system is arranged on the semi-trailer, the Hanging box included angle measuring system comprises lidar, analyzing device and the reflecting plate with reflective surface, and described reflective surface faces described lidar; Method comprises:

Laser radar emits laser light;

The reflector reflects the laser radar and emits laser light through the reflective surface;

The laser radar receives the laser point cloud reflected by the reflector, and sends the laser point cloud to the analysis device;

The analysis device calculates the angle between the hanging box according to the laser point cloud received from the laser radar.

Embodiments of the present invention, in a third aspect, provide a semi-trailer, including the aforementioned system for measuring the included angle of the trailer.

In the embodiment of the present invention, a hanging box angle measurement system is provided in the semi-trailer, and the hanging box included angle measurement system includes a laser radar, a reflector and an analysis device, the laser radar emits laser light and receives the laser point cloud reflected by the reflector, And send the received laser point cloud to the analysis device, and the analysis device calculates the angle of the hanging box according to the received laser point cloud. The trailer angle measurement system provided by the embodiment of the present invention has a simple structure, is easy to install, does not need to modify the existing structure of the semi-trailer, and is easy to implement.

Description of drawings

Fig. 1 is the structural representation of a kind of semi-trailer provided by the embodiment of the present invention;

Figure 2 is an enlarged schematic view of position A in Figure 1;

Fig. 3 is a schematic structural view of the trailer part along the B direction in a semi-trailer provided by an embodiment of the present invention;

4 is a schematic diagram of a laser radar coordinate system established in an embodiment of the present invention;

Fig. 5 is one of the schematic diagrams of determining the included angle of the hanging box in the embodiment of the present invention;

Fig. 6 is the second schematic diagram of determining the angle of the hanging box in the embodiment of the present invention;

Fig. 7 is one of the flow charts of a method for measuring the included angle of the hanging box provided by the embodiment of the present invention;

Fig. 8 is the second flow chart of a method for measuring the included angle of the hanging box provided by the embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Embodiment one

As shown in Fig. 1, it is the structural representation of hanging box included angle measuring system 3 in the embodiment of the present invention, and this hanging box included angle measuring system 3 comprises laser radar 31, analysis device (not shown in the figure) and has reflective surface The reflecting plate 32, the reflecting surface faces the laser radar 31, wherein:

The laser radar 31 is fixed on the tail of the tractor 1, and is used to emit laser light, receive the laser point cloud reflected by the reflector 32, and send the laser point cloud to the analysis device.

In the embodiment of the present invention, the lidar 31 may be a single-line lidar, or a multi-line lidar, such as a 4-line, 8-line, 16-line, 32-line, or 64-line lidar.

The reflector 32 is fixed on the front of the trailer 2, and is used to reflect the laser emitted by the laser radar 31 through the reflective surface;

The analysis device is connected with the laser radar 31 signal, and is used for calculating the hanging box angle according to the laser point cloud received from the laser radar 31 .

In one example, the laser radar 31 can be fixed on the tail of the tractor 1 by but not limited to the following methods: welded on the tail of the tractor 1; fastened to the tail of the tractor 1 by a first fastener, the first Fasteners may be screws, bolts, etc., which are not strictly limited in this application.

In one example, the reflector 32 can be fixed on the front of the trailer 2 by but not limited to: welding on the front of the trailer 2; Fasteners may be screws, bolts, etc., which are not strictly limited in this application.

Preferably, in order to further reduce changes to the existing structure of the trailer, in the embodiment of the present invention, some existing structures of the trailer can be fully utilized to install the laser radar 31 and the reflector 32 . For example, the bottom of the semi-trailer is provided with a longitudinal beam and a beam, and a support beam is provided at the bottom of the beam (the support beam refers to the beam used to support the trailer when the trailer is not hung on the tractor; the support beam is generally fixed at the bottom of the semi-trailer. On the beam; both sides of the support beam contain a telescopic support leg. When the trailer is hung on the tractor through the traction pin, the two support legs of the support beam are in the retracted state; when the trailer is not hung on the tractor , the two supporting legs of the supporting beam are extended and support the tractor), and the laser radar 31 and the reflector 32 can be respectively fixed on the tail of the tractor 1 and the front of the trailer 2 through the supporting beam. Therefore, in an example, the aforementioned first fastener is the first support beam 33, the first support beam 33 is fixed on the beam at the rear of the tractor 1, and the laser radar 31 is fixed on the first support beam 33. The supporting beam 33 faces away from the side of the tractor 1 and emits laser light toward the reflecting plate 32 . In one example, the aforementioned second fastener is the second support beam 34, the second support beam 34 is fixed to the front lower crossbeam 21 of the semi-trailer, and the reflector 32 is fixed to the second support The beam 34 faces away from the beam 21 , and the reflective surface faces the laser radar 31 . In the embodiment of the present invention, the number of the second support beams 34 is two, and the two second support beams 34 clamp the beam 21 from the front and rear sides of the beam 21 . As shown in Figure 2 and Figure 3.

In the above hanging box included angle measurement system 3, the beam 21 is first clamped from the front and rear sides of the beam 21 by two second support beams 34, and then the reflection plate 32 is quickly installed and fixed on the second support beam 34 away from the beam 21 , and ensure that the reflective surface faces the laser radar 31. When the laser radar 31 can emit laser light to the reflective plate 32, the reflective surface will reflect the laser light to the laser radar 31. Since the above-mentioned installation process is based on the existing structure on the trailer 2, it will not be installed during installation. No need to make any changes to the structure of the existing semi-trailer, it can be installed without traces, and the structure is simple, the installation is convenient and fast, and the connection mechanism does not need to be changed.

Preferably, because aluminum profiles are widely used due to their good machinability, easy molding, and easy availability of materials, the first support beam 33 and the second support beam 34 can be aluminum profiles in the embodiment of the present invention , can also be a profile structure made of other materials.

Preferably, in an example, the analysis device may include a region of interests filtering module and a random sampling consensus algorithm module, wherein:

The interest area filter module is connected to the laser radar 31 signal, and is used to receive the laser point cloud sent by the laser radar 31, and obtain the reflection plate 32 from the received laser point cloud. Rotate within the preset angle range to make the covered To the laser point cloud of the region, and transmit the obtained laser point cloud to the random sampling consensus algorithm module;

The random sampling consistent algorithm module is connected with the signal of the interested area filter module, and calculates the angle of the hanging box according to the received laser point cloud.

In the embodiment of the present invention, in the above-mentioned hanging box angle measurement system 3, the preset angle range can be flexibly set by those skilled in the art according to the actual situation, that is, those skilled in the art determine the laser point fed back by the laser radar 31 based on experience. In the cloud, the laser point cloud falling within the angle range is the laser point cloud reflected by the reflector 32 , for example, the angle range can be set to -45°～+45°.

On the basis of the above-mentioned hanging box angle measurement system 3, in order to further ensure the accuracy of the measured hanging box angle, the analysis device can also include a Coleman filter module, and the Coleman filter module is consistent with the random sampling algorithm The module signals are connected; after the random sampling consensus algorithm module calculates the included angle of the hanging box, it sends the included angle of the hanging box to the Coleman filter module; the Coleman filter module performs noise reduction processing on the received included angle of the hanging box.

In the above-mentioned hanging box angle measurement system 3, due to the manufacturing error of the reflector 32, the reflector 32 itself cannot be guaranteed to be 100% smooth, and the laser radar 31 itself also has observation errors, so that the hanging box calculated by the random sampling consistent algorithm module There is a certain error in the included angle of the box. The phenomenon shown is that when the vehicle is stationary, the included angle will also jump by plus or minus 1°~2°. In order to solve this problem, the Coleman filter module performs noise reduction processing on the received hanging box angle, and combines the output result of the random sampling consensus algorithm module with the simple kinematic model of the angle change to obtain a smooth output result. Not only can it ensure that the error of the measurement data of the angle of the hanging box in the static state is within plus or minus 0.5°, but it can also ensure that the measurement data can change in real time when the angle of the hanging box changes rapidly, without obvious delay.

In the embodiment of the present invention, after the laser radar 31 is installed, the laser radar coordinate system is established, and the position information of the laser point cloud sent by the laser radar is based on the laser radar coordinate system. For example, the laser radar as shown in FIG. 4 can be established Coordinate System.

In an example, the random sampling consensus algorithm module calculates the included angle of the hanging box according to the received laser point cloud, which can be implemented in the following ways: fitting a straight line equation according to the received laser point cloud; inverting the slope of the straight line equation Cut the calculation to get the included angle of the hanging box, as shown in Figure 5.

In one example, the random sampling consensus algorithm module calculates the included angle of the hanging box according to the received laser point cloud, which can be specifically implemented in the following manner: calculate the position of the reflector 32 in the laser radar coordinate system according to the received laser point cloud Point p; starting from the point p and ending at the connection point o' between the tractor 1 and the trailer 2, determine the straight line equation, and calculate the arc tangent of the slope of the straight line equation to obtain the included angle of the hanging box, as shown in Figure 6.

In a preferred implementation manner, since the reflection effect of the surface of the steel plate is better, the reflection plate 32 in the embodiment of the present invention may be a steel plate. Certainly, those skilled in the art may also choose other materials with better reflection effects to make the reflecting plate 32 , which is not strictly limited in this application.

Embodiment two

Based on the same concept of the system for measuring the included angle of the hanging box provided in the first embodiment, the second embodiment of the present invention provides a method for measuring the included angle of the hanging box, which is applied to a semi-trailer, and the semi-trailer includes a tractor and a trailer The semi-trailer is provided with a hanging box included angle measurement system as shown in Embodiment 1. The hanging box included angle measuring system includes a laser radar, an analysis device and a reflector. The structure of the hanging box included angle measuring system is detailed in the embodiment. A related content will not be repeated here. The flow chart of this method comprises the following steps as shown in Figure 7:

Step S101, the lidar emits laser light;

Step S102, the reflecting plate reflects the laser radar through the reflecting surface to emit laser light;

Step S103, the laser radar receives the laser point cloud reflected by the reflector, and sends the laser point cloud to the analysis device;

Step S104, the analysis device calculates the angle between the hanging boxes according to the laser point cloud received from the laser radar.

In one example, the analysis device in step S104 can specifically calculate the angle of the hanging box in the following manner, which includes steps A1 to A2, wherein:

Step A1. Obtain the laser point cloud of the area covered when the reflector rotates within a preset angle range from the received laser point cloud.

Step A2. Calculate the included angle of the hanging box according to the acquired laser point cloud.

Preferably, in order to further improve the accuracy of the included angle of the hanging box, in the embodiment of the present invention, the process shown in FIG. 7 also includes the following step 105, as shown in FIG. 8:

Step 105, the analysis device performs noise reduction processing on the calculated included angle of the hanging box.

In the embodiment of the present invention, the analysis device may include a rights area filtering module and a random sampling consensus algorithm module, the aforementioned step A1 is performed by the rights area filtering module, and step A2 is performed by the random sampling consensus algorithm module.

In the embodiment of the present invention, after the laser radar 31 is installed, the laser radar coordinate system is established, and the position information of the laser point cloud sent by the laser radar is based on the laser radar coordinate system. For example, the laser radar as shown in FIG. 4 can be established Coordinate System.

In an example, the random sampling consensus algorithm module calculates the included angle of the hanging box according to the received laser point cloud, which can be implemented in the following ways: fitting a straight line equation according to the received laser point cloud; inverting the slope of the straight line equation Cut the calculation to get the included angle of the hanging box, as shown in Figure 5.

In one example, the random sampling consensus algorithm module calculates the included angle of the hanging box according to the received laser point cloud, which can be specifically implemented in the following manner: calculate the position of the reflector 32 in the laser radar coordinate system according to the received laser point cloud Point p; starting from the point p and ending at the connection point o' between the tractor 1 and the trailer 2, determine the straight line equation, and calculate the arc tangent of the slope of the straight line equation to obtain the included angle of the hanging box, as shown in Figure 6.

Embodiment three

The third embodiment of the present invention also includes a semi-trailer, the semi-trailer includes a tractor and a trailer, and a system for measuring the included angle of the trailer as shown in any one of the first embodiments.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (13)

1. A hanging box angle measurement system, characterized in that, comprises a laser radar, an analysis device and a reflector with a reflective surface, the reflective surface is towards the laser radar, wherein: The laser radar is fixed at the tail of the tractor and is used to emit laser; and, receives the laser point cloud reflected by the reflector, and sends the laser point cloud to the analysis device; The reflector is fixed on the front of the trailer, and is used to reflect the laser radar to emit laser light through the reflective surface; An analysis device, connected to the laser radar signal, is used to calculate the angle of the hanging box according to the laser point cloud received from the laser radar. 2. The system for measuring the included angle of the hanging box according to claim 1, wherein the laser radar is fixed to the rear of the tractor through a first fastener. 3. The hanging box included angle measurement system according to claim 1, wherein the first fastener is a first support beam, and the first support beam is fixed to the crossbeam at the tail of the tractor, so The lidar is fixed on the side of the first support beam away from the tractor, and emits laser light toward the reflection plate. 4. The system for measuring the included angle of the trailer according to claim 1, characterized in that, the reflector is fixed to the front of the trailer through a second fastener. 5. The hanging box included angle measurement system according to claim 4, wherein the second fastener is a second support beam, and the second support beam is fixed to the front lower crossbeam of the trailer, The reflection plate is fixed on the second support beam away from the beam, and the reflection surface faces the laser radar. 6. The hanging box angle measurement system as claimed in claim 5, wherein the number of the second support beams is two, and the two second support beams clamp the two sides from the front and rear sides of the crossbeam. beam. 7. The system for measuring the included angle of the hanging box according to claim 1, wherein the reflector is a steel plate. 8. The hanging box included angle measurement system as claimed in claim 1, wherein said analysis device includes a signal-connected area filter module with interest and a random sampling consistent algorithm module, wherein: The interested area filtering module is connected to the laser radar signal, and is used to receive the laser point cloud sent by the laser radar, and obtain the rotation of the reflector within a preset angle range from the received laser point cloud The laser point cloud of the covered area, and the obtained laser point cloud is sent to the random sampling consistent algorithm module; The random sampling consistent algorithm module calculates the included angle of the hanging box according to the received laser point cloud. 9. The hanging box included angle measuring system as claimed in claim 8, wherein said analysis device also includes a Coleman filter module, and said Coleman filter module is connected with said random sampling consistent algorithm module signal; The random sampling consensus algorithm module is further used to send the calculated hanging box angle to the Coleman filter module; The Coleman filter module is used to perform noise reduction processing on the received hanging box angle. 10. A method for measuring the included angle of a hanging box, which is characterized in that it is applied to a semi-trailer, the semi-trailer includes a tractor and a trailer, and the semi-trailer is provided with a hanging box included angle measuring system, the hanging box included angle measuring system Comprising a lidar, an analysis device, and a reflective plate with a reflective surface facing the lidar; the method comprising: Laser radar emits laser light; The reflector reflects the laser radar and emits laser light through the reflective surface; The laser radar receives the laser point cloud reflected by the reflector, and sends the laser point cloud to the analysis device; The analysis device calculates the angle between the hanging box according to the laser point cloud received from the laser radar. 11. The method for measuring the included angle of the hanging box according to claim 10, wherein the analysis device calculates the included angle of the hanging box according to the laser point cloud received from the laser radar, specifically comprising: Obtain the laser point cloud of the area covered when the reflector rotates within the preset angle range from the received laser point cloud; According to the obtained laser point cloud, the angle of the hanging box is calculated. 12. The method for measuring the included angle of hanging boxes as claimed in claim 11, further comprising: The analysis device performs noise reduction processing on the calculated included angle of the hanging box. 13. A semi-trailer, comprising a tractor and a trailer connected to the tractor, characterized in that it further comprises the trailer angle measurement system according to any one of claims 1-9.