Auxiliary measuring method for hinge angle of unmanned articulated vehicle based on millimeter wave radar
Technical Field
The invention belongs to the field of vehicle control, and particularly relates to an auxiliary measuring method for an articulation angle of an unmanned articulated vehicle based on a millimeter wave radar.
Background
An articulated vehicle is formed by connecting a plurality of rigid bodies by means of an articulation device, and the direction of movement of the vehicle is changed by means of mutual rotation of the articulation.
In recent years, the control technology of the unmanned articulated vehicle is gradually developed, the articulated vehicle is easy to generate instability and sideslip phenomena during steering and lateral adjustment compared with a single rigid body vehicle, and in the unmanned articulated vehicle control, the articulation angle of a plurality of rigid body articulation parts of the articulated vehicle directly influences the smoothness and stability of the vehicle during driving. Therefore, the measured degree of articulation angle is an important quantity for vehicle control, and the accuracy of its articulation angle is extremely important to the effectiveness of vehicle control.
At present, the hinge angle of the articulated vehicle is generally obtained by directly measuring by using an angle sensor, the measuring method has higher requirements on the measuring precision and the mounting precision of the sensor, and the adaptation degrees of the hinge parts of different articulated vehicles are different, so that the measuring precision of the hinge angle of the articulated vehicle is influenced, and the measuring practicability is poor. In addition, a laser range finder and a camera are arranged among the rigid bodies, and the mutual relation among the rigid bodies is measured to obtain the hinge angle in an auxiliary measurement mode.
Disclosure of Invention
The invention aims to provide the auxiliary measuring method for the articulation angle of the unmanned articulated vehicle based on the millimeter wave radar, which is simple to operate, high in measuring precision and has an auxiliary measuring effect.
The technical scheme of the invention is as follows:
an articulation angle auxiliary measurement method of an unmanned articulated vehicle based on a millimeter wave radar comprises the following steps:
(1) installing 2 millimeter wave radars on the side surface of the front rigid body of the articulated vehicle, installing 2 millimeter wave radars on the side surface of the rear rigid body, detecting the base surface by each millimeter wave radar, and sequentially obtaining the distance between each millimeter wave radar and the base surface as b2、a2、b1、a1;
(2) According to the relative distance S of the 2 millimeter wave radars on the front rigid body in the step (1)2Relative distance S of 2 millimeter wave radars on rear rigid body1And (2) calculating the relative included angle alpha of the front rigid body according to the distance between each millimeter wave radar and the base surface obtained by detection in the step (1)2Relative included angle alpha with rear rigid body1Calculated by the following formula:
(3) obtaining the relative included angle alpha of the front rigid body according to the step (2)2And rear rigid bodyRelative included angle alpha1And calculating a relative articulation angle alpha of the front rigid body and the rear rigid body of the articulated vehicle at the articulation position, wherein the relative articulation angle alpha is calculated by the following formula:
α=α2-α1;
(4) calculating an absolute articulation angle α' in the control of the articulated vehicle from the relative articulation angle α obtained in the step (3), by the following formula:
α′=90-α。
in the above technical solution, the absolute hinge angle degree obtained in the step (4) is defined to vary within 0-180 °, and the hinge angle degree is 90 ° when the front rigid body and the rear rigid body are opposite.
In the above technical solution, the base surface has rigidity and the surface of the base surface is flat.
Another object of the present invention is to provide an application of the method for auxiliary measurement of the hinge angle of the unmanned articulated vehicle based on millimeter wave radar in the tunnel construction environment, wherein the foundation surface is the side wall of the tunnel as the foundation surface, and the measurement of the relative hinge angle is realized through the above steps (1) - (4).
Another object of the present invention is to provide an application of the method for auxiliary measurement of the hinge angle of the unmanned articulated vehicle based on millimeter wave radar in the dam construction environment, wherein the foundation surface is the side wall of the dam, and the measurement of the relative hinge angle is realized through the above steps (1) - (4).
The invention has the advantages and positive effects that:
1. the unmanned articulated vehicle runs to the base surface to be used as a reference surface for detection of the millimeter wave radar, the position distance relation of the front rigid body and the rear rigid body of the articulated vehicle relative to the base surface is measured through the millimeter wave radar, the mounting distance between the millimeter wave radars mounted on the front rigid body and the rear rigid body of the articulated vehicle is combined to convert to obtain the angle of the hinge position of the front rigid body and the rear rigid body, the base surface is built in a vehicle running environment to assist the millimeter wave radar to measure, the complexity and the mounting cost of the millimeter wave radars are reduced, and the practicability and the feasibility of the measuring method are improved.
2. The measuring method has low requirements on the installation position and the cleanliness of the millimeter wave radar, and the hinge angle of the hinge joint is accurately measured by the aid of the base surface.
Drawings
Fig. 1 is a schematic view of the measurement principle of the present invention.
In the figure:
1. front rigid body 2 of articulated vehicle, rear rigid body 3 of articulated vehicle, first millimeter wave radar
4. A second millimeter wave radar 5, a base surface 6, and a third millimeter wave radar
7. Fourth millimeter wave radar 8, articulated vehicle articulation
Detailed Description
The present invention will be described in further detail with reference to specific examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of the invention in any way.
Example 1
As shown in fig. 1, the method for auxiliary measurement of the articulation angle of the unmanned articulated vehicle based on the millimeter wave radar of the invention comprises the following steps:
(1) installing a first millimeter wave radar and a second millimeter wave radar on the side surface of a front rigid body of an articulated vehicle, installing a third millimeter wave radar and a fourth millimeter wave radar on the side surface of a rear rigid body, wherein a base surface exists in the running environment of the articulated vehicle, the base surface is arranged on the side surface of the running direction of the articulated vehicle, the base surface is used as a running area constraint surface of the unmanned articulated vehicle, the base surface is detected through each millimeter wave radar, and the distances between the first millimeter wave radar, the second millimeter wave radar and the fourth millimeter wave radar and the base surface are sequentially obtained as b2、a2、b1、a1;
(2) According to the relative distance S between the first millimeter wave radar and the second millimeter wave radar on the rigid body before the step (1)2And the relative distance S between the third millimeter wave radar and the fourth millimeter wave radar on the rear rigid body1And b detected in step (1)2、a2、b1、a1Meter for measuringCalculating the relative included angle alpha of the front rigid body1Relative included angle alpha with rear rigid body2Calculated by the following formula:
(3) obtaining the relative included angle alpha of the front rigid body according to the step (2)1Relative included angle alpha with rear rigid body2And calculating a relative articulation angle alpha of the front rigid body and the rear rigid body of the articulated vehicle at the articulation position, wherein the relative articulation angle alpha is calculated by the following formula:
α=α2-α1;
(4) calculating an absolute articulation angle alpha' in the control of the articulated vehicle according to the relative articulation angle alpha obtained in the step (3), and calculating by the following formula:
α′=90-α
wherein, the absolute hinge angle degree obtained by definition changes within 0-180 degrees, and the hinge angle degree is 90 degrees when the front rigid body and the rear rigid body are opposite.
Further, the base surface has rigidity and the surface of the base surface is flat.
Example 2
Based on embodiment 1, the method for auxiliary measurement of the articulation angle of the unmanned articulated vehicle based on the millimeter wave radar is applied to a tunnel construction environment, a tunnel exists in the operation environment of the articulated vehicle, and the relative articulation angle between the front rigid body and the rear rigid body of the articulated vehicle is calculated by using the inner side wall of the tunnel as a base surface through the steps (1) to (4) in embodiment 1.
Example 3
Based on embodiment 1, the method for auxiliary measurement of the articulation angle of the unmanned articulated vehicle based on the millimeter wave radar is applied to a dam construction environment, a dam exists in the operation environment of the articulated vehicle, and the relative articulation angle between the front rigid body and the rear rigid body of the articulated vehicle is calculated by using the side wall of the dam as a base surface through the steps (1) to (4) in embodiment 1.
Spatially relative terms, such as "upper," "lower," "left," "right," and the like, may be used in the embodiments for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatial terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "lower" can encompass both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
Moreover, relational terms such as "first" and "second," and the like, may be used solely to distinguish one element from another element having the same name, without necessarily requiring or implying any actual such relationship or order between such elements.
The invention has been described in an illustrative manner, and it is to be understood that any simple variations, modifications or other equivalent changes which can be made by one skilled in the art without departing from the spirit of the invention fall within the scope of the invention.