CN110806569A

CN110806569A - Laser radar

Info

Publication number: CN110806569A
Application number: CN201910974902.8A
Authority: CN
Inventors: 杨野; 疏达; 李�远
Original assignee: Benewake Beijing Co Ltd
Current assignee: Benewake Beijing Co Ltd
Priority date: 2019-10-14
Filing date: 2019-10-14
Publication date: 2020-02-18

Abstract

The present disclosure relates to laser radars, and particularly to a variable focus laser radar. The laser radar comprises a transmitting light source, a transmitting optical module, a receiving optical module and a receiving end, wherein the transmitting light source is used for generating an emergent light beam, the emergent light beam is emitted to a target through the transmitting optical module, an echo light beam returned by the target is emitted into the receiving end through the receiving optical module, the transmitting optical module and the receiving optical module can change focal lengths, and the transmitting optical module and the receiving optical module are an optical machine zooming device or a liquid lens device. The variable-focus optical machine zooming device or the liquid lens device is adopted as the transmitting optical module and the receiving optical module, so that the focal lengths of the transmitting optical module and the receiving optical module are adjustable, the receiving optical module is variable-focus, and the optimal imaging quality under different ranging ranges can be obtained; the receiving optical module and the transmitting optical module can be zoomed, and the switching and the compatibility of the large-angle distance measurement and the long-distance measurement are realized.

Description

Laser radar

Technical Field

The application relates to the field of laser radars, in particular to a variable-focus laser radar.

Background

The transmitting device of the laser radar uses a corresponding optical beam transmitting system, and the receiving device uses a corresponding beam receiving lens system, so that the energy utilization rate of the transmitting and receiving systems is improved as much as possible. In general, both the transmitting device and the receiving device of the optical radar are fixed, and the focal plane and the focal depth are generally not changeable, i.e. not variable in focal length, so that the range of measurement and the angle of view are limited. When the object to be measured is not in the imaging focal depth of the optical system, the phenomenon of out-of-focus imaging on the object plane occurs, and the imaging quality is rapidly reduced. For radar systems, the effect of the depth of focus causing defocus is reflected in: the imaging quality is rapidly deteriorated, the mutual interference among detection pixels causes the problems of dragging points and contrast, the single-pixel receiving field of view for reducing the receiving efficiency of return signal light is enlarged, and the interference of ambient light is serious. There is therefore a need for a lidar which can be zoomed.

Disclosure of Invention

The embodiment of the application provides a variable-focus laser radar, and solves the problem that the prior art cannot zoom.

A laser radar comprises a transmitting light source, a transmitting optical module, a receiving optical module and a receiving end, wherein the transmitting light source is used for generating an emergent light beam, the emergent light beam is emitted to a target through the transmitting optical module, an echo light beam returned by the target is emitted to the receiving end through the receiving optical module, the laser radar is characterized in that the focal length of the transmitting optical module and the focal length of the receiving optical module can be changed, and the transmitting optical module and the receiving optical module are optical machine zooming devices or liquid lens devices.

In a possible implementation manner, the optical machine zoom device includes a zoom lens group, a transmission mechanism, and a motor, the zoom lens group is connected to the transmission mechanism, an optical axis of the zoom lens group is consistent with an optical axis of the transmitting light source or the receiving end, and the motor is connected to the transmission mechanism, and drives the zoom lens group to move along the optical axis through the transmission mechanism.

In a possible implementation manner, the zoom lens group is a plurality of lenses, and is divided into a zoom lens and a fixed lens, the zoom lens is driven to a specified position by the transmission mechanism, and the fixed lens is fixed.

In a possible implementation manner, the number of the zoom lenses is 1 or more, and the number of the fixed lenses is 1 or more.

In a possible implementation manner, the zoom range of the optical machine zoom device is 2-15 mm.

In one possible implementation, the motor is a stepper motor or an ultrasonic motor.

In a possible implementation manner, the liquid lens device includes a liquid lens, and positive and negative electrodes, where the positive and negative electrodes are used to supply power to the liquid lens, and the liquid lens adjusts the curvature of the curved surface after being powered on, so as to change the focal length of the liquid lens.

In a possible implementation manner, the liquid lens apparatus further includes a control module, and the control module is connected to the positive electrode and the negative electrode and is used for controlling the liquid lens to change the curvature.

In one possible implementation, the liquid lens apparatus has a zoom range of 2-15 mm.

In a possible implementation manner, the laser radar further includes one or more lenses, and the lenses are disposed between the liquid lens and the target to be measured.

The variable-focus optical machine zooming device or the liquid lens device is adopted as the transmitting optical module and the receiving optical module, so that the focal lengths of the transmitting optical module and the receiving optical module are adjustable, the receiving optical module is variable in focus, and the optimal imaging quality in different ranging ranges can be obtained; the receiving optical module and the transmitting optical module can be zoomed, and the switching and the compatibility of the large-angle distance measurement and the long-distance measurement are realized.

Drawings

Fig. 1 is a schematic diagram of a laser radar employing an optical-mechanical zoom device according to an embodiment of the present application.

Fig. 2 is a schematic view of an optical mechanical zoom principle according to an embodiment of the present application.

Fig. 3 is a schematic diagram of a lidar employing a liquid lens apparatus according to an embodiment of the present disclosure.

In the figure: 1. an emission light source; 2. a receiving end; 3. a zoom lens group; 4. a transmission structure; 5. a zoom motor; 6. a zoom lens; 7. fixing the lens; 8. a liquid lens; 9. positive and negative electrodes; 10. a focusing motor; 11. a lens.

Detailed Description

The technical scheme of the application is further explained by the specific implementation mode in combination with the attached drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be used. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

As shown in fig. 1, a laser radar according to an embodiment of the present application includes a transmitting light source 1, a transmitting optical module, a receiving optical module, and a receiving end 2, where the transmitting light source 1 is configured to generate an outgoing light beam, the outgoing light beam is emitted to a target through the transmitting optical module, an echo light beam returned by the target is emitted to the receiving end 2 through the receiving optical module, the transmitting optical module and the receiving optical module may change focal lengths, and the transmitting optical module and the receiving optical module are optical machine zoom devices. The zoom front focal length of the transmitting optical module and the receiving optical module is set to f 1.

The optical parts of the transmitting system and the receiving system of the existing optical radar are usually fixed and non-adjustable. This results in a flash radar with a large field angle (non-scanning area array radar) with a very close range due to too diffuse transmission energy and too low energy density in a space angle. The radar with a long measuring range has an extremely small detection field of view. And the two characteristics can not be switched with each other, so that the applicable environment of the radar is greatly limited.

The variable-focus optical machine zoom device is used as the transmitting optical module and the receiving optical module, so that the focal lengths of the transmitting optical module and the receiving optical module are adjustable, the receiving optical module is variable, and the optimal imaging quality in different distance measuring ranges can be obtained; the near detection part can reduce the focal length due to sufficient energy, thereby realizing detection at a larger angle; when measuring far, the energy density and receiving efficiency decrease rapidly with distance, thus increasing the focal length, reducing the detecting visual field, increasing the energy density, and realizing the farther detecting range. The receiving optical module and the transmitting optical module can be focused and focused, and switching and compatibility of large-angle distance measurement and long-distance measurement are realized.

As shown in fig. 2, an optical zoom device is used as an emitting optical module to realize zooming. The optical machine zooming device comprises a zooming lens group 3, a transmission mechanism 4 and a motor, wherein the zooming lens group 3 is connected with the transmission mechanism 4, the optical axis of the zooming lens group is consistent with that of the transmitting light source 1 or the receiving end 2, the motor is connected with the transmission mechanism 4, and the zooming lens group 3 is driven to move along the optical axis through the transmission mechanism 4.

Before zooming, the focal length of the optical machine zooming device is f 1; when the zoom lens group 3 is zoomed, the motor moves the zoom lens group 3 to a specified position according to the instruction, thereby changing the focal length characteristic of the zoom lens group 3 and obtaining a specified lens focal length f 2. When the emission light source 1 is not changed, the change in focal length effects a change in the field of view of the emission by an amount Δ f. The zoom principle of the receiving optical module is the same as that of the transmitting optical module.

The zoom operation changes the intrinsic characteristics of the optical device, particularly the focal length. The focusing operation is still required after zooming. During focusing, the whole zoom lens group 5 moves, and the moving distance required by the zoom lens group 5 is related to the object distance and the parameters of the lens; the characteristics of the lens can be input in advance, and the object distance is obtained by ranging of a radar system. Through calculation and table lookup, the required change amount is converted into a control signal of a motor, and the motor is driven to move the lens to a corresponding position, so that focusing operation is realized.

The zoom lens group 3 is a plurality of lenses and is divided into a zoom lens 6 and a fixed lens 7, the zoom lens 6 is driven to a specified position by the transmission mechanism 4, and the fixed lens 7 is fixed.

As shown in fig. 2, since the lenses to be moved for zooming and focusing are different, the motors are also divided into a zoom motor 5 and a focus motor 10, the zoom motor 5 is connected with the zoom lens 6 through the transmission mechanism 4, the focus motor 10 is connected with the zoom lens group 3 through the transmission mechanism 4, when zooming, the zoom motor 5 drives the zoom lens 6 to a specified position through the transmission mechanism 4, and the fixed lens 7 is fixed. When focusing is required, the focusing motor 10 drives the variable focus lens group 3 to a specified position (not shown) through the transmission mechanism 4.

The number of the zoom lenses is 1 or more, and the number of the fixed lenses is 1 or more.

The zoom range of the optical machine zoom device is 2-15 mm.

The zoom range of the optical machine zoom device is 2-15mm, and the actual requirement is met.

The motor is a stepping motor or an ultrasonic motor.

As shown in fig. 3, the liquid lens apparatus includes a liquid lens 8, and positive and negative electrodes 9, where the positive and negative electrodes 9 are used to supply power to the liquid lens 8, and the liquid lens 8 adjusts the curvature of the curved surface after being powered on, so as to change the focal length of the liquid lens 8.

The liquid lens 8 is a lens using liquid to change the focal length by changing the curvature of the liquid. The more mature liquid lenses today are variable focus optical lenses that utilize the principle of electrowetting on dielectric (EWOD). It can change the shape of the drop by an applied voltage, and thus its focal length.

The liquid lens device further comprises a control module (not shown in the figure), and the control module is connected with the positive electrode 9 and the negative electrode 9 and is used for controlling the liquid lens to change the curvature.

The zoom range of the liquid lens device is 2-15 mm.

The zoom range of the liquid lens device is 2-15mm, and the requirements of practical application are met.

The laser radar further comprises a lens 11, wherein the lens 11 is arranged between the liquid lens 8 and the target to be measured, and the number of the lenses 11 is one or more.

The lens 11 is used to adjust the optical path.

The technical principles of the present application have been described above in connection with specific embodiments. The description is made for the purpose of illustrating the principles of the present application and is not to be construed in any way as limiting the scope of the application. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present application without inventive effort, which shall fall within the scope of the present application.

Claims

1. A laser radar is characterized by comprising a transmitting light source, a transmitting optical module, a receiving optical module and a receiving end, wherein the transmitting light source is used for generating an emergent light beam, the emergent light beam is emitted to a target through the transmitting optical module, an echo light beam returned by the target is emitted to the receiving end through the receiving optical module, the focal length of the transmitting optical module and the focal length of the receiving optical module can be changed, and the transmitting optical module and the receiving optical module are optical machine zooming devices or liquid lens devices.

2. The lidar of claim 1, wherein the optical-mechanical zoom device comprises a zoom lens set, a transmission mechanism, and a motor, the zoom lens set is connected to the transmission mechanism, and has an optical axis coincident with an optical axis of the transmitting light source or the receiving end, the motor is connected to the transmission mechanism, and the transmission mechanism drives the zoom lens set to move along the optical axis.

3. The lidar of claim 2, wherein the variable focus lens assembly comprises a plurality of lenses, which are divided into a variable focus lens and a fixed lens, the variable focus lens is driven to a predetermined position by a transmission mechanism, and the fixed lens is fixed.

4. The lidar of claim 3, wherein the number of zoom lenses is 1 or more and the number of fixed lenses is 1 or more.

5. The lidar of claim 4, wherein the opto-mechanical zoom has a zoom range of 2-15 mm.

6. The lidar of claim 5, wherein the motor is a stepper motor or an ultrasonic motor.

7. The lidar of claim 1, wherein the liquid lens assembly comprises a liquid lens, and positive and negative electrodes for supplying power to the liquid lens, wherein the liquid lens adjusts curvature of the curved surface after being energized, thereby changing a focal length of the liquid lens.

8. The lidar of claim 7, wherein the liquid lens apparatus further comprises a control module coupled to the positive and negative electrodes for controlling the liquid lens to change curvature.

9. The lidar of claim 8, wherein the liquid lens apparatus has a zoom range of 2-15 mm.

10. The lidar of claim 8, further comprising one or more lenses disposed between the liquid lens and the target.