CN117368936A

CN117368936A - Distance measuring device

Info

Publication number: CN117368936A
Application number: CN202311519924.8A
Authority: CN
Inventors: 林修轾
Original assignee: Luxvisions Innovation Ltd
Current assignee: Luxvisions Innovation Ltd
Priority date: 2023-11-14
Filing date: 2023-11-14
Publication date: 2024-01-09

Abstract

A distance measuring device comprises a transmitting module and a receiving module. The emission module includes an optical assembly, a reflection module, and a light source. The optical component has a first irradiated region and a second irradiated region, the first irradiated region and the second irradiated region being adjacent to each other. The light is reflected by the reflection module to irradiate the first irradiation area or the second irradiation area. The light source generates light rays, the light rays generate a first light spot after passing through the first irradiation area, and the light rays generate a second light spot after passing through the second irradiation area. The receiving module is adjacent to the transmitting module, the receiving module comprises a lens group and a sensing assembly, the sensing assembly comprises a plurality of first sensors and a plurality of second sensors, the first sensors receive reflected light of the first light spots reflected by the projection plane through the lens group, and the second sensors receive reflected light of the second light spots reflected by the projection plane through the lens group.

Description

Distance measuring device

Technical Field

The invention relates to a device for measuring the distance between objects.

Background

With the development of automation technology and the rise of the age of the internet of things in recent years, the demand for real-time distance measurement of objects is increasing, for example, in robots, automated production and automatic driving, the real-time distance measurement can be used for navigation and obstacle avoidance; in mobile phone applications, measuring the distance between an object and a device can help a camera to automatically focus or control the brightness of a mobile phone screen or unlock the mobile phone according to the distance between a user and the mobile phone.

In addition, in applications of virtual reality and augmented reality, real-time distance measurement can also increase interactions between virtual and reality according to the distance between the user and the environmental object, and enhance the user's experience in virtual reality and augmented reality.

The current technology for measuring distance includes ultrasonic ranging, sonar ranging, infrared ranging, frequency modulation ranging, etc., and various ranging technologies have a range of distance that can be sensed and a suitable place.

Disclosure of Invention

In view of the above, the present invention provides a distance measuring device, which includes a transmitting module and a receiving module. The emission module includes an optical assembly, a reflection module, and a light source. The optical component has a first irradiated region and a second irradiated region, the first irradiated region and the second irradiated region being adjacent to each other. The light is reflected by the reflection module to irradiate the first irradiation area or the second irradiation area. The light source generates light rays, the light rays generate a first light spot after passing through the first irradiation area, and the light rays generate a second light spot after passing through the second irradiation area. The receiving module is adjacent to the transmitting module, the receiving module comprises a lens group and a sensing assembly, the sensing assembly comprises a plurality of first sensors and a plurality of second sensors, the first sensors receive reflected light of the first light spots reflected by the projection plane through the lens group, and the second sensors receive reflected light of the second light spots reflected by the projection plane through the lens group.

In one embodiment, a collimating mirror is included to collimate the light generated by the light source.

In an embodiment, the collimating mirror is located between the light source and the reflecting module.

In an embodiment, the collimating mirror is located between the reflecting module and the optical component.

In an embodiment, the reflecting module includes a mirror and a driving module, and the driving module drives the mirror to adjust the mirror angle so that the light beam is reflected by the mirror to irradiate the first irradiation area or the second irradiation area.

In an embodiment, the driving module drives the mirror to adjust the mirror angle according to the switching command.

In an embodiment, the driving module drives the mirror to adjust the mirror angle a plurality of times in succession.

In one embodiment, the driving module drives the mirror to adjust the mirror angle according to the sensing results of the plurality of first sensors.

In an embodiment, the plurality of first sensors have measurement thresholds, and the driving module drives the mirror to adjust the mirror angle when the sensing result reaches or exceeds the measurement thresholds.

In an embodiment, the plurality of first sensors and the plurality of second sensors are staggered with each other.

Drawings

FIG. 1 is a schematic side view of a distance measuring device according to an embodiment.

FIG. 2 is a top view of the distance measuring device of FIG. 1, showing the path of light illuminating the first illumination area.

Fig. 3A is a schematic diagram showing a path of the light beam in fig. 2 irradiating the second irradiation region.

FIG. 3B is a schematic diagram of a path of light from the light source illuminating the second illumination area according to an embodiment.

FIG. 4 is a schematic diagram of the distance measuring device of FIG. 2 applied to a short distance measurement.

Fig. 5 is a schematic diagram of a first light spot according to an embodiment.

FIG. 6 is a schematic diagram of the distance measuring device of FIG. 2 applied to remote measurement.

Fig. 7 is a schematic diagram of a second light spot according to an embodiment.

FIG. 8 is a schematic diagram of a sensing assembly according to an embodiment.

FIG. 9 is a schematic diagram of a sensing assembly according to another embodiment.

FIG. 10 is a schematic diagram of a sensing assembly according to yet another embodiment.

Wherein, the reference numerals:

10 distance measuring device

100 transmitting module

120 optical component

122 first irradiation zone

124 second irradiation zone

140 reflecting module

142 mirror

144 drive module

160 light source

170 collimator lens

180 projection plane

200 receiving module

220 lens group

240 sensing assembly

242 first sensor

244 second sensor

LGT light ray

Theta incidence angle

Z1 center

Z2 center

Detailed Description

Referring to fig. 1, fig. 1 is a schematic side view of a distance measuring device according to an embodiment. The distance measuring device 10 includes a transmitting module 100 and a receiving module 200, and the receiving module 200 is adjacent to the transmitting module 100. With further reference to fig. 2, fig. 2 is a top view of the distance measuring device of fig. 1, and shows a path of light illuminating the first illumination area. The emission module 100 includes an optical assembly 120, a reflection module 140, and a light source 160. The optical assembly 120 has a first illumination region 122 and a second illumination region 124, the first illumination region 122 being adjacent to the second illumination region 124. The light LGT is reflected by the reflection module 140 to irradiate the first irradiation region 122 or the second irradiation region 124. The light LGT is generated by the light source 160, and the light LGT generates a first light spot after passing through the first illumination region 122, and the light LGT generates a second light spot after passing through the second illumination region 124.

The receiving module 200 includes a lens group 220 and a sensing component 240, wherein the sensing component 240 includes a plurality of first sensors 242 and a plurality of second sensors 244. The first sensor 242 receives the reflected light of the first spot reflected from the projection plane 180 (see fig. 4) via the lens assembly 220, and the second sensor 244 receives the reflected light of the second spot reflected from the projection plane 180 via the lens assembly 220.

In an embodiment, the adjacent relationship between the receiving module 200 and the transmitting module 100 may be such that the receiving module 200 is located at the left and right sides or the upper and lower sides of the transmitting module 100. In addition, the center of the transmitting module 100 and the center of the receiving module 200 may be located at the same horizontal position (refer to the Z axis of fig. 1), so as to ensure that the receiving module 200 can accurately receive the optical signal of the first light spot or the second light spot and avoid the loss of the optical signal. For example, as shown in the embodiment of fig. 1, the receiving module 200 is disposed at a side of the transmitting module 100, and the height of the center Z1 of the transmitting module 100 (referring to the position of the Z1 in the Z axis shown in fig. 1) is the same as the height of the center Z2 of the receiving module 200 (referring to the position of the Z2 in the Z axis shown in fig. 1), so that adjacent receiving modules 200 and transmitting modules 100 are reached and the center of the transmitting module 100 and the center of the receiving module 200 are located at the same horizontal position.

In one embodiment, the light LGT generated by the light source 160 is collimated light (collimated light). In another embodiment, the light LGT generated by the light source 160 is divergent light (divergent light), such as a point light source (single point light source or multiple point light sources), a geometric image or a line pattern of the light LGT generated by the light source 160.

When the light LGT is divergent light, the distance measuring device 10 may include a collimator 170, and the collimator 170 is used for collimating the light LGT. The purpose of collimating the divergent light into collimated light is to generate a diffraction effect when the light LGT passes through the optical element 120, so as to form a first light spot or a second light spot on the projection plane 180. Specifically, in designing a typical commercial optical element 120, a diffraction structure may be designed based on the collimated light incident optical element 120, and if a divergent light incident optical element 120 is used, an expected diffraction effect may not be generated, and thus a first light spot or a second light spot may not be formed to measure a distance. It should be understood that the optical element 120 is not limited to the design of the diffraction structure based on the collimation of the light incident on the optical element 120.

The collimator 170 may be located between the light source 160 and the reflective module 140 (as shown in fig. 2), or between the reflective module 140 and the optical component 120 (as shown in fig. 3A), so that the light LGT is collimated when passing through the first illumination area 122 or the second illumination area 124. In an embodiment, the optical element 120 itself has a collimation design, so that when the light LGT generated by the light source 160 is divergent light, the aforementioned effect of increasing the accuracy of the distance measurement of the device can be achieved without integrating the collimator 170.

Referring to fig. 2 and 3A, fig. 3A is a schematic diagram showing a path of the light beam in fig. 2 irradiating the second irradiation region. In one embodiment, the light LGT of the light source 160 irradiates the first irradiation area 122 or the second irradiation area 124, which is controlled by the reflection module 140. The reflecting module 140 includes a reflecting mirror 142 and a driving module 144, the reflecting mirror 142 reflects the light LGT generated by the light source 160, and the driving module 144 drives the reflecting mirror 142 to adjust the mirror angle so that the light LGT irradiates the first irradiation area 122 or the second irradiation area 124, respectively.

The mirror angle of the mirror 142 includes a first angle at which the light LGT irradiates the first irradiation region 122, and a second angle at which the light LGT irradiates the second irradiation region 124. Specifically, the reflecting surface of the reflector 142 is disposed at a first angle in a direction of emitting the light LGT toward the light source 160, and the light LGT irradiates the first irradiation area 122 after being reflected by the reflector 142, and the driving module 144 drives the reflector 142 to be disposed at a second angle, so that the incident angle θ of the light LGT incident on the plane mirror is changed (see fig. 2 and 3A, the incident angle θ has different angles), and the angle of reflection of the light LGT on the reflector 142 is changed, so that the light LGT irradiates the second irradiation area 124 instead of the first irradiation area 122.

After the positions of the light source 160 and the optical component 120 are fixed, the designer of the distance measuring device 10 designs the mirror angle of the mirror 142 corresponding to the direction in which the light source 160 generates the light LGT and the positions of the first illumination area 122 and the second illumination area 124, and makes the driving module 144 drive the mirror 142 to perform two-stage adjustment so as to reflect the light LGT to illuminate the first illumination area 122 or the second illumination area 124 respectively.

In one embodiment, the driving module 144 drives the mirror 142 to adjust the mirror angle according to the switching command. The distance measuring device 10 may include an input device or be connected to an external input device, through which a user generates a switching command to control the driving module 144. Taking the input device as an example, when the user presses the key, the input device generates a switching command, and the driving module 144 receives the switching command and drives the mirror 142 to switch between the first angle and the second angle.

In another embodiment, the drive module 144 drives the mirror 142 to adjust the mirror angle multiple times in succession. In detail, when the distance measuring device 10 is started, the driving module 144 starts to continuously drive the mirror 142 to switch between the first angle and the second angle, and the light LGT irradiates the first irradiation region 122 or the second irradiation region 124 multiple times sequentially according to the adjustment of the mirror angle of the mirror 142. In addition, by adjusting the speed of the driving module 144 to drive the mirror 142 to adjust the mirror angle, the first illumination area 122 and the second illumination area 124 are both illuminated by the light LGT in a very short period of time, so as to generate an effect similar to that of simultaneously illuminating the first illumination area 122 and the second illumination area 124 with the light LGT.

In one embodiment, the drive module 144 may be, but is not limited to, a microelectromechanical system (Micro Electro Mechanical Systems, MEMS).

In an embodiment, in addition to the driving module 144 driving the mirror 142 to adjust the mirror angle, the reflecting module 140 may be fixed to adjust the angle of the light source 160 so that the light LGT irradiates the first irradiation area 122 or the second irradiation area 124, respectively. After the angle of the light LGT generated by the light source 160 is adjusted, the incident angle θ of the light LGT incident on the reflector 142 is also changed (see fig. 2 and 3B, where the incident angle θ has different angles), so as to change the angle of the light LGT reflected by the reflector 142, thereby changing the light LGT from irradiating the first irradiation region 122 to irradiating the second irradiation region 124.

In one embodiment, the first illumination area 122 and the second illumination area 124 of the optical device 120 may be implemented by measuring different distance diffractive optical elements (Diffractive Optical Element, DOE), for example, the first illumination area 122 is suitable for a diffractive optical element at a shorter distance, and the second illumination area 124 is suitable for a diffractive optical element at a longer distance. After the light LGT irradiates the first irradiation area 122 or the second irradiation area 124, the light LGT passes through the first irradiation area 122 or the second irradiation area 124 to generate diffraction phenomenon, so as to modulate the phase, amplitude and intensity of the light LGT to generate a first light spot or a second light spot on the projection plane 180.

Referring to fig. 4 to 7, fig. 4 is a schematic diagram of the distance measuring device of fig. 2 applied to a short distance measurement, fig. 5 is a schematic diagram of a first light spot according to an embodiment, fig. 6 is a schematic diagram of the distance measuring device of fig. 2 applied to a long distance measurement, and fig. 7 is a schematic diagram of a second light spot according to an embodiment. In one embodiment, the projection plane 180 is a surface of the distance measuring device 10 facing the object for distance measurement.

Taking the first illumination area 122 as a diffractive optical element suitable for a shorter distance and the second illumination area 124 as a diffractive optical element suitable for a longer distance as an example, the first light spot generated by the light LGT on the projection plane 180 after passing through the first illumination area 122 may be a random light spot, and the first illumination area 122 changes the phase and amplitude of the light LGT to form a random distribution or a light spot with complex characteristics; the second light spot generated by the light LGT passing through the second illumination area 124 on the projection plane 180 may be a regular light spot, and the second illumination area 124 changes the phase and amplitude of the light LGT to form a multi-point light spot or a geometric light spot with a certain arrangement mode.

In the distance measurement, the receiving module 200 can calculate the distance between the projection plane 180 and the distance measurement device 10 by analyzing the size, shape, brightness distribution or the relationship between the number of photons and time of the first light spot (random light spot) or the second light spot (regular light spot).

The receiving module 200 analyzes the first light spot or the second light spot refers to analyzing the reflected light reflected from the projection plane 180 by the first light spot or the second light spot. Specifically, the light LGT forms a first light spot or a second light spot on the projection plane 180 after being diffracted by the optical element 120, and the reflected light of the first light spot and the second light spot is received by the sensing element 240 of the receiving module 200.

Before the sensing element 240 receives the reflected light of the first light spot and the second light spot, the reflected light passes through the lens assembly 220, and the reflected light is focused by the lens assembly 220, so that the reflected light, which is originally scattered light, is focused on the sensing element 240. In addition to limiting the scattering of the reflected light, the lens assembly 220 can be more accurately received by the sensing element 240, and the spatial resolution of the distance measuring device 10 can be improved. Lens assembly 220 may be a single lens or may be composed of a plurality of lenses, and is not limited herein.

Referring to fig. 8, fig. 8 is a schematic diagram of a sensing component according to an embodiment. In an embodiment, the sensing device 240 includes a first sensor 242 and a second sensor 244 for measuring objects with different distances, and the first sensor 242 and the second sensor 244 have different sensing distances. Taking the first light spot as a random light spot and the second light spot as a regular light spot as an example, the first sensor 242 may be a sensor for measuring a short distance (for example, the sensing distance is between 0 and 1.5 meters), and the distance between the distance measuring device 10 and the closer projection plane 180 is obtained by the first sensor 242 receiving the reflected light of the first light spot reflected from the projection plane 180.

The second sensor 244 is a sensor for measuring a distance (for example, a sensing distance is between 1 and 8 meters), and the distance between the distance measuring device 10 and the farther projection plane 180 is obtained by the second sensor 244 receiving the reflected light of the second light spot reflected from the projection plane 180. That is, by integrating the first sensor 242 and the second sensor 244, the distance measuring device 10 can be used for measuring both short-range and long-range objects.

In one embodiment, the first sensor 242 has a measurement threshold, and the driving module 144 drives the mirror 142 to adjust the mirror angle when the sensing result of the first sensor 242 reaches or exceeds the measurement threshold. The sensing result refers to the distance between the distance measuring device 10 and the projection plane 180 calculated by the first sensor 242 according to the reflected light of the first light spot. The measurement threshold is related to the sensing distance of the first sensor 242, and the measurement threshold can be designed according to the sensitivity of the first sensor 242 and the second sensor 244 to the sensing distance.

Referring to the example that the sensing distance of the first sensor 242 is within 1.5 meters and the sensing distance of the second sensor 244 is between 1 and 8 meters, the surface (i.e. the projection plane 180) of the object located between 1 meter and 1.5 meters from the distance measuring device 10 is located in the measurable range of the first sensor 242 and the second sensor 244, and the value of the measurement threshold can be the value between 1 meter and 1.5 meters.

In this embodiment, if the accuracy of measuring the distance between the second sensor 244 and the object at a distance of 1 meter to 1.5 meters is greater than that of the first sensor 242, the value of the measurement threshold can be set to 1 meter. When the sensing result of the first sensor 242 is greater than or equal to 1 meter or the first sensor 242 cannot sense the distance between the distance measuring device 10 and the projection plane 180, the driving module 144 drives the mirror 142 to adjust the mirror angle until the light LGT irradiates the second irradiation area 124, until the sensing result of the first sensor 242 is less than 1 meter.

In one embodiment, the plurality of first sensors 242 may be, but are not limited to, infrared photodiodes (Infrared Photon Diode, IPRD). The infrared photodiode performs a trigonometric operation according to the captured infrared image and the reflected light of the first light spot (such as a random light spot) reflected by the projection plane 180 to obtain the sensing result.

In an embodiment, the plurality of second sensors 244 may be single photon avalanche diodes (Single Photon Avalanche Diode, SPAD) or current assisted photon regulators (Current Assisted Photonic Demodulator, CAPD) but are not limited thereto. The single photon avalanche diode calculates the time of flight of photons according to the reflected light of the second light spot (e.g. regular light spot) reflected by the projection plane 180 and the time point of the maximum number of photons, and further obtains the sensing result.

The number and arrangement of the first sensors 242 and the second sensors 244 are not limited, for example, the ratio of the number of the first sensors 242 to the number of the second sensors 244 in each column may be 1:1 and are staggered with respect to each other in the order of one first sensor 242, one second sensor 244; the ratio of the number of first sensors 242 to the number of second sensors 244 in each column may also be 3:1, and arranged in the order of three first sensors 242, one second sensor 244 (as shown in fig. 9); in addition, the first sensors 242 and the second sensors 244 may be arranged in a row (as shown in fig. 10). Furthermore, the number ratio of the first sensors 242 and the second sensors 244 in each row of the sensing element 240 is not necessarily the same, for example, one row of the sensing element 240 may be arranged in the order of three first sensors 242 and one second sensor 244, and the other row may be arranged in the order of all the first sensors 242 (as shown in fig. 9). It can be seen that the number and arrangement of the first and second sensors 242, 244 in the sensing assembly 240 can vary widely.

In one embodiment, the light source 160 may be a laser light source, an LED light source, a white light source, an infrared light source, etc.

In an embodiment, the collimator lens 170 may be a spherical lens, a cypress lens, an aspherical lens, a combination of the above lens types, or the like. The type of collimator 170 may depend on the wavelength of the light source 160, the beam diameter, the divergence, etc.

In summary, the distance measuring device 10 with the transmitting module 100 and the receiving module 200 can measure the distance between the device and the object, and the angle-adjustable reflecting module 140, the first sensor 242 and the second sensor 244 can greatly increase the distance range sensed by the distance measuring device 10, so as to cover both the distance measurement of the object at a relatively short distance and the distance measurement of the object at a relatively long distance.

Claims

1. A distance measuring device, comprising:

a transmitter module, comprising:

an optical assembly having a first illumination region and a second illumination region, the first illumination region and the second illumination region being adjacent to each other;

a reflection module, which makes a light ray irradiate the first irradiation area or the second irradiation area by the reflection of the reflection module; and

The light source is used for generating the light, the light generates a first light spot after passing through the first irradiation area, and the light generates a second light spot after passing through the second irradiation area; and

The receiving module is adjacent to the transmitting module and comprises a lens group and a sensing assembly, the sensing assembly comprises a plurality of first sensors and a plurality of second sensors, the first sensors receive reflected light of the first light spots reflected by a projection plane through the lens group, and the second sensors receive reflected light of the second light spots reflected by the projection plane through the lens group.

2. The distance measuring device according to claim 1, further comprising a collimator for collimating the light generated by the light source.

3. The distance measuring device according to claim 2, wherein the collimator is located between the light source and the reflection module.

4. The distance measuring device according to claim 2, wherein the collimator lens is located between the reflecting module and the optical component.

5. The distance measuring device according to claim 1, wherein the reflecting module comprises a mirror and a driving module, and the driving module drives the mirror to adjust a mirror angle so that the light beam is reflected by the mirror to irradiate the first irradiation area or the second irradiation area.

6. The distance measuring apparatus according to claim 5, wherein the driving module drives the mirror to adjust the mirror angle according to a switching command.

7. The distance measuring apparatus according to claim 5, wherein the driving module drives the mirror to adjust the mirror angle a plurality of times in succession.

8. The distance measuring apparatus according to claim 5, wherein the driving module drives the mirror to adjust the mirror angle according to a sensing result of the first sensors.

9. The distance measuring device according to claim 8, wherein the first sensors have a measurement threshold, and the driving module drives the mirror to adjust the mirror angle when the sensing result reaches or exceeds the measurement threshold.

10. The distance measuring device according to claim 1, wherein the first sensor and the second sensor are staggered with each other.