CN205091463U - Laser radar scans detecting device - Google Patents

Abstract

The utility model is applicable to the laser radar field, and provides a laser radar scanning detection device, which includes: a signal processing unit, a motor rotating platform, a laser and an image sensing unit, and the laser and the image sensing unit are fixed on the motor rotating platform , and in the same plane and keep a fixed distance, the emission direction of the laser has a fixed angle with the plane, the image sensing unit includes a horizontal sensor photosensitive sheet; the signal processing unit according to the imaging position, fixed distance, fixed angle and the image sensing unit The focal length calculates the distance of the detected object in the corresponding detection azimuth through the principle of triangulation, and generates a laser radar scanning information map according to the distance of the detected object and the corresponding azimuth information generated during the rotation process. The laser radar based on the triangular distance measurement of the utility model can meet omni-directional scanning detection and the detection accuracy in a short distance can reach millimeter level, and the requirements for laser power are low, and the system volume is small and the cost is low.

Description

A laser radar scanning detection device

technical field

The utility model belongs to the field of laser radar, in particular to a laser radar scanning detection device.

Background technique

Because of its ability to accurately measure the distance and azimuth information of the target position, lidar is more and more used in the defense industry and all aspects of smart life.

The commonly used detection methods of laser radar are pulse detection and phase detection. The pulse detection method is to receive a signal through APD after emitting a laser beam reflected by the target, and calculate the distance of the target according to the time difference between emission and reception. This method It is generally used for targets with a long range of action, which requires a high power laser and a high-cost APD detection array. The method based on phase detection is to calculate the distance information of the measured target according to the phase delay through signal modulation matching. This method has high detection accuracy, but it faces complex system debugging and high cost, and is suitable for the measurement of precision instruments. At the same time It cannot meet the requirements for high-speed acquisition of target data.

Utility model content

The purpose of the embodiments of the present invention is to provide a laser radar scanning detection device, aiming at solving the problems of high laser power requirement, slow acquisition speed and high cost in existing laser radar scanning.

The embodiment of the utility model is achieved in this way, a laser radar scanning detection device, the device includes:

A signal processing unit that records the azimuth information corresponding to the scanning detection of each emitted laser beam;

Under the control of the signal processing unit, a motor rotating platform that rotates horizontally and uniformly for one revolution from the initial orientation;

Under the control of the signal processing unit, emit a laser beam to scan and detect the laser for the object in front;

An image sensing unit that receives the laser beam reflected by the detected object and determines the imaging position (X) of the reflected laser beam on the photosensitive sheet of the sensor;

The laser and the image sensing unit are fixed on the motor rotating platform, the laser and the image sensing unit are on the same plane and keep a fixed distance (s), and the emission direction of the laser is in line with the plane With a fixed angle (β), the image sensing unit includes the sensor photosensitive sheet, the sensor photosensitive sheet is placed horizontally, the laser, the image sensing unit, and the motor rotating platform are all connected to the signal processing unit have an electrical connection;

The signal processing unit extracts the imaging position (X), and according to the imaging position (X), the fixed distance (s), the fixed angle (β) and the focal length (f) of the image sensing unit through a triangle The ranging principle calculates the distance (d) of the detected object in the corresponding detection azimuth, and generates a lidar scanning information map according to the distance (d) of one or more detected objects and the corresponding azimuth information generated during the rotation process.

Further, the laser is a red laser emitting a red laser beam, and the image sensing unit is a high-speed linear array CMOS image sensor;

The image sensing unit also includes:

When receiving the laser beam reflected by the object to be detected, the red light narrow-band filter that filters out the interference of external light sources and natural light;

A filter circuit that further filters out the clutter signal received on the photosensitive sheet of the sensor.

Furthermore, the image sensing unit also includes a pixel point on the photosensitive sheet of the sensor by sensing the reflection of the laser beam, and determines the position of the detected object according to the position of the voltage signal corresponding to the pixel point in the entire clock input signal. An imaging position determination module for the imaging position (X) on the photosensitive sheet of the sensor.

Furthermore, the formula for calculating the distance (d) of the detected object on the corresponding detection azimuth based on the triangulation ranging principle is:

$\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ;</span>$

Wherein, d is the distance between the detected object and the laser, f is the focal length of the image sensing unit, s is the fixed distance between the laser and the image sensing unit, and X is the detected object At the imaging position on the photosensitive sheet of the sensor, β is a fixed angle between the emission direction of the laser and the plane.

Furthermore, a photoelectric switch is set on the initial orientation, and the signal processing unit records the initial orientation information through the photoelectric switch and detects the corresponding orientation information each time the laser beam is emitted.

The lidar based on triangular ranging in the embodiment of the utility model can satisfy 360-degree azimuth scanning detection and the detection accuracy in a short distance can reach millimeter level, and at the same time meet the high-speed and intensive detection of target data at high scanning frequency, using the principle of triangulation And the linear array CMOS sensor accepts the signal, and the laser power requirement is low, and the system volume is small, and the cost is low.

Description of drawings

Fig. 1a is an external structure diagram of the laser radar scanning detection device provided by the embodiment of the present invention;

Fig. 1b is an internal structural diagram of the laser radar scanning detection device provided by the embodiment of the present invention;

Fig. 2 is a signal timing diagram of the image sensing unit provided by the embodiment of the utility model;

3 is a schematic diagram of the triangular ranging principle of the laser radar scanning detection method provided by the embodiment of the present invention;

Fig. 4 is a structural diagram of the image sensing unit in the lidar scanning detection device provided by the embodiment of the present invention.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute conflicts with each other.

The lidar based on triangular ranging in the embodiment of the utility model can satisfy 360-degree azimuth scanning detection and the detection accuracy in a short distance can reach millimeter level, and at the same time meet the high-speed and intensive detection of target data at high scanning frequency, using the principle of triangulation And the linear array CMOS sensor accepts the signal, and the laser power requirement is low, and the system volume is small, and the cost is low.

Fig. 1a and Fig. 1b respectively show the external structure and internal structure of the lidar scanning detection device provided by the embodiment of the present invention. For the convenience of description, only the parts related to the embodiment of the present invention are shown.

The laser radar scanning detection device can be used in the real-time positioning and map construction system of intelligent robots, including:

The laser 1 is used to emit a laser beam to scan and detect objects ahead under the control of the signal processing unit 4;

The image sensing unit 2 includes a sensor photosensitive sheet 21, which is used to receive the laser beam reflected by the detected object, and determine the imaging position (X) of the reflected laser beam on the sensor photosensitive sheet 21;

The motor rotating platform 3 is used to rotate horizontally and uniformly for one circle from the initial position under the control of the signal processing unit 4;

The laser 1 and the image sensing unit 2 are fixed on the motor rotating platform 3, the laser 1 and the image sensing unit 2 are in the same plane and keep a fixed distance (s), and the emission direction of the laser 1 has a fixed angle (β) with the above-mentioned plane , the sensor photosensitive sheet 21 is placed horizontally;

The signal processing unit 4 is used to record the orientation information corresponding to the scanning detection of each emitted laser beam, extract the imaging position (X), and according to the imaging position (X), fixed distance (s), fixed angle (β) and image transmission The focal length (f) of the sensing unit calculates the distance (d) of the detected object in the corresponding detection azimuth through the triangulation principle, and according to the distance (d) and the corresponding azimuth of one or more detected objects generated during the rotation process Information generation lidar scanning information map;

The laser 1 , the image sensing unit 2 , and the motor rotating platform 3 are all electrically connected to the signal processing unit 4 .

As an embodiment of the present invention, the laser 1 can use a red laser to emit a red laser beam, and the image sensing unit 2 can be realized by using a high-speed linear array CCD image sensor.

As an embodiment of the present utility model, referring to Fig. 4, the image sensing unit 2 includes:

The photosensitive sheet 21 of the sensor is used to receive the laser beam reflected by the detected object;

The red light narrowband filter 22 is used to filter out the interference of external light sources and natural light when receiving the laser beam reflected by the object to be detected. The red light narrowband filter 22 is located in front of the photosensitive sheet 21 of the sensor.

Filter circuit 23, for further filtering out the clutter signal received on the photosensitive sheet of the sensor;

The imaging position determination module 24 is used to detect the pixel points on the photosensitive sheet of the sensor reflected by the laser beam, and determine the imaging position (X) of the detected object on the photosensitive sheet of the sensor according to the position of the voltage signal corresponding to the pixel point in the entire clock input signal ;

The sensor photosensitive sheet 21 , the red light narrowband filter 22 , and the filter circuit 23 are all electrically connected to the imaging position determining module 24 .

As another embodiment of the present invention, a photoelectric switch can be set on the initial orientation, so that the signal processing unit can record the initial orientation information through the photoelectric switch and scan and detect the corresponding orientation information each time the laser beam is emitted.

The azimuth information refers to recording the azimuth corresponding to the laser every time a detection beam is sent during the rotation process. Sending the first detection beam corresponds to recording the initial azimuth, sending the second detection beam corresponds to recording the second azimuth, the system rotates and scans evenly, and there will be about 400 detection points in one rotation, so n detection points need to be recorded Corresponding orientation information.

In the embodiment of the present utility model, the laser 1 and the image sensing unit 2 are fixed on the motor rotating platform, and the sensor photosensitive sheet 21 is adjusted to a horizontal position, the system is powered on, and the signal processing unit 4 controls the motor rotating platform 3 to start smoothly. Rotate, the motor rotating platform 3 starts from the initial orientation of setting the photoelectric switch, the signal processing unit 4 records the position of the initial orientation θ=0, at the same time, the red laser 1 emits a red laser beam to detect the object in front of this orientation.

The red laser beam is captured by the sensitive high-speed linear array CCD image sensor 2 after being reflected by the detected object. The position of the signal occupying the entire clock input signal determines the imaging position (X) of the detected object on the photosensitive sheet of the sensor, as shown in FIG. 2 , and transmits the imaging position (X) to the signal processing unit 4 .

In the embodiment of the utility model, the high-speed linear array CCD image sensor is used in conjunction with the signal processing unit 4 to meet the overall rotation scanning requirements of the system, and its scanning frequency can reach 10 Hz, and 500 pixels can be collected for one week of scanning, that is, every second 5000 measurements.

Then, the distance of the detected object on the corresponding detection azimuth is calculated by the principle of triangulation ranging, combined with its schematic diagram 3, wherein, d is the distance between the detected object c and the laser 1, and f is the focal length of the image sensing unit 2, s is the fixed distance between the laser 1 and the image sensing unit 2, X is the imaging position of the detected object c on the photosensitive sheet of the sensor, and β is a fixed angle between the emission direction of the laser 1 and the above-mentioned plane;

Then, the triangle abc and the triangle egb are similar triangles, according to the principle that the corresponding sides or heights of similar triangles are proportional, q=fs/X, d=q/sin(β), therefore, the triangular ranging principle calculates the corresponding detection azimuth The distance (d) formula of the detected object is derived as:

$\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ;</span>$

In the above formula, X is the only variable to be measured, that is, the distance d is converted into the value X of the imaging red light point on the photosensitive sheet of the sensor after the measured object is irradiated by the laser, and this value can be determined by the high-speed linear array CCD image sensor It is calculated from the pixel position captured during scanning detection.

During the working process of the system, the motor rotating platform can run smoothly and rotate 360 degrees at a frequency of up to 10Hz, and the photoelectric switch set on the initial orientation can record the initial orientation of the rotating scan, and the signal processing unit can record each scan through the photoelectric switch. The orientation information of the detected object, combined with the number of points scanned in one circle, can accurately record the orientation information of each scanned point during the scanning process, that is, to realize the detection and scanning of the position of the entire measured space. information.

The signal processing unit 4 transmits the distance (d) of all surrounding measured objects and the corresponding orientation information θ=0 to the PC terminal system according to the detection rotation, and generates and draws the laser radar scanning information map through the PC terminal system, or through The signal processing unit 4 generates the laser radar scanning information, and then sends it to the display device to display the laser radar scanning information map.

The lidar based on triangular ranging in the embodiment of the utility model can satisfy 360-degree azimuth scanning detection and the detection accuracy in a short distance can reach millimeter level, and at the same time meet the high-speed and intensive detection of target data at high scanning frequency, using the principle of triangulation And the linear array CMOS sensor accepts the signal, and the laser power requirement is low, and the system volume is small, and the cost is low.

The above are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model should be included in the utility model. within the scope of protection.

Claims (5)

1. A laser radar scanning detection device is characterized in that the device comprises: A signal processing unit that records the azimuth information corresponding to the scanning detection of each emitted laser beam; Under the control of the signal processing unit, a motor rotating platform that rotates horizontally and uniformly for one revolution from the initial orientation; Under the control of the signal processing unit, emit a laser beam to scan and detect the laser for the object in front; An image sensing unit that receives the laser beam reflected by the detected object and determines the imaging position (X) of the reflected laser beam on the photosensitive sheet of the sensor; The laser and the image sensing unit are fixed on the motor rotating platform, the laser and the image sensing unit are on the same plane and keep a fixed distance (s), and the emission direction of the laser is in line with the plane With a fixed angle (β), the image sensing unit includes the sensor photosensitive sheet, the sensor photosensitive sheet is placed horizontally, the laser, the image sensing unit, and the motor rotating platform are all connected to the signal processing unit have an electrical connection; The signal processing unit extracts the imaging position (X), and according to the imaging position (X), the fixed distance (s), the fixed angle (β) and the focal length (f) of the image sensing unit through a triangle The principle of ranging calculates the distance (d) of the detected object in the corresponding detection azimuth, and generates a laser radar scanning information map according to the distance (d) of one or more detected objects and the corresponding azimuth information generated during the rotation process. 2. The device according to claim 1, wherein the laser is a red laser emitting a red laser beam, and the image sensing unit is a high-speed linear array CMOS image sensor; The image sensing unit also includes: When receiving the laser beam reflected by the object to be detected, the red light narrow-band filter that filters out the interference of external light sources and natural light; A filter circuit that further filters out the clutter signal received on the photosensitive sheet of the sensor. 3. The device according to claim 1, wherein the image sensing unit further comprises a pixel point on the photosensitive sheet of the sensor by sensing the reflection of the laser beam, and occupies the corresponding voltage signal according to the pixel point. The position of the entire clock input signal determines the imaging position determination module of the imaging position (X) of the detected object on the photosensitive sheet of the sensor. 4. The device according to claim 1, wherein the formula for calculating the distance (d) of the detected object on the corresponding detection azimuth according to the principle of triangulation is: Wherein, d is the distance between the detected object and the laser, f is the focal length of the image sensing unit, s is the fixed distance between the laser and the image sensing unit, and X is the detected object At the imaging position on the photosensitive sheet of the sensor, β is a fixed angle between the emission direction of the laser and the plane. 5. The device according to claim 1, characterized in that a photoelectric switch is set on the initial orientation, and the signal processing unit records the initial orientation information through the photoelectric switch and then scans and detects the corresponding laser beam each time. orientation information.