Laser ranging type edge finding sensor
By using one-dimensional optoelectronic devices and microprocessors to control the laser in the edge-to-survey sensor, the workpiece edge position signal is directly output, which solves the problems of low communication efficiency and data processing lag of existing ranging sensors, and achieves fast and accurate edge detection , reduces costs and improves production efficiency.
Patent Information
- Application Number
- CN202411594231.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-08
- Publication Date
- 2024-12-27
AI Technical Summary
The existing ranging sensors have problems such as low communication efficiency, lag in data processing and high cost in edge patrol applications, and cannot quickly capture the edge of the workpiece, affecting the edge patrol effect.
One-dimensional optoelectronic devices are used to convert the target distance change into analog or digital signals, and the edge position signal of the workpiece is directly output through circuit processing, simplifying the communication and calculation process between the upper computer and the sensor, and using a microprocessor to control the laser and edge circuit to achieve rapid hardware Identify and output edge signals.
It realizes fast and lag-free edge patrol sensors, saves the upper computer computing process and costs, improves production efficiency and intelligence, and has high cost performance and wide practicality.
Smart Images
Figure CN119197317A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a sensor, in particular to a laser ranging type edge patrol sensor. Background Art
[0002] Determining the edge position of a workpiece is a typical application requirement in many fields of the national economy. For example, before cutting a steel plate, it is necessary to determine the edge position of the steel plate to be cut in order to determine the moving range of the cutting head and avoid out-of-bounds waste. On the other hand, determining the edge position of the steel plate to be cut can also clarify the size and orientation of the steel plate to be cut, prevent deviations in the cutting direction, and improve the cutting processing accuracy and intelligence.
[0003] At present, there are many ways to detect the edge of a workpiece. Typical edge detection is to install multiple distance measuring sensors on the equipment to directly measure the edge distance of the workpiece, thereby determining the edge position and orientation of the workpiece. However, this method has obvious disadvantages: first, multiple sensors need to be arranged to realize workpiece positioning and orientation detection, which is costly and complex; second, the sensor can only be fixedly installed on the machine tool equipment, and can only detect the edge of the workpiece close to it, and cannot detect the edge of the workpiece far away from the sensor, which is more limited in use.
[0004] To this end, the industry has gradually proposed the concept of "edge patrol". That is, a distance sensor is directly installed on the tool head (such as a laser cutting head) and moves with the tool head. During the movement, the distance sensor continuously collects the distance between the tool head and the workpiece. When the edge of the workpiece is reached, the distance value changes rapidly, and the edge information can be obtained through data processing by the controller. The advantage of this method is that only one sensor is needed to realize the edge patrol function, which is the lowest cost and the simplest. There are also many kinds of distance sensors used, including laser sensors, capacitive sensors, inductive sensors, eddy current sensors, ultrasonic sensors, and photoelectric switches. Among them, laser distance sensors are the most suitable because of their advantages such as small photoelectricity, high precision, and fast speed.
[0005] However, there are some inherent problems and defects in using distance measuring sensors for edge patrol: first, the controller needs to continuously read the measurement values of the sensor. When the communication efficiency is low, the frequency of data collection will be too low, time will be delayed, and the edge of the workpiece cannot be captured quickly. Second, the host computer controller needs to process a large amount of data collected at high speed, and the edge information will inevitably be obtained through the algorithm. Due to the quality and efficiency of the algorithm, the actual edge patrol effect is greatly reduced. Summary of the invention
[0006] In view of the current situation that the existing distance measuring sensors cannot meet the requirements of edge patrol, the present invention proposes a laser distance measuring edge patrol sensor and a method thereof. The edge patrol sensor adopts a one-dimensional photoelectric device as the core, and directly converts the distance change of the target into an analog or digital signal output. When the edge position of the workpiece is reached, the distance between the sensor and the workpiece shows a rapid cliff-like drop. Through circuit processing, the edge position signal of the workpiece can be directly output. The edge patrol sensor eliminates the lag disadvantages of high-speed communication between the host computer and the sensor and the edge calculation of the host computer at one time, has the outstanding advantages of fast speed and no lag, and saves the calculation process and cost expenditure of the host computer, and has a very high cost performance. In addition, the edge patrol sensor of the present invention can still measure the distance value between the sensor and the workpiece, and can also be set according to the distance value, so as to adapt to the edge patrol requirements of workpieces of different heights. The edge patrol sensor not only has stable and reliable performance, compact size, but also convenient and quick assembly, can significantly improve production efficiency and intelligence, achieve low cost, high cost performance, and has wide practicality and versatility.
[0007] The present invention is achieved through the following technical solutions: The laser ranging type edge patrol sensor proposed in the present invention is characterized in that the sensor includes a laser, a filter, an imaging mirror, a photoelectric device, a front circuit, a control circuit, a display, and an edge circuit, wherein: The laser is an industrial-grade miniaturized laser, which can generate a laser beam required for measurement under the control of a control circuit, project it onto the surface of a workpiece and form a laser spot, and can also turn off the laser under the control of the control circuit; The filter is a narrow-band filter, the central wavelength of which is consistent with that of the laser, and is used to filter out interference from ambient light and improve anti-interference capability; The imaging mirror is a high-performance industrial-grade lens that images the laser spot on the surface of the workpiece onto the sensitive surface of the photoelectric device; The photoelectric device is a one-dimensional position sensitive device, which can receive the light beam from the imaging mirror and output an electrical signal related to the light beam irradiation position; The pre-circuit is used to pre-process the output electrical signal of the photoelectric device to improve the anti-interference ability; the electrical signal output by the photoelectric device is divided into two after passing through the pre-circuit: one path enters the control circuit to process and obtain the distance between the workpiece and the sensor; the other path enters the edge circuit to identify the presence of the workpiece edge through hardware processing; The control circuit is a measurement and control circuit with a microprocessor as the core, and has four aspects of work: first, it controls the laser to emit or turn off the laser as needed; second, it receives the electrical signal from the front circuit to obtain the distance between the sensor and the surface of the workpiece; third, it sets the edge circuit to adapt to the height changes of different workpieces and different drop amplitude requirements; fourth, it receives instructions from the host computer and performs related operations on the sensor; The display is an industrial-grade digital display that can display the sensor's working status and related information; The edge circuit directly collects the output electrical signal of the front circuit, identifies the cliff-like drop characteristics of the workpiece surface through hardware processing, thereby obtaining the edge signal of the workpiece and directly outputting it to the host computer; in addition, the edge circuit can accept the threshold setting from the control circuit to adapt to different workpiece height changes and different drop amplitude requirements.
[0008] The working process of the laser ranging edge patrol sensor of the present invention is as follows: the laser beam emitted by the laser is projected onto the surface of the workpiece and forms a laser spot, which is imaged onto the sensitive surface of the photoelectric device by the imaging mirror. After the electrical signal output by the photoelectric device passes through the front circuit, it is divided into two: one path enters the control circuit, which is used to process and obtain the distance between the workpiece and the sensor, and display it through the display; the other path enters the edge circuit, and through hardware processing, identifies the appearance of the edge of the workpiece. In the process of the cutting head driving the edge patrol sensor to move, if the laser spot is always in the surface area of the workpiece, the control circuit continuously obtains the distance value between the sensor and the workpiece, and displays the distance value through the display, and the edge circuit does not have any signal output. When the laser spot reaches the edge of the workpiece, the edge circuit immediately recognizes the cliff-like drop feature, and then quickly outputs the edge signal to the host computer.
[0009] The laser ranging edge patrol sensor of the present invention is also characterized in that the edge circuit is composed of a differential circuit, a filter circuit, a threshold circuit, a shaping circuit, a communication circuit, and a power supply circuit; the differential circuit is used to differentiate the electrical signal representing the distance of the workpiece surface from the front circuit to identify the cliff-like drop characteristics generated by the edge of the workpiece; the filter circuit is used to filter out the small fluctuations of the differential signal to overcome the small jitter caused by the uneven surface of the workpiece; the threshold circuit is used to select the amplitude threshold of the output edge signal according to the set parameters of the control circuit to enhance the intelligence and versatility of the edge patrol; the shaping circuit is used to shape the electrical signal passing through the threshold circuit to meet the requirements of standard communication; the communication circuit is used for the interface between the edge circuit and the host computer to transmit the edge signal; the power supply circuit provides energy and level reference for all circuits.
[0010] The present invention proposes a method for extracting edge signals based on the above-mentioned laser ranging type edge patrol sensor, which is specifically as follows: (1) Turn on the laser, project the laser onto the workpiece surface and form a light spot, which is then projected onto the sensitive surface of the optoelectronic device through the imaging mirror; (2) The photoelectric device generates an electrical signal related to the position of the light spot and sends it to the front-end circuit; (3) The electrical signal generated by the front-end circuit is split into two, one is sent to the control circuit, and the other is sent to the edge circuit; (4) The control circuit processes the electrical signal from the front circuit, obtains the distance value between the sensor and the workpiece, and sends it to the display for display; (5) The edge circuit performs differential processing on the electrical signal from the front circuit. When it is found that the distance has a cliff-like drop or rise when reaching the edge, the differential circuit automatically generates a pulse signal, which is shaped by the shaping circuit and then automatically sends the edge signal to the upper computer; (6) The host computer can send setting instructions such as working distance and drop amplitude to the control circuit; (7) After receiving the command from the host computer, the control circuit sends a threshold signal to the edge circuit, thereby adjusting the threshold level to suppress the interference of small fluctuations and noise. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a schematic diagram of the composition of the laser ranging type edge patrol sensor of the present invention.
[0012] Figure 2 The diagram is a schematic diagram of the principle composition of the edge circuit of the laser ranging edge patrol sensor of the present invention.
[0013] Figure 3 The figure is a schematic diagram of the differential circuit principle composition of the laser ranging edge patrol sensor of the present invention.
[0014] In the figure, 1-laser, 2-filter, 3-imaging mirror, 4-photoelectric device, 5-front circuit, 6-control circuit, 7-display, 8-edge circuit, 9-workpiece, 10-host computer. DETAILED DESCRIPTION
[0015] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiment. The present invention is achieved through the following technical solutions: The laser ranging type edge patrol sensor proposed in the present invention is characterized in that the sensor includes a laser 1, a filter 2, an imaging mirror 3, a photoelectric device 4, a front circuit 5, a control circuit 6, a display 7, and an edge circuit 8. Figure 1 As shown, where: The laser 1 is an industrial-grade miniaturized laser, such as a laser diode, which can generate a laser beam required for measurement under the control of a control circuit 6, project it onto the surface of a workpiece 9 and form a laser spot, and can also turn off the laser under the control of the control circuit 6; The filter 2 is a narrow-band filter, the central wavelength of which is consistent with that of the laser 1, and is used to filter out interference from ambient light and improve anti-interference capability; for example, assuming that the wavelength of the laser 1 is 650nm, the central wavelength of the filter 2 may be 650nm; The imaging mirror 3 is a high-performance industrial-grade lens, such as a single-piece aspherical optical lens, which images the laser spot on the surface of the workpiece 9 onto the sensitive surface of the photoelectric device 4; The optoelectronic device 4 is a one-dimensional position sensitive device, such as a linear array CCD, a linear array CMOS, a one-dimensional PSD, etc., which can receive the light beam from the imaging mirror 3 and output an electrical signal related to the light beam irradiation position; The pre-circuit 5 is used to pre-process the output electrical signal of the photoelectric device 4 to improve the anti-interference ability; the electrical signal output by the photoelectric device 4 is divided into two after passing through the pre-circuit 5: one path enters the control circuit 6 for processing to obtain the distance between the workpiece 9 and the sensor; the other path enters the edge circuit 8 to identify the edge of the workpiece 9 through hardware processing; The control circuit 6 is a measurement and control circuit with a microprocessor as the core, for example, it is built based on ARM, and has four aspects of work: first, it controls the laser 1 to emit or turn off the laser as needed; second, it receives the electrical signal from the front circuit 5 to obtain the distance between the sensor and the surface of the workpiece 9; third, it sets the edge circuit 8 to adapt to the height changes of different workpieces 9 and different drop amplitude requirements; fourth, it receives instructions from the host computer 10 to perform related operations on the sensor; The display 7 is an industrial-grade digital display, such as a digital tube, an OLED display, etc., which can display the working status of the sensor and related information; The edge circuit 8 directly collects the output electrical signal of the front circuit 5, identifies the cliff-like drop characteristics on the surface of the workpiece 9 through hardware processing, thereby obtaining the edge signal of the workpiece 9, and directly outputs it to the host computer 10; in addition, the edge circuit 8 can accept the threshold setting from the control circuit 6 to adapt to the height changes of different workpieces 9 and different drop amplitude requirements.
[0016] The working process of the laser ranging edge patrol sensor of the present invention is as follows: the laser beam emitted by the laser 1 is projected onto the surface of the workpiece 9 and forms a laser spot, which is imaged by the imaging mirror 3 onto the sensitive surface of the photoelectric device 4. After the electrical signal output by the photoelectric device 4 passes through the pre-circuit 5, it is divided into two: one path enters the control circuit 6 for processing to obtain the distance between the workpiece 9 and the sensor, and displays it through the display 7; the other path enters the edge circuit 8, and through hardware processing, identifies the appearance of the edge of the workpiece 9. In the process of the cutting head driving the edge patrol sensor to move, if the laser spot is always in the surface area of the workpiece 9, the control circuit 6 continuously obtains the distance value between the sensor and the workpiece 9, and displays the distance value through the display 7, while the edge circuit 8 does not have any signal output. When the laser spot reaches the edge of the workpiece 9, the edge circuit 8 immediately recognizes the cliff-like drop feature, and then quickly outputs the edge signal to the host computer 10.
[0017] The laser ranging type edge patrol sensor of the present invention is also characterized in that the edge circuit 8 is composed of a differential circuit 8a, a filter circuit 8b, a threshold circuit 8c, a shaping circuit 8d, a communication circuit 8e, and a power supply circuit 8f. Figure 2 The differential circuit 8a is used to perform differential calculation on the electrical signal representing the distance from the surface of the workpiece 9 from the front circuit 5 to identify the cliff-like drop characteristics generated by the edge of the workpiece, such as Figure 3 As shown; the filter circuit 8b is used to filter out the small fluctuations of the differential signal to overcome the small jitter caused by the uneven surface of the workpiece 9; the threshold circuit 8c is used to select the amplitude threshold of the output edge signal according to the set parameters of the control circuit 6, so as to enhance the intelligence and versatility of the edge patrol; the shaping circuit 8d is used to shape the electrical signal passing through the threshold circuit 8c, so as to meet the requirements of standard communication; the communication circuit 8e is used for the interface between the edge circuit 8 and the host computer 10 to transmit the edge signal; the power supply circuit 8f provides energy and level reference for all circuits.
[0018] The present invention proposes a data processing method based on the above-mentioned laser ranging type edge patrol sensor, which is specifically as follows: (1) Turn on the laser 1, project the laser onto the surface of the workpiece 9 and form a light spot, which is then projected onto the sensitive surface of the photoelectric device 4 through the imaging mirror 3; (2) The photoelectric device 4 generates an electrical signal related to the position of the light spot and sends it to the front circuit 5; (3) The electrical signal generated by the front circuit 5 is divided into two, one is sent to the control circuit 6, and the other is sent to the edge circuit 8; (4) The control circuit 6 processes the electrical signal from the front circuit 5, obtains the distance value between the sensor and the workpiece 9, and sends it to the display 7 for display; (5) The edge circuit 8 performs differential processing on the electrical signal from the front circuit 5. When it is found that the distance has a cliff-like drop or rise characteristic when reaching the edge, the differential circuit 8a automatically generates a pulse signal, which is automatically sent to the upper computer 10 after being shaped by the shaping circuit 8d; (6) The host computer 10 can send setting instructions such as working distance and drop amplitude to the control circuit 6; (7) After receiving the instruction from the host computer 10, the control circuit 6 sends a threshold signal to the edge circuit 8, thereby adjusting the threshold level to suppress the interference of small fluctuations and noise. Compared with the prior art, the laser ranging type edge patrol sensor of the present invention has the following beneficial effects: (1) The laser ranging edge patrol sensor of the present invention can obtain the edge signal of the workpiece through hardware without the need for host computer processing and calculation, which greatly saves communication time and calculation consumption and has excellent performance; (2) The laser ranging edge patrol sensor of the present invention adopts a dedicated edge circuit to directly process the electrical signal from the photoelectric device. It does not require control circuit calculation and processing. It directly generates the workpiece edge signal through hardware and outputs it directly to the host computer through a separate communication interface, thereby ensuring the accuracy and timeliness of the edge signal to the greatest extent.
[0019] (3) The laser ranging edge patrol sensor of the present invention can set the edge circuit through the control circuit, including parameters such as working distance and drop amplitude, so that the edge patrol sensor has good programmable performance and intelligence, good versatility, and wide application value. It can be seen that the technical solution of the present invention has very outstanding technical advantages and progress compared with traditional laser displacement sensors.
Claims
1. A laser ranging type edge patrol sensor, characterized in that: The sensor includes a laser, a filter, an imaging mirror, a photoelectric device, a front circuit, a control circuit, a display, and an edge circuit, wherein: The laser is an industrial-grade miniaturized laser, which can generate the laser beam required for measurement under the control of the control circuit, and can also turn off the laser under the control of the control circuit; The filter is a narrow-band filter, and the central wavelength is consistent with the laser; The imaging mirror is a high-performance industrial-grade lens that can image the laser spot onto the sensitive surface of the optoelectronic device; The photoelectric device is a one-dimensional position sensitive device, which can receive the light beam from the imaging mirror and output an electrical signal related to the light beam irradiation position; The pre-circuit is used to pre-process the output electrical signal of the photoelectric device. After passing through the pre-circuit, the signal is divided into two parts: one part enters the control circuit to process and obtain the distance between the workpiece and the sensor; the other part enters the edge circuit to identify the presence of the workpiece edge through hardware processing. The control circuit is a measurement and control circuit with a microprocessor as the core, and has four aspects of work: first, it controls the laser to emit or turn off the laser as needed; second, it receives the electrical signal from the front circuit to obtain the distance between the sensor and the surface of the workpiece; third, it sets the edge circuit to adapt to the height changes of different workpieces and different drop amplitude requirements; fourth, it receives instructions from the host computer and performs related operations on the sensor; The display is an industrial-grade digital display, which is used to display the working status of the sensor and related information; The edge circuit directly collects the output electrical signal of the front circuit, identifies the cliff-like drop or rise characteristics of the workpiece surface through hardware processing, thereby obtaining the edge signal of the workpiece and directly outputting it to the host computer; the edge circuit can accept the threshold setting from the control circuit to adapt to different workpiece height changes and different drop amplitude requirements.
2. The laser ranging type edge patrol sensor according to claim 1 is also characterized in that: The edge circuit is composed of several units including a differential circuit, a filter circuit, a threshold circuit, a shaping circuit, a communication circuit, and a power supply circuit, wherein: The differential circuit is used to perform differential calculation on the electrical signal representing the distance from the workpiece surface from the front circuit, so as to identify the cliff-like drop feature generated by the edge of the workpiece; The filter circuit is used to filter out the small fluctuation of the differential signal and overcome the small jitter caused by the uneven surface of the workpiece; the threshold circuit is used to select the amplitude threshold of the output edge signal according to the set parameters of the control circuit; The shaping circuit is used to shape the electrical signal passing through the threshold circuit so as to meet the requirements of standard communication; The communication circuit is used as an interface for transmitting edge signals between the edge circuit and the host computer; The power circuit provides energy and voltage level reference for all circuits.
3. The present invention proposes an edge signal processing method according to any one of claims 1 to 2, which is specifically as follows: (1) Turn on the laser, project the laser onto the workpiece surface and form a light spot, which is then projected onto the sensitive surface of the optoelectronic device through the imaging mirror; (2) The photoelectric device generates an electrical signal related to the position of the light spot and sends it to the front-end circuit; (3) The electrical signal generated by the front-end circuit is split into two, one is sent to the control circuit, and the other is sent to the edge circuit; (4) The control circuit processes the electrical signal from the front circuit, obtains the distance value between the sensor and the workpiece, and sends it to the display for display; (5) The edge circuit performs differential processing on the electrical signal from the front circuit. When it is found that the distance has a cliff-like drop or rise when reaching the edge, the differential circuit automatically generates a pulse signal, which is shaped by the shaping circuit and then automatically sends the edge signal to the upper computer; (6) The host computer can send setting instructions such as working distance and drop amplitude to the control circuit; (7) After receiving the instruction from the host computer, the control circuit sends a threshold signal to the edge circuit, thereby adjusting the threshold level to suppress the interference of small fluctuations and noise.