A multi-directional obstacle detection device

Abstract

The present invention discloses a multi-directional obstacle detection device, including a circuit board assembly, a light shield assembly, and a base. The circuit board assembly includes a first infrared emitting tube and a first infrared receiving head which are evenly spaced along the circumference of a horizontal plane, and a second infrared emitting tube and a second infrared receiving head which are arranged in an upward direction, as well as a main control chip, a power module, an infrared emitting tube power adjustment module, a power fine-tuning module, a carrier drive module, and an output module. The light shield assembly is mounted on the upper part of the circuit board assembly to optically isolate all infrared receiving heads inside the light shield assembly. The light shield assembly, the circuit board assembly, and the base are fixedly connected by screws. The present invention can simultaneously realize the measurement of the distance values ​​of obstacles in front, back, left, right, left front, left rear, right front, right rear, and above, and has a fast measurement speed, a small size, a light weight, and a low cost. It is particularly suitable for use in flying sports equipment that requires rapid movement and frequently changes the direction of movement.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a multi-directional obstacle detection device. The present invention can also be used in other circuits including mobile devices and intelligent controls, such as a remote control receiving circuit, or any circuit with obstacle detection requirements. Background Art

[0002] In real life, more and more smart devices need to detect the distance between the device and obstacles to facilitate automatic control such as route planning and obstacle avoidance. Obstacle detection has been widely used in drones, sweeping robots, driverless cars, etc. Especially on small multi-axis aircraft, a device with light weight, fast distance measurement speed, low power consumption and the ability to detect distances in multiple directions such as front, back, left and right is required. This ensures the automatic obstacle avoidance flight of the quadcopter, improves the safety of the multi-axis aircraft itself, and prevents safety accidents caused by multi-axis aircraft injuring people.

[0003] Common obstacle detection methods on the market include laser ranging, ultrasonic ranging, and image recognition (vision) ranging. However, common obstacle detection methods and equipment often have the disadvantages of high cost, high power consumption, slow distance measurement speed, and large weight and volume. At the same time, because of the above reasons, common obstacle detection devices can generally only detect obstacles in one direction at the same time. It is impossible to simply increase the number of detection devices to simultaneously complete obstacle detection in multiple directions such as front, back, left, and right. This is not conducive to use on multi-axis aircraft that need to move forward, backward, left, and right.

[0004] Therefore, we propose a multi-directional obstacle detection device to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-directional obstacle avoidance distance sensor to solve the problems of high cost, high power consumption, slow distance measurement speed, large weight and volume, and inability to simultaneously complete obstacle detection in multiple directions such as front, back, left, and right.

[0006] In order to solve the above technical problems, the present invention is implemented through the following technical solutions: A multi-directional obstacle detection device, including a circuit board assembly, a light shield assembly and a base. The circuit board assembly includes infrared emitting tubes distributed at equal intervals along a horizontal circumference, infrared receiving heads distributed at equal intervals along a horizontal circumference, infrared emitting tubes arranged in an upward direction, infrared receiving heads arranged in an upward direction, a main control chip, a power module, an infrared emitting tube power adjustment module, a power fine-tuning module, a carrier drive module and an output module. The light shield assembly is mounted on the upper part of the circuit board assembly to optically isolate all infrared receiving heads inside the light shield assembly to prevent infrared signals reflected by non-obstacles from being transmitted to the infrared receiving heads. The light shield body is provided with infrared emitting windows of the infrared emitting tubes and infrared receiving windows of the infrared receiving heads at equal intervals outwardly along the horizontal circumference. The light shield assembly includes a light shield body, an upper infrared receiving head mounting seat and an upper cover plate, wherein the upper infrared receiving head mounting seat is located at the upper central position of the light shield body and is bonded to the light shield body, and the upper cover plate is located at the middle position of the upper infrared receiving head mounting seat and is bonded to the upper infrared receiving head mounting seat. The base is located below the circuit board assembly, and the light shield assembly, the circuit board assembly and the base are fixedly connected by screws.

[0007] Preferably, the number of infrared emitting tubes and infrared receiving heads evenly distributed along the horizontal circumference is 8 each, which are arranged in front, back, left, right, left front, left back, right front and right back. Combined with the emitting angle of the infrared emitting tube and the receiving angle of the infrared receiving head, obstacle detection in multiple directions of front, back, left, right, left front, left back, right front and right back can be completed.

[0008] Preferably, a groove with a shape similar to that of the infrared receiving head is opened at the lower part of the shading cover body, and the groove can accommodate the infrared receiving head so that each infrared receiving head is optically isolated from each other, and at the same time, the shading cover body can be easily installed on the outside of the infrared receiving head.

[0009] Preferably, the sunshade assembly is made of opaque dark-colored plastic material.

[0010] Preferably, the circuit board assembly is circular with a diameter of 40-60 mm.

[0011] A multi-directional obstacle detection device, the principle of which is to measure the distance: whether the infrared receiving head can receive the carrier infrared signal emitted by the infrared transmitting tube reflected by the obstacle is related to both the distance between the obstacle's reflective surface and the infrared receiving head and the intensity of the infrared signal emitted by the infrared transmitting tube. When the distance between the obstacle's reflective surface and the infrared receiving head is a fixed value, the transmission power of the infrared signal emitted by the infrared transmitting tube is adjusted in a step-by-step manner from small to large through the main control chip of the circuit board assembly and the infrared transmitting tube power adjustment module. At the beginning, due to the small transmission power of the infrared signal, the intensity of the infrared signal is too small, and the infrared receiving head cannot receive the infrared signal reflected back by the reflecting surface. As the transmission power of the infrared signal increases, when the intensity of the emitted infrared signal increases to a certain value, the infrared receiving head begins to be able to receive the infrared signal reflected back by the reflecting surface, and the intensity value of the infrared signal at this time corresponds to the distance value between the reflecting surface and the infrared receiving head. Similarly, when the intensity of the carrier infrared signal emitted by the infrared transmitting tube is a fixed value, the reflecting surface approaches the infrared receiving head from a far distance. At the beginning, the infrared signal intensity is too small due to the distance of the reflective surface. The infrared receiving head cannot receive the infrared signal reflected by the reflective surface. When the reflective surface approaches the infrared receiving head from a distance to a certain distance value, the infrared receiving head can begin to receive the infrared signal reflected by the reflective surface. At this time, the distance value between the reflective surface and the infrared receiving head corresponds to the intensity value of the infrared signal. According to the correspondence between the distance value between the reflective surface and the infrared receiving head and the intensity value of the infrared signal, a corresponding relationship table between the intensity value of the transmitted signal and the distance value is established. The distance value can be calculated by the intensity value of the infrared signal transmitted when the reflected signal is received. Under normal circumstances, the greater the voltage applied to the two ends of the infrared transmitting tube, the greater the current flowing through the infrared transmitting tube, the greater the transmitting power of the infrared transmitting tube and the intensity of the infrared signal emitted by the infrared transmitting tube, so the voltage at the two ends of the infrared transmitting tube can also be used to represent the transmitting power of the infrared transmitting tube and the intensity of the infrared signal emitted by the infrared transmitting tube.

[0012] Although the accuracy of distance measurement using the above method is not high, with an error of 5 cm to 30 cm depending on the algorithm, it is accurate enough for obstacle detection.

[0013] Under the control of the main control chip, the infrared transmitting tube power adjustment module of the circuit board assembly quickly and continuously adjusts the working voltage of the infrared transmitting tube to change the intensity of the emitted infrared signal. At the same time, the main control chip continuously and synchronously determines whether each infrared receiving head receives the reflected infrared light, and records and analyzes the working voltage value of the infrared transmitting tube when each infrared receiving head just receives the reflected signal. The distance between the obstacle and each infrared receiving head is determined based on the corresponding relationship table between the working voltage value of the infrared transmitting tube and the distance value.

[0014] Preferably, the infrared emitting tube power adjustment module adopts the DAC output module and output follower mode of the main control chip to adjust the intensity value of the infrared emitting signal by changing the working voltage of the infrared emitting tube. At this time, the control value of the DAC module of the main control chip corresponds to the intensity value of the emission signal of the infrared emitting tube.

[0015] Preferably, the transmitting signal of the infrared transmitting tube adopts a carrier frequency of 38KHz to improve the anti-interference ability to the infrared clutter of the surrounding environment.

[0016] Preferably, the infrared receiving head adopts an integrated infrared receiving head of an infrared remote controller with a center frequency of 38KHz commonly used in the market, so as to improve the anti-interference ability and reduce the product cost.

[0017] Preferably, the period T of the main control chip measuring 9 infrared signals simultaneously is 0.1 second, and 10 groups of distance values ​​in 9 directions can be obtained in one second.

[0018] The term "infrared receiver head", also known as an infrared receiver module or infrared receiver module (Infrared Receiver Module, IRM for short), refers to an integrated infrared receiver head that integrates infrared monitoring diodes, amplifiers, limiters, bandpass filters, integrator circuits, comparators and other circuits into one component and combines and packages them together, which can simplify and miniaturize the circuit design of application products. The integrated infrared receiver head will output a low-level signal when it receives an infrared carrier signal of sufficient strength and the carrier frequency meets the requirements of the infrared receiver head, otherwise it will output a high-level signal. The integrated infrared receiver head is widely used in infrared remote control fields such as air conditioners, fans, heaters, humidifiers, televisions, DVDs, set-top boxes, remote-controlled toys, and lighting.

[0019] The term "DAC" refers to digital-to-analog converter, also known as D / A converter, or DAC for short. It is a device that converts digital quantities into analog quantities. Currently, commonly used single-chip microcomputers, signal processors and other main control chips have integrated digital-to-analog converters.

[0020] The term "DAC control value" refers to the value of the digital quantity when the digital-to-analog converter converts the digital quantity into the analog quantity when working.

[0021] The term "PWM" refers to the pulse width modulation (PWM) technology, which uses a pulse train with equal pulse width as a PWM waveform. By changing the period of the pulse train, the frequency can be modulated, and by changing the width or duty cycle of the pulse, the voltage can be adjusted. By adopting an appropriate control method, the voltage and frequency can be coordinated. In this embodiment, an intermittent square wave voltage signal with a frequency of 38KHz is generated by changing the period of the pulse train. The pulse width modulator is integrated in the main control chip such as the commonly used single-chip microcomputer and signal processor.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The multi-directional obstacle detection device can simultaneously measure the distance values ​​of obstacles in front, behind, left, right, left front, left rear, right front, right rear and above, and has a fast measurement speed. It is particularly suitable for sports equipment that requires fast movement and frequently changes movement direction.

[0024] 2. The multi-directional obstacle detection device is small in size, light in weight, and has low power consumption. It is particularly suitable for use in flying sports equipment that is sensitive to weight and power consumption.

[0025] 3. The multi-directional obstacle detection device uses commonly used infrared transmitting tubes, infrared receiving heads and other cheap components combined with special algorithms to measure distance, which simplifies the circuit, reduces costs, and is easy to promote and use in the toy drone market where the sales price is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In the drawings, throughout the various figures, the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

[0027] Figure 1 It is a schematic diagram of the front cross-sectional structure of the present invention.

[0028] Figure 2 It is a schematic diagram of the three-dimensional structure of the present invention.

[0029] Figure 3 This is a schematic diagram of the three-dimensional structure of the present invention after the sunshade component is removed.

[0030] Figure 4 This is a schematic diagram of the three-dimensional structure of the present invention after removing the base and part of the circuit board components.

[0031] Figure 5 It is a schematic diagram of the three-dimensional assembly relationship in one direction of the present invention.

[0032] Figure 6 It is a schematic diagram of the three-dimensional assembly relationship in another direction of the present invention.

[0033] Figure 7 It is a circuit schematic diagram of the present invention. Figure 7 Mid-infrared emitting tubes LED1-LED8 correspond to Figure 1 —6, the infrared transmitting tubes 1 are evenly spaced along the horizontal circumference, and the infrared receiving heads WH1—WH8 correspond to Figure 1 —6, the infrared receiving heads 2 are evenly spaced along the horizontal circumference, and the infrared transmitting tubes LED9 correspond to Figure 1 —6, the infrared transmitting tube 3 arranged upward, the infrared receiving head WH9 corresponds to Figure 1 —6, an infrared receiving head 4 arranged in an upward direction.

[0034] Figure 8 It is a flow chart of the program of the present invention.

[0035] Fig. 9 It is a waveform diagram showing the variation of the emission intensity of the infrared emitting tube of the present invention. Fig. 9 The V_LED voltage value and the number of steps in the figure can help to understand the change of V_LED voltage, but in actual application, the V_LED voltage value and the number of steps will change according to the usage requirements and device performance.

[0036] Fig.10 This is a waveform diagram of the present invention when the distance between the obstacle and the infrared receiving head is 1.7 meters.

[0037] Fig.11 This is a waveform diagram of the present invention when the distance between the obstacle and the infrared receiving head is 0.7 meters.

[0038] Fig.12 The corresponding relationship diagram of the DAC control value, V_LED voltage, direction x register value and distance value of a main control chip of the present invention is provided. The corresponding relationship diagram of the DAC control value, V_LED voltage, direction x register value and distance value of the main control chip can help understand how to obtain the distance value through the DAC control value, V_LED voltage and direction x register value, but the DAC control value, V_LED voltage value, direction x register value and distance value in the corresponding relationship diagram will change according to different usage requirements and device performance in actual applications.

[0039] In the figure: 1. Infrared emitting tubes distributed at equal intervals along a horizontal circle; 2. Infrared receiving heads distributed at equal intervals along a horizontal circle; 3. Infrared emitting tubes emitting upward; 4. Infrared receiving head receiving upward; 5. Circuit board assembly; 6. Light shield body; 7. Upper infrared receiving head mounting base; 8. Upper cover; 9. Base; 10. Screws; 11. Infrared receiving window; 12. Infrared emitting window; 13. Infrared receiving window facing upward; 14. Infrared emitting window facing upward; 15. Infrared receiving head groove. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] See also Figure 1 —12, the present invention provides a technical solution: a multi-directional obstacle detection device, including a circuit board assembly 5, a light shield assembly and a base 9. The circuit board assembly 5 includes infrared emitting tubes 1 distributed at equal intervals along a horizontal circumference, infrared receiving heads 2 distributed at equal intervals along a horizontal circumference, infrared emitting tubes 3 emitting upward, infrared receiving heads 4 receiving upward, a main control chip, a power module, an infrared emitting tube power adjustment module, a power fine-tuning module, a carrier drive module and an output module. The light shield assembly includes a light shield body 6, an upper infrared receiving head mounting seat 7 and an upper cover plate 8. The upper infrared receiving head mounting seat 7 is located at the upper central position of the light shield body 6 and is connected to the light shield body 6 by adhesive bonding. The purpose of the infrared receiving head mounting seat 7 and the light shield body 6 being separated is to facilitate the installation of the infrared emitting tubes 1 distributed at equal intervals along the horizontal circumference into the infrared emitting window 12; the upper cover plate 8 is located at the middle position of the upper part of the upper infrared receiving head mounting seat 7 and is connected to the upper infrared receiving head mounting seat 7 by adhesive bonding; the upper part of the upper infrared receiving head mounting seat 7 is provided with an upward infrared emitting window 14, and the upper part of the upper cover plate 8 is provided with an upward infrared receiving window 13. The light shield assembly is mounted on the upper part of the circuit board assembly 5, and all infrared receiving heads are optically isolated inside the light shield assembly to prevent the infrared signal reflected by non-obstacles from being transmitted to the infrared receiving head. The base 9 is located below the circuit board assembly. The light shield body 6, the circuit board assembly 5 and the base 9 are fixedly connected by screws 10.

[0042] like Figure 3 The circuit board assembly 5 is circular, with a diameter of 40-60 mm.

[0043] like Figure 3The number of the infrared emitting tubes 1 and the infrared receiving heads 2 distributed at equal intervals along the horizontal circumference is 8, arranged in front, back, left, right, left front, left back, right front, and right back. The infrared emitting and infrared receiving faces face outward, and the combination of the emitting angle of the infrared emitting tube and the receiving angle of the infrared receiving head can realize the detection of obstacles without blind spots in the horizontal plane within a range of 360 degrees. However, the number of these infrared emitting tubes 1 and infrared receiving heads 2 can be changed to provide unique benefits for any specific situation, or to meet the specific design requirements of various embodiments. For example, in applications that do not require the detection of obstacles without blind spots in the horizontal plane within a range of 360 degrees, only the infrared emitting tubes 1 and infrared receiving heads 2 arranged in the front, back, left, and right directions may be required; in applications that do not require the detection of obstacles behind the horizontal plane, the infrared emitting tubes 1 and infrared receiving heads 2 arranged in the back, left back, and right back directions may be omitted. In addition, although the number of infrared emitting tubes 1 and infrared receiving heads 2 in this embodiment is 8 each, it should be understood that the number of infrared emitting tubes 1 and infrared receiving heads 2 can be increased or decreased to provide obstacle detection in the required direction without departing from the scope of this specification.

[0044] like Figure 2 The shading hood body 6 is provided with infrared transmitting windows 12 of the infrared transmitting tube 1 and infrared receiving windows 11 of the infrared receiving head 2 at equal intervals along a horizontal circumference. The emission angle of the infrared rays emitted by the infrared transmitting tube 1 is adjusted by adjusting the window size and depth of the infrared transmitting window 12 to control the irradiation range of the infrared transmitting tube 1. The receiving angle of the infrared rays received by the infrared receiving head 2 is adjusted by adjusting the window size and depth of the infrared receiving window 11 to control the infrared receiving range of the infrared receiving head 2.

[0045] like Figure 4 The lower part of the light shield main body 6 is provided with an infrared receiving head groove 15 with a shape similar to the appearance of the infrared receiving heads 2 evenly distributed along the horizontal circumference. The infrared receiving head groove 15 can just accommodate the infrared receiving heads 2 evenly distributed along the horizontal circumference, so that each infrared receiving head is optically isolated from each other, and at the same time it is convenient for the light shield main body 6 to be mounted on the circuit board assembly 5.

[0046] The light shield component is made of opaque dark-colored plastic material.

[0047] like Figure 7 The circuit of the multi-directional obstacle detection device includes a main control chip IC1, an operational amplifier IC2, a voltage stabilizing chip IC3, infrared transmitting tubes LED1-LED9, infrared receiving heads WH1-WH9, resistors R1-R18, ceramic capacitors C1-C17, electrolytic capacitors E1-E3, inductors L1-L3, light-emitting diodes LED10, LED11 and transistor Q1.

[0048] like Figure 7 The DAC output of the main control chip IC1 and the operational amplifier IC2 form an infrared emitting tube power adjustment module. The DAC pin 14 of the main control chip IC1 is connected to the positive input pin 3 of the operational amplifier IC2 through a series resistor R10, the reverse input pin 2 of the operational amplifier IC2 is grounded through a series resistor R11, and the reverse input pin 2 of the operational amplifier IC2 is connected to the output terminal 6 of the operational amplifier IC2 through a series resistor R12.

[0049] like Figure 7 The output terminal 6 of the operational amplifier IC2 is connected to V_LED and connected to the positive end of the infrared emitting tubes LED1-LED9. The negative ends of the infrared emitting tubes LED1-LED9 are respectively connected to the current limiting resistor R13 through the series power fine-tuning resistors R1-R9. The other end of the current limiting resistor R13 is connected to the collector of the transistor Q1. The emitter of the transistor Q1 is grounded. The base of the transistor Q1 is connected to the PWM pin 45 of the main control chip IC1 through the series resistor R14.

[0050] like Figure 7 The power supply terminals 3 of the infrared receiving heads WH1-WH9 are respectively connected to the power supply VCC2, the ground terminals 2 of the infrared receiving heads WH1-WH9 are respectively grounded, and the output terminals YK1-YK9 of the infrared receiving heads WH1-WH9 are respectively connected to the input pins 25-33 of the main control chip IC1.

[0051] like Figure 7 The input terminal 1 of the voltage regulator chip IC3 is connected to the total power input terminal VCC_IN through the series inductor L1, the ground terminal 2 of the voltage regulator chip IC3 is grounded, the output terminal 3 of the voltage regulator chip IC3 is connected to VCC, the electrolytic capacitor E1, the ceramic capacitors C11, C12, and C13 are connected in parallel between VCC and the ground, the positive end of the light emitting diode LED11 is connected to VCC, and the negative end of the light emitting diode LED11 is grounded through the series current limiting resistor R16; VCC is connected to VCC2 through the series inductor L2, the electrolytic capacitor E2, the ceramic capacitors C14, and C15 are connected in parallel between VCC2 and the ground; VCC is connected to VCC1 through the series inductor L3, the electrolytic capacitor E3, and the ceramic capacitors C16 and C17 are connected in parallel between VCC1 and the ground, and the above circuits constitute a power module.

[0052] like Figure 7 The serial port output pin 21 of the main control chip IC1 is connected to pin 2 of the output port J1 through a resistor R17, and the serial port input pin 22 of the main control chip IC1 is connected to pin 1 of the output port J1 through a resistor R18; the positive end of the light emitting diode LED10 is connected to VCC, and the negative end of the light emitting diode LED10 is connected to the input pin 2 of the main control chip IC1 through a series current limiting resistor R15.

[0053] Working principle: The basic principle of the distance measurement of the present invention is whether the infrared receiving head can receive the infrared signal emitted by the infrared transmitting tube, which is not only related to the distance between the obstacle and the infrared receiving head, but also to the intensity of the infrared signal emitted by the infrared transmitting tube. Generally, the greater the voltage applied to the two ends of the infrared transmitting tube, the greater the current flowing through the infrared transmitting tube, the greater the emission power of the infrared transmitting tube and the intensity of the infrared signal emitted by the infrared transmitting tube, so the voltage across the two ends of the infrared transmitting tube can also be used to represent the emission power of the infrared transmitting tube and the intensity of the infrared signal emitted by the infrared transmitting tube.

[0054] When the multi-directional obstacle detection device is used, under the control of the main control chip program, the main control chip IC1 controls the DAC output pin 14 to periodically output a voltage signal with a step state change by changing the control value of the DAC, and the buffer composed of the operational amplifier IC2 amplifies the current and voltage to provide the infrared emitting tubes LED1-LED9 with a V_LED power supply voltage with a step state of periodic 2.1V-3.0V change, such as Fig. 9 As shown in the waveform A, it can be found that the forward voltage V_LED of the infrared emitting tubes LED1-LED9 changes in a periodic step state, with a period of T. Under the control of the main control chip program, the PWM output pin 45 of the main control chip IC1 intermittently outputs a square wave voltage signal with a frequency of 38KHz, and controls the on and off of the infrared emitting tubes LED1-LED9 through the transistor Q1, as shown in FIG. Fig. 9 Waveform B. Under the joint control of the DAC output pin 14 of the main control chip IC1 and the PWM output pin 45 of the main control chip IC1, the infrared emitting tubes LED1-LED9 intermittently emit 38KHz infrared signals in the forward, backward, left, right, left front, left rear, right front, right rear and upward directions respectively, and the intensity of the infrared signal changes in a periodic step state, such as Fig. 9 As shown in the waveform C, the voltage across the infrared emitting tubes LED1-LED9 changes in a periodic step state.

[0055] The infrared receiving heads WH1-WH9 arranged along the front, back, left, right, left front, left back, right front, right back and upward directions receive infrared signals in various directions respectively. When the infrared receiving heads do not receive the infrared signal with a center frequency of 38KHz, the output terminal 1 of the infrared receiving head will be set to a high level. When any infrared receiving head receives the infrared signal with a center frequency of 38KHz reflected from an obstacle, the output terminal 1 of the infrared receiving head will be set to a low level.

[0056] like Figure 8—9, under the control of the main control chip program, the main control chip IC1 periodically adjusts the V_LED power supply voltage of the infrared emitting tubes LED1-LED9 by changing the control value of the DAC. The V_LED voltage is adjusted from 2.1V to 3.0V in a step state, and the DAC control value corresponds to the V_LED voltage one by one. Every time the main control chip IC1 changes the voltage of the DAC output pin 14, the main control chip program will judge and record the level state of the input port YK1-YK9 of the main control chip IC1 under the V_LED voltage. If it is a high level, it is considered that no reflected signal is received. If it is a low level, it is considered that a reflected signal is received, indicating that an obstacle has appeared in front of the infrared receiving head and the value of the direction register of the main control chip is modified. After the V_LED voltage is adjusted from 2.1V to 3.0V in a step state, the main control chip program will judge in which direction the obstacle appears and according to the level change state of the input port YK1-YK9 recorded in this cycle T and the DAC output voltage value of the main control chip IC1 when the low level appears, Fig.12 Determine the distance range of the obstacle. After the distance judgment is completed, the distance measurement of the next cycle T will begin.

[0057] See also Figure 8 ,The specific steps of obstacle detection in the main control chip program are:

[0058] A. Initialization, set the end value of the number of cycles N = 10, set the set values ​​of 10 DAC control values ​​DAC1 = 179, DAC2 = 187, DAC3 = 196...DAC 10 =255 (these DAC setting values ​​correspond to 10 V_LED values, V_LED is 2.1V, 2.2V, 2.3V...3.0V respectively), set PWM output pin 45 to output a low level signal;

[0059] B. The measurement cycle starts, the direction 1 register - direction 9 register of the internal register of the main control chip IC1 is cleared, the current cycle number i is set to 1, and the control value of the DAC is configured to be DAC1 = 179 (making V_LED 2.1V).

[0060] Set the increment count value K = 2 (i-1) =1 (binary=0000000001B);

[0061] C. After the DAC control value changes, the DAC output voltage has a jump and gradually stabilizes. When the DAC output voltage stabilizes, set the PWM output pin 45 to output a 38KHz square wave signal;

[0062] D. There is a delay and stabilization process from setting the PWM output pin 45 to output a 38KHz square wave signal until the 38KHz square wave signal is normally output at the PWM output pin. After the output 38KHz square wave signal stabilizes, read the level signals of input pins 25 - 33. If pin 25 is at a high level, the value of the direction 1 register in the internal register of the main control chip IC1 remains unchanged. If pin 25 is at a low level, the value of the direction 1 register in the internal register of the main control chip IC1 is the value of the direction 1 register plus the increment count value K; if pin 26 is at a high level, the value of the direction 2 register in the internal register of the main control chip IC1 remains unchanged. If pin 26 is at a low level, the value of the direction 2 register in the internal register of the main control chip IC1 is equal to the value of the direction 2 register plus the increment count value K;

[0063] And so on, complete the detection of pins 25 - 33 and the setting of the direction 1 register - direction 9 register corresponding to the pins;

[0064] E. Set the PWM output pin 45 to stop the 38KHz square wave signal and output a low - level signal;

[0065] F. Set the current loop count value i = i + 1, configure the control value of the DAC = DAC i , and at the same time the increment count value

[0066] K = 2 (i-1) ;

[0067] G. Repeat step C;

[0068] H. Repeat step D;

[0069] I. Repeat step E;

[0070] J. If the current loop count value i < N, repeat steps F - I;

[0071] K. If the current loop count value i = N, configure the control value of the DAC = DAC N = 255, make V_LED 3.0V, and at the same time the increment count value K = 2 (N-1) = 512 (binary = 1000000000B);

[0072] L. Repeat step C;

[0073] M. Repeat step D;

[0074] N. Repeat step E;

[0075] O. When the current loop count value i > N, the main control chip IC1 refers to Fig.12Convert the values ​​of the Direction 1 Register - Direction 9 Register into the distance values ​​of obstacles in the corresponding directions of the infrared receiving heads WH1 - WH9 corresponding to the Direction 1 Register - Direction 9 Register. For example: if the binary value of the Direction 1 Register is 1111111111B, the distance value of obstacles in the corresponding direction of the infrared receiving head WH1 is less than 0.2 meters; if the binary value of the Direction 2 Register is 1111111110B, the distance value of obstacles in the corresponding direction of the infrared receiving head WH2 is 0.2-0.4 meters; if the binary value of the Direction 3 Register is 1111111100B, the distance value of obstacles in the corresponding direction of the infrared receiving head WH3 is 0.4-0.6 meters; if the binary value of the Direction 5 Register is 1111110000B, the distance value of obstacles in the corresponding direction of the infrared receiving head WH5 is 0.8-1.0 meters; if the binary value of the Direction 7 Register is

[0076] 1110000000B, the distance value of the obstacle in the direction corresponding to the infrared receiving head WH7 is 1.4-1.6 meters; if the binary value of the direction 8 register is 1000000000B, the distance value of the obstacle in the direction corresponding to the infrared receiving head WH8 is 1.8-2.0 meters; if the binary value of the direction 9 register is 0000000000B, the distance value of the obstacle in the direction corresponding to the infrared receiving head WH9 is greater than 2.0 meters. After the distance judgment is completed, the distance values ​​of the obstacles in the directions corresponding to the infrared receiving heads WH1-WH9 are sent through the channel.

[0077] P. Return to step B and start a new measurement cycle again.

[0078] like Fig.10 For example, when the distance between the infrared receiving head WH1 in front and the obstacle is 1.7 meters, the infrared receiving head in front can only receive the infrared signal reflected by the obstacle when the V_LED voltage is between 2.9V and 3.0V within a change cycle T when the V_LED voltage is adjusted from 2.1V to 3.0V, and the minimum V_LED voltage for the infrared receiving head in front to have a low-level signal is 2.9V. The binary value of the Direction 1 register is 1100000000B. Fig.12 From the corresponding table, we can find that the DAC value corresponding to 2.9V is 247, and the corresponding distance value is 1.8 meters, so we can determine that the distance between the obstacle and the infrared receiving head in front is between 1.6 meters and 1.8 meters.

[0079] like Fig.11For example, when the distance between the right infrared receiver WH4 and the obstacle is 0.7 meters, the right infrared receiver can only receive the infrared signal reflected by the obstacle when the V_LED voltage is 2.4V, 2.5V, 2.6V, 2.7V, 2.8V, 2.9V and 3.0V, and the minimum V_LED voltage for the right infrared receiver to have a low-level signal is 2.4V, and the binary value of the Direction 4 register is 1111111000B. Fig.12 From the corresponding table, we can find that the DAC value corresponding to 2.4V is 204, and the corresponding distance value is 0.8 meters, so we can determine that the distance between the obstacle and the infrared receiving head on the right is between 0.6 meters and 0.8 meters.

[0080] The infrared transmitting tubes arranged along the front, back, left, right, left front, left back, right front, right back and upward directions respectively adjust the transmitting power (intensity) through the power fine-tuning resistors R1-R9 to ensure that the infrared signal transmitting power (intensity) of the front, back, left, right, left front, left back, right front, right back and upward directions is basically consistent when the V_LED voltage is the same. In conjunction with the infrared receiving heads arranged along the front, back, left, right, left front, left back, right front, right back and upward directions, the distance measurement of the front, back, left, right, left front, left back, right front, right back and upward directions is realized.

[0081] The distance measurement results can be communicated to external devices in real time via the serial output port J1.

[0082] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-directional obstacle detection device, comprising a circuit board assembly (5), a light shield assembly and a base (9), characterized in that: The circuit board assembly (5) comprises infrared emitting tubes (1) evenly spaced along a horizontal circumference, infrared receiving heads 2 evenly spaced along a horizontal circumference, infrared emitting tubes (3) for emitting upward and infrared receiving heads 4 for receiving upward, a main control chip, a power module, an infrared emitting tube power adjustment module, a power fine-tuning module, a carrier drive module and an output module; the light shield assembly comprises a light shield body (6), an upper infrared receiving head mounting seat (7) and an upper cover plate (8); the light shield body (6) is provided with infrared emitting windows (12) of the infrared emitting tubes and infrared receiving windows 11 of the infrared receiving heads at evenly spaced intervals along a horizontal circumference; the upper infrared receiving head mounting seat (7) is located at the upper central position of the light shield body (6) and is adhesively connected to the light shield body (6); the upper cover plate (8) is located at the middle position of the upper part of the upper infrared receiving head mounting seat (7) and is adhesively connected to the upper infrared receiving head mounting seat (7); an upper part of the upper infrared receiving head mounting seat (7) is provided with an infrared emitting window (14) facing upward; The upper cover plate (8) is provided with an infrared receiving window 13 facing upward; the shading cover assembly is mounted on the upper part of the circuit board assembly (5), the base (9) is located below the circuit board assembly, and the shading cover body (6), the circuit board assembly (5) and the base (9) are fixedly connected by screws (10); the shading cover assembly is made of opaque dark plastic material; the lower part of the shading cover body (6) is provided with an infrared receiving head groove (15), and the infrared receiving head groove (15) can just accommodate infrared receiving heads distributed at equal intervals along a horizontal circumference, so that each infrared receiving head is optically isolated from each other inside the shading cover body (6), and at the same time, it is convenient for the shading cover body (6) to be mounted on the circuit board assembly (5); the infrared receiving heads distributed at equal intervals along the horizontal circumference and the infrared receiving heads receiving upward adopt the integrated infrared receiving heads commonly used in universal infrared remote control receiving devices, also known as infrared receiving modules or infrared receiving modules (Infrared Receiver The invention relates to an integrated infrared receiving module (IRM), which is an integrated infrared receiving head formed by integrating an infrared monitoring diode, an amplifier, a limiter, a bandpass filter, an integrator circuit, a comparator and other circuits in one component and packaging them together. The integrated infrared receiving head is widely used in infrared remote control fields such as air conditioners, fans, heaters, humidifiers, televisions, DVDs, set-top boxes, remote-controlled toys, and lighting. The number of the infrared transmitting tubes (1) and the number of the infrared receiving heads 2 distributed at equal intervals along the horizontal circumference are 8 respectively, and they are arranged in the shape of front, back, left, right, left front, left back, right front, and right back, and the infrared transmitting and infrared receiving faces face outwards.

2. The multi-directional obstacle detection device according to claim 1, characterized in that: The DAC output of the main control chip IC1 of the circuit board assembly (5) and the operational amplifier IC2 form an infrared emitting tube power adjustment module; the DAC output pin of the main control chip IC1 is connected to the positive input pin of the operational amplifier IC2 through a series resistor R10, the reverse input pin of the operational amplifier IC2 is grounded through a resistor R11, and the reverse input pin of the operational amplifier IC2 is connected to the output end of the operational amplifier IC2 through a series resistor R12.

3. The multi-directional obstacle detection device according to claim 1, characterized in that: The output end of the operational amplifier IC2 of the circuit board assembly (5) is connected to the positive end of the infrared emitting tube LED1-LED9, and the negative end of the infrared emitting tube LED1-LED9 is connected to one end of the current limiting resistor R13 through a series power fine-tuning resistor R1-R9, the other end of the current limiting resistor R13 is connected to the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, the base of the transistor Q1 is connected to the PWM output pin of the main control chip IC1 through a series resistor R14, the power supply end of the infrared receiving head WH1-WH9 is respectively connected to the power supply VCC2, the ground end of the infrared receiving head WH1-WH9 is respectively grounded, and the output end YK1-YK9 of the infrared receiving head WH1-WH9 is respectively connected to the input pins 25-33 of the main control chip IC1.

4. A distance measurement method using the multi-directional obstacle detection device as claimed in claim 1, characterized in that: Under the control of the main control chip program, the main control chip IC1 controls the DAC output pin to periodically output a voltage signal with a step state change by changing the control value of the DAC, and provides a power supply voltage V_LED with a periodic step state change to the infrared emitting tubes LED1-LED9 after current and voltage amplification through the buffer formed by the operational amplifier IC2, so that the infrared emission intensity of the infrared emitting tubes LED1-LED9 changes in a periodic step state; Under the control of the main control chip program, the PWM output pin of the main control chip IC1 intermittently outputs a square wave voltage signal with a frequency of 38KHz, and controls the on and off of the infrared emitting tubes LED1-LED9 through the transistor Q1; Its working cycle is synchronized with the change cycle of the voltage signal of the step state output by the DAC output pin of the main control chip IC1; Under the joint control of the DAC output pin of the main control chip IC1 and the PWM output pin of the main control chip IC1, the infrared emitting tubes LED1-LED9 intermittently emit 38KHz infrared signals in the forward, backward, left, right, left front, left rear, right front, right rear and upward directions respectively, and the intensity of the infrared signal changes in a periodic step state.

5. The distance measurement method of the multi-directional obstacle detection device according to claim 4, characterized in that: The main control chip IC1 adopts the following steps: A. Initialization, set the end value of the number of cycles = N, set the control value of N DACs DAC1-DAC N , Set the PWM output pin to output a low level signal; B. The measurement cycle starts, the direction 1 register - direction 9 register of the internal register of the main control chip IC1 is cleared, the current cycle number i is set to 1, the control value of the DAC is configured to DAC1, and the incremental count value K is set to 2 (i-1) ; C. When the DAC output voltage is stable, set the PWM output pin to output a 38KHz square wave signal; D. After the 38KHz square wave signal output by PWM is stable, read the level signals of input pins 25 - 33 of the main control chip IC1; if pin 25 is at a high level, the value of the direction 1 register in the internal register of the main control chip IC1 remains unchanged; if pin 25 is at a low level, the value of the direction 1 register in the internal register of the main control chip IC1 is the value of the direction 1 register plus the incremental count value K; if pin 26 is at a high level, the value of the direction 2 register in the internal register of the main control chip IC1 remains unchanged; if pin 26 is at a low level, the value of the direction 2 register in the internal register of the main control chip IC1 is equal to the value of the direction 2 register plus the incremental count value K; and so on, complete the detection of pins 25 - 33 and the setting of the values of the direction 1 register - direction 9 register corresponding to the pins; E. Set the PWM output pin to stop the 38KHz square wave signal and output a low level signal; F. Set the current cycle number value i = current cycle number value i + 1, and configure the DAC control value = DAC i , while the increment count value K = 2 (i-1) ; G. Repeat step C; H. Repeat step D; I. Repeat step E; J. If the current loop count value i < N, then repeat steps F - I; K. If the current loop count value i = N, configure the DAC control value = DAC N , while the increment count value K = 2 (N-1) ; L. Repeat step C; M. Repeat step D; N. Repeat step E; O. When the current loop count value i > N, the main control chip IC1 converts the values of the direction 1 register - direction 9 register into the distance values of the obstacles in the corresponding directions of the infrared receivers WH1 - WH9 corresponding to the direction 1 register - direction 9 register. After the conversion is completed, the distance values of the obstacles in the corresponding directions of the infrared receivers WH1 - WH9 are sent through the output module; P. Return to step B to start a new measurement cycle again.

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