TWM678288U - Obstacle detection system for self-propelled device, and self-propelled device - Google Patents

Abstract

Embodiments of this disclosure provide an obstacle detection system for a self-propelled device, and a self-propelled device. The obstacle detection system is installed on an outer peripheral surface of a machine body and is configured to detect an obstacle in a traveling path of the machine body. The obstacle detection system includes at least one pair of infrared sensors, each pair including: an infrared light emitting diode for emitting infrared light; a first infrared light receiving diode for receiving reflected infrared light and converting it into a first electrical signal; and a second infrared light receiving diode for receiving reflected infrared light and converting it into a second electrical signal.

Description

Obstacle detection system for self-propelled equipment and self-propelled equipment

This disclosure is based on and claims priority to Chinese Patent Application No. 202421117840.1, filed on May 21, 2024, the entire contents of which are incorporated herein by reference. This disclosure relates to the field of self-propelled device technology, and more specifically, to an obstacle detection system for a self-propelled device and the self-propelled device itself.

With the development of artificial intelligence technology, various intelligent self-propelled devices have emerged in the market, such as robotic vacuum cleaners, robotic mops, vacuum cleaners, and lawnmowers. These intelligent self-propelled devices not only liberate labor and save on labor costs but also significantly improve cleaning efficiency. Most self-propelled devices need to automatically identify obstacles in their surroundings and perform obstacle avoidance operations during operation. For example, by integrating obstacle avoidance sensors, self-propelled devices can detect obstacles in front, to the sides, and even below in real time, thereby planning their walking path in advance and avoiding unnecessary collisions. The obstacle avoidance function not only protects furniture and the robot itself from damage but also ensures the continuity and efficiency of the robot's movement.

However, existing obstacle avoidance solutions are relatively complex and costly to implement. With the increasing popularity of self-propelled devices, especially various self-cleaning robots, the obstacle avoidance performance of these devices needs to be further enhanced and the cost needs to be further reduced.

This disclosure provides some embodiments of an obstacle detection system for self-propelled devices and self-propelled devices that can reduce the implementation cost of obstacle detection.

This disclosed embodiment provides an obstacle detection system for a self-propelled device, the self-propelled device including a machine body, the obstacle detection system being disposed on the outer peripheral surface of the machine body and configured to detect obstacles in the travel path of the machine body, the obstacle detection system including: at least one set of infrared photodiodes, each of the infrared photodiodes including: an infrared light emitting tube for emitting infrared light; a first infrared light receiving tube for receiving reflected infrared light and converting it into a first electrical signal; a second infrared light receiving tube for receiving reflected infrared light and converting it into a second electrical signal; the obstacle detection system is configured to calculate the voltage ratio of the first electrical signal to the second electrical signal, the voltage ratio being used for obstacle avoidance judgment.

In some embodiments, a buffer is provided on the forward portion of the machine body, and the at least one set of infrared pairs is disposed on the buffer.

In some embodiments, the obstacle detection system further includes a transmission lens disposed outside the at least one set of infrared pairs, the transmission lens allowing infrared light to pass through.

In some embodiments, the obstacle detection system further includes a Fresnel lens disposed in front of the optical path of the infrared emitter.

In some embodiments, the obstacle detection system includes multiple sets of infrared pairs, which are arranged horizontally and/or vertically on the front portion of the machine body.

In some embodiments, the number of infrared photodiode pairs is 1 to 30, and the spacing between adjacent infrared photodiode pairs is 2 to 5 centimeters.

In some embodiments, the obstacle detection system further includes a signal processing unit configured to receive the first electrical signal and the second electrical signal, calculate the voltage ratio between the first electrical signal and the second electrical signal, compare the calculated voltage ratio with a preset threshold, and determine the situation of obstacles ahead based on the comparison result.

In some embodiments, the infrared pair is soldered onto a flexible printed circuit board (PCB).

In some embodiments, the obstacle detection system further includes a connector for electrical connection to the self-propelled device's mainboard.

In some embodiments, each of the infrared pairs is correspondingly soldered onto a flexible printed circuit board, and the plurality of flexible printed circuit boards are connected by flexible printed circuit (FPC) cables; at least one of the signal processing unit and the connector is disposed on one of the plurality of flexible printed circuit boards.

This disclosed embodiment provides an obstacle detection system for a self-propelled device, the self-propelled device including a machine body, the obstacle detection system being disposed on the outer peripheral surface of the machine body and configured to detect obstacles in the travel path of the machine body, the obstacle detection system including multiple sets of infrared pairs, the infrared pairs being arranged at preset array intervals; wherein, each set of infrared pairs includes an infrared light emitting tube, and the infrared light emitting tubes of two adjacent sets are configured to be illuminated asynchronously.

This disclosure provides a self-propelled device including the obstacle detection system described above.

Compared with existing technologies, the obstacle detection system for self-propelled devices and the self-propelled devices provided in this disclosure embodiment utilize a special infrared photocell structure and signal processing method to achieve obstacle detection and avoidance, which can significantly reduce the cost and hardware complexity of obstacle avoidance modules for self-propelled devices.

To make the purpose, technical solutions, and advantages of this disclosure clearer, a more detailed description of this disclosure will be provided below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, not all of them. Based on the embodiments in this disclosure, all other embodiments obtained by a person skilled in the art without making any progressive work are within the scope of protection of this disclosure.

The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The singular forms “a,” “said,” and “the” used in this disclosure and the scope of the appended claims are also intended to include the plurality, and “plural” generally includes at least two unless the context clearly indicates otherwise.

It should be understood that the term "and/or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and/or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character "/" in this article generally indicates that the preceding and following related objects have an "or" relationship.

It should also be noted that the terms "comprising," "including," or any other variation thereof are intended to cover non-exclusive inclusion, such that a product or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or device. Unless otherwise specified, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the product or device that includes said element.

In related technologies, obstacle avoidance solutions for self-propelled devices are generally complex and costly to implement. For example, existing structured light-based obstacle avoidance sensors project specific patterns of light into the environment and determine the shape and position of objects by analyzing the reflected light patterns. Structured light technology requires complex image processing and calculations, resulting in high implementation costs. Similarly, existing time-of-flight (TOF)-based obstacle avoidance sensors calculate the distance to objects by measuring the time it takes for light to travel from emission to reflection back to the receiver. However, TOF-based obstacle avoidance sensors require high-precision timing, which also leads to high implementation costs.

Therefore, this disclosure embodiment provides an obstacle detection system for a self-propelled device, the self-propelled device including a machine body, the obstacle detection system being disposed on the outer peripheral surface of the machine body and configured to detect obstacles in the travel path of the machine body, the obstacle detection system including: at least one set of infrared photodiodes, each of the infrared photodiodes including: an infrared light emitting tube for emitting infrared light; a first infrared light receiving tube for receiving reflected infrared light and converting it into a first electrical signal; a second infrared light receiving tube for receiving reflected infrared light and converting it into a second electrical signal; the obstacle detection system is configured to calculate the voltage ratio of the first electrical signal to the second electrical signal, the voltage ratio being used for obstacle avoidance judgment.

The alternative embodiments disclosed herein are described in detail below with reference to the accompanying figures.

This disclosure embodiment provides a possible application scenario, which includes self-propelled devices such as sweeping robots, mopping robots, vacuum cleaners, lawnmowers, etc. As an example, a sweeping robot will be used for illustration. Referring to Figure 1, the self-propelled device is a sweeping robot 10, which may include a machine body 110, a sensing system 120, a controller, a drive module, a cleaning system, an energy system, and a human-machine interaction module, etc.

The machine body 110 includes a forward portion 111 and a rearward portion 112, and has an approximately circular shape (i.e., both the front and rear are circular). It is understood that the machine body 110 may also have other shapes. A buffer 122 may be further provided on the forward portion 111 of the machine body 110. The buffer 122 may be made of an elastic material, possessing good energy absorption performance, and can effectively reduce the impact force when the machine collides with an obstacle, protecting equipment and furniture. The buffer 122 may also be equipped with various sensors.

The sensing system 120 is used to provide the control system with various position information and motion status information of the machine. The sensing system 120 may include sensing devices such as collision sensors, cliff sensors, magnetometers, accelerometers, gyroscopes, and odometers disposed on or inside the equipment body 110.

The control system is located on the circuit board within the main body 110 of the device and includes a computing processor, such as a central processing unit and an application processor, that communicates with non-transitory memory, such as hard disks, flash memory, and random access memory. The control system can control the drive module to make the robot vacuum cleaner 10 respond based on obstacle information fed back by the sensing system 120.

The cleaning system can be a dry cleaning system or a wet cleaning system. As a dry cleaning system, the primary cleaning function comes from the sweeping system comprised of a roller brush, dustbin, fan, air outlet, and the connecting components between these four parts. The roller brush, which interferes with the floor, sweeps up debris and carries it to the suction port between the roller brush and the dustbin. There, it is drawn into the dustbin by the suction generated by the fan and passing through the dustbin. Dry cleaning systems may also include side brushes with rotating shafts at an angle relative to the floor to move debris into the roller brush area of the cleaning system.

The energy system includes rechargeable batteries, such as nickel-hydrogen batteries and lithium batteries. The rechargeable batteries can be connected to a charging control circuit, a battery pack charging temperature detection circuit, and a battery undervoltage monitoring circuit. These circuits are then connected to a microcontroller control circuit.

The human-computer interaction system includes buttons on the panel of the main body 110 for users to select functions; it may also include a display screen and/or indicator lights and/or a speaker to show the user the current status of the machine or function options; and it may also include a mobile client application.

Referring to Figures 2 and 3, Figure 2 is a front view of a robotic vacuum cleaner 10 equipped with the obstacle detection system provided in this embodiment, and Figure 3 is a schematic diagram of the position distribution of the infrared photocells in Figure 2. An obstacle detection system is further provided on the robot body 110. The obstacle detection system is used to detect obstacles in the travel path of the robot body.

The obstacle detection system includes at least one set of infrared photodiodes 210. Each set of infrared photodiodes 210 may include: a first infrared light receiver 211, a second infrared light receiver 212, and an infrared light emitter 213. The infrared light emitter 213 is used to emit infrared light, the first infrared light receiver 211 is used to receive the reflected infrared light and convert it into a first electrical signal, and the second infrared light receiver 212 is used to receive the reflected infrared light and convert it into a second electrical signal.

In some embodiments, the obstacle detection system is located on the forward section 111 of the main body 110, specifically on the buffer 122 of the forward section 111. During the cleaning process, the drive module propels the robot vacuum cleaner 10 across the ground. The buffer 122 detects obstacles in the path of the robot vacuum cleaner 10 via the obstacle detection system located thereon. The robot vacuum cleaner 10 can control the drive module to respond to the obstacle event detected by the obstacle detection system on the buffer 122, such as slowing down, stopping, or turning.

In some embodiments, the obstacle detection system further includes a signal processing unit (not shown) for receiving a first electrical signal and a second electrical signal, and calculating the voltage ratio of the first and second electrical signals. This voltage ratio can be used for subsequent obstacle avoidance judgment. The signal processing unit can be a microcontroller (MCU). The signal processing unit can calculate the ratio of the voltage value of the first electrical signal to the voltage value of the second electrical signal using a built-in ratio calculation module. Let the voltage value of the first electrical signal be V1 and the voltage value of the second electrical signal be V2, then the voltage ratio R is defined as: R = V2/V1.

In some embodiments, the calculated voltage ratio R can be compared with multiple preset thresholds to determine the situation of obstacles ahead, such as their location and size. For example, multiple voltage ratio thresholds T1, T2, T3, etc., can be set based on experimental data and actual usage environments for different levels of obstacle avoidance judgment and operation. Obstacle avoidance operations include no obstacle avoidance, triggering deceleration, and immediately executing stop or turn operations. By calculating the voltage ratio output by the two infrared receivers, accurate obstacle judgment and avoidance can be achieved.

In some embodiments, the obstacle detection system includes multiple sets of infrared photodiodes 210. These sets of infrared photodiodes 210 are disposed on the forward portion 111 of the machine body 110 to ensure effective detection of obstacles ahead as the machine body 110 moves forward. In some embodiments, the transmitting and receiving tubes of each infrared photodiode 210 are disposed on a buffer 122, specifically on the front surface of the buffer 122, to ensure unobstructed light transmission and reception.

In some embodiments, the number of infrared photodiode pairs 210 can be 1 to 30, for example 9 to 17, and the spacing between adjacent infrared photodiode pairs 210 can be 1 to 10 cm, for example 2 to 5 cm, to ensure that there are no blind spots in detection and that there is little interference between adjacent infrared photodiode pairs 210.

In some embodiments, multiple sets of infrared photodiodes 210 are arranged horizontally on the forward portion 111 of the machine body 110, forming a straight or slightly curved array to ensure coverage of all possible paths ahead. In some embodiments, the sets of infrared photodiodes 210 can also be arranged vertically to cover obstacles at different heights. For example, on higher equipment, the sets of infrared photodiodes 210 can be distributed vertically to detect obstacles at different heights. Furthermore, to improve detection capabilities in complex environments, a combined arrangement can be used, combining horizontal and vertical arrangements to form a two-dimensional detection network, enhancing obstacle avoidance.

In some embodiments, within a single infrared pair 210, an infrared emitting tube 213 is located at the center of the pair, and a first infrared receiving tube 211 and a second infrared receiving tube 212 are respectively arranged on both sides of the infrared emitting tube 213; in other embodiments, the first infrared receiving tube 211 is located at the center of the pair, and the infrared emitting tube 213 and the second infrared receiving tube 212 are respectively arranged on both sides of the first infrared receiving tube 211; or the second infrared receiving tube 212 is located at the center of the pair, and the infrared emitting tube 213 and the first infrared receiving tube 211 are respectively arranged on both sides of the second infrared receiving tube 212.

In some embodiments, the buffer 122 typically has a certain curvature, and the infrared photodiodes 210 are disposed close to the buffer 122, with the infrared photodiodes 210 and the buffer 122 maintaining the same curvature and/or the arrangement of multiple sets of infrared photodiodes 210 maintaining the same curvature as the buffer 122.

In some embodiments, the obstacle detection system further includes a transmission lens 220 disposed outside the infrared pair 210. The transmission lens 220 is made of a special infrared-transmitting material to ensure efficient transmission of infrared light. In some embodiments, the transmission lens 220 can also block visible light while ensuring efficient transmission of infrared light to reduce ambient light interference. As an example, the transmission lens 220 is black, possessing high infrared transmittance and low visible light transmittance to reduce ambient light interference and optimize detection performance. In some embodiments, the transmission lens 220 maintains the same curvature as the buffer 122.

In some embodiments, the obstacle detection system further includes a Fresnel convex lens (not shown), which is positioned in front of the optical path of the infrared emitting tube 213. If there are multiple sets of infrared pairs 210, a Fresnel convex lens can be installed in front of the infrared emitting tube 213 within each set of infrared pairs 210. Through the focusing and guidance of the Fresnel convex lens, the infrared beam can be effectively focused, giving the infrared light a strong directionality, reducing beam divergence, and reducing mutual interference between adjacent infrared emitting tubes 213. Furthermore, the Fresnel lens is smaller in size than a conventional lens, making it particularly suitable for applications requiring multiple lenses as disclosed in this invention.

In some embodiments, the Fresnel lens is convex inwardly, with its inner surface designed to be concave, thereby ensuring the overall consistency of the optical system. In some embodiments, the Fresnel lens is mounted directly in front of the infrared emitter 213 and aligned with the axis of the infrared emitter 213 to ensure optimal optical performance.

In some embodiments, the infrared pair 210 is soldered to a flexible printed circuit board (not shown), which can be further secured to the transmission lens 220 by means of adhesive, clips or screws. Specifically, adhesive backing fixation involves pre-applying adhesive, such as double-sided tape, to the back of the flexible printed circuit board. The adhesive installation process is simple and quick; simply attach the printed circuit board to the inner surface of the transmissive lens 220 and apply appropriate pressure to ensure a firm fixation. Clip fixation can be achieved by providing several clip slots on the inner side of the transmissive lens 220, which match the clip holes on the flexible printed circuit board. Screw fixation can be achieved by providing corresponding screw holes on the edges of the flexible printed circuit board and the transmissive lens 220, aligning the screw holes on the flexible printed circuit board with the holes on the transmissive lens 220, inserting the screws, and tightening them.

Flexible printed circuit boards (PCBs) are made of highly flexible materials and possess excellent bending resistance and electrical properties. In some embodiments, the thickness of the PCB can be 0.1 to 0.2 mm to ensure stable operation even when bent.

In some embodiments, the obstacle detection system further includes a connector (not shown) for electrical connection to the robot vacuum's main board. The connector allows data and signal exchange between the circuitry on the printed circuit board and the robot vacuum's main board control system. For example, the obstacle detection system sends an obstacle avoidance signal to the robot vacuum's main board via the connector, and the robot vacuum's main board control system further performs corresponding operations based on the obstacle avoidance signal, such as stopping, turning, or decelerating.

In some embodiments, each infrared diode pair 210 is soldered onto an independent small flexible printed circuit board (PCB). The PCBs are connected via flexible printed circuit board (PCB) cables, which are thin, flexible, and easy to install. Soldering each infrared diode pair 210 separately facilitates installation and replacement. A signal processing unit can be located on one of the independent PCBs and exchange data and signals with the infrared diodes 210 on other PCBs via PCB cables to process the signals received by each infrared diode 210. A connector can be mounted on one of the independent PCBs. The connector can be mounted on the same flexible printed circuit board as the signal processing unit.

In other embodiments, all infrared transducers 210 are soldered onto a single flexible printed circuit board to form an integrated circuit board module, which reduces the number of cables. The flexible printed circuit board design improves the adaptability of the infrared transducers 210 on complex curved surfaces and provides flexible installation options. Referring to Figure 4, this disclosed embodiment further provides an obstacle avoidance method for the obstacle detection system as described in the aforementioned embodiment. The obstacle avoidance method includes the following steps: Step S110, controlling the infrared light emitting tube to emit infrared light; Step S120, controlling the first infrared light receiving tube to receive the reflected infrared light and obtain a first electrical signal, and controlling the second infrared light receiving tube to receive the reflected infrared light and obtain a second electrical signal; Step S130, calculating the voltage ratio between the first and second electrical signals, and judging the situation of obstacles ahead based on the voltage ratio to form an obstacle avoidance strategy.

In some embodiments, the self-propelled device may include one or more sets of infrared photodiodes 210. One or more sets of infrared photodiodes 210 are disposed on the forward portion 111 of the machine body 110 to ensure effective detection of obstacles ahead as the machine body 110 moves forward.

When the self-propelled device includes multiple sets of infrared pairs 210, the infrared light emitting tubes 213 of the infrared pairs 210 can be configured to be lit asynchronously to avoid two adjacent infrared light emitting tubes 213 emitting infrared light at the same time, thereby further reducing interference.

The voltage ratio R between the first and second electrical signals is defined as: R = V2/V1, where V1 is the voltage value of the first electrical signal and V2 is the voltage value of the second electrical signal. In some embodiments, the calculated voltage ratio R can be compared with multiple preset thresholds to determine the situation of obstacles ahead, such as their location and size. For example, multiple voltage ratio thresholds T1, T2, T3, etc., can be set based on experimental data and actual usage environments for different levels of obstacle avoidance judgment and obstacle avoidance strategies, such as no obstacle avoidance required, triggering deceleration, immediately executing stop or turn operations, etc. This embodiment can accurately identify obstacles by calculating the voltage ratio of the outputs of the two infrared receivers, thereby forming a corresponding obstacle avoidance strategy.

Compared with existing technologies, the obstacle detection system and self-propelled device provided in this disclosure embodiment utilize a special infrared pair 210 structure and signal processing method to realize obstacle detection and avoidance, which can significantly reduce the cost and hardware complexity of the obstacle avoidance module of the self-propelled device.

Finally, it should be noted that the embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the others. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be found in the method section.

The above embodiments are only used to illustrate the technical solutions disclosed herein, and are not intended to limit them. Although the disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments disclosed herein.

The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the patent application of the present invention shall be covered by the present invention.

10: Robotic vacuum cleaner 110: Main body/equipment body 111: Forward section 112: Rearward section 120: Sensing system 122: Buffer 210: Infrared pair 211: First infrared receiver 212: Second infrared receiver 213: Infrared emitter 220: Transmitting lens S110, S120, S130: Steps

The accompanying drawings, incorporated in and forming part of this specification, illustrate embodiments consistent with this disclosure and, together with the specification, serve to explain the principles of this disclosure. It will be apparent that the drawings described below are merely some embodiments of this disclosure, and other drawings can be derived from these drawings by those skilled in the art without further effort.

Figure 1 is a schematic diagram of the three-dimensional structure of a sweeping robot involved in some embodiments disclosed herein.

Figure 2 is a front view of a robot vacuum cleaner equipped with an obstacle detection system provided in some embodiments of this disclosure.

Figure 3 is a schematic diagram of the position distribution of the infrared pair in Figure 2.

Figure 4 is a flowchart of an obstacle avoidance method for an obstacle detection system for a self-propelled device provided in some embodiments of this disclosure.

120: Sensing System

210: Infrared pair

211: First Infrared Receiver Tube

212: Second Infrared Receiver Tube

213: Infrared light emitting tube

220: Transmission lens

Claims (20)

An obstacle detection system for a self-propelled device, wherein the self-propelled device includes a machine body, and the obstacle detection system is disposed on the outer peripheral surface of the machine body and configured to detect obstacles in the travel path of the machine body. The obstacle detection system includes: at least one set of infrared photocells, each of the infrared photocells including: an infrared light emitting tube for emitting infrared light; a first infrared light receiving tube for receiving reflected infrared light and converting it into a first electrical signal; and a second infrared light receiving tube for receiving reflected infrared light and converting it into a second electrical signal. The obstacle detection system is configured to calculate the voltage ratio between the first electrical signal and the second electrical signal, and the voltage ratio is used for obstacle avoidance judgment. The infrared emitting tube is located at the center of the infrared pair, and the first infrared receiving tube and the second infrared receiving tube are respectively arranged on both sides of the infrared emitting tube; or the first infrared receiving tube is located at the center of the infrared pair, and the infrared emitting tube and the second infrared receiving tube are respectively arranged on both sides of the first infrared receiving tube; or the second infrared receiving tube is located at the center of the infrared pair, and the infrared emitting tube and the first infrared receiving tube are respectively arranged on both sides of the second infrared receiving tube. The obstacle detection system as described in claim 1, wherein a buffer is provided on the forward portion of the machine body, and the at least one set of infrared photocells is disposed on the buffer. The obstacle detection system as described in claim 1 further includes a transmission lens disposed outside the at least one set of infrared pairs, the transmission lens allowing infrared light to pass through. The obstacle detection system as described in claim 1 further includes a Fresnel convex lens disposed in front of the optical path of the infrared emitting tube. The obstacle detection system as described in claim 1 includes multiple sets of the infrared pairs, which are arranged horizontally and/or vertically on the front portion of the machine body. The obstacle detection system as described in claim 5, wherein the number of infrared photocell pairs is 1 to 30, and the spacing between adjacent infrared photocell pairs is 2 to 5 centimeters. The obstacle detection system as described in claim 1 further includes a signal processing unit configured to receive the first electrical signal and the second electrical signal, calculate the voltage ratio between the first electrical signal and the second electrical signal, compare the calculated voltage ratio with a preset threshold, and determine the situation of obstacles ahead based on the comparison result. The obstacle detection system as described in claim 1, wherein the infrared pair is soldered onto a flexible printed circuit board. The obstacle detection system as described in claim 1 further includes a connector for electrically connecting to the mainboard of the self-propelled device. The obstacle detection system as described in claim 9, wherein each of the infrared pairs is correspondingly soldered onto a flexible printed circuit board, and the plurality of flexible printed circuit boards are connected to each other via flexible printed circuit board cables; at least one of the signal processing unit and the connector is disposed on one of the plurality of flexible printed circuit boards. An obstacle detection system for a self-propelled device, the self-propelled device including a machine body, wherein the obstacle detection system is disposed on the outer peripheral surface of the machine body and configured to detect obstacles in the travel path of the machine body, the obstacle detection system including multiple sets of infrared photodiodes, the infrared photodiodes being arranged at preset array intervals; wherein each set of infrared photodiodes includes an infrared light emitting tube, and the infrared light emitting tubes of two adjacent sets are configured to be illuminated asynchronously. The obstacle detection system as described in claim 11, wherein each set of infrared pairs further includes two infrared light receiving tubes for receiving reflected infrared light and converting it into an electrical signal. The obstacle detection system as described in claim 12, wherein the infrared emitting tube is located at the center of the infrared pair tube, and the two infrared receiving tubes are respectively arranged on both sides of the infrared emitting tube. The obstacle detection system as described in claim 12, wherein two of the infrared light receivers are arranged adjacent to each other, and the infrared light emitters are arranged on one side of the infrared light receivers. The obstacle detection system as described in claim 12, wherein multiple sets of the infrared pairs are arranged horizontally on the buffer of the machine body. The obstacle detection system as described in claim 15, wherein, in the horizontal direction, the infrared emitting tubes and the infrared receiving tubes in two adjacent sets of infrared pairs are arranged differently. The obstacle detection system as described in claim 12, wherein multiple sets of the infrared pairs are arranged vertically on the buffer of the machine body. The obstacle detection system as described in claim 17, wherein, in the vertical direction, the infrared emitting tubes and the infrared receiving tubes in two adjacent sets of infrared pairs are arranged in the same manner. The obstacle detection system as described in claim 11, wherein the number of infrared pairs is 1 to 30, and the distance between two adjacent infrared pairs is 2 to 5 centimeters. A self-propelled device comprising an obstacle detection system as described in any of claims 1 to 10 or claims 11 to 19.