Robot and cliff detection device and method

Abstract

The invention discloses a robot and a cliff detection device and method, and relates to the technical field of robot safety detection, the cliff detection device comprises a signal acquisition unit, a switch unit and at least one cliff sensor; the at least one cliff sensor is arranged on the robot, and each cliff sensor is connected with the signal acquisition unit; the signal acquisition unit is connected with the switch unit, the switch unit is arranged on a power supply line of the motor, and the motor is used for driving the robot to move; the cliff sensor is used for detecting the current distance between the robot and the front ground in real time and sending the current distance to the signal acquisition unit; and the signal acquisition unit is used for driving the switch unit to disconnect the power supply circuit so as to stop supplying power to the motor when the current distance sent by any cliff sensor is determined to be greater than a preset distance threshold value. The situation that the robot falls can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of robot safety detection, and in particular to a robot, a cliff detection device and a method. Background Art

[0002] As people's living standards improve, more and more robotic devices are entering people's daily lives, such as sweeping robots.

[0003] In order to prevent the robot from falling during movement, the ground needs to be detected to find steps, stairs, etc. for protection. The inventors have found that the existing robot cliff detection method has a large delay, which often causes the robot to fall. Summary of the invention

[0004] The technical problem to be solved by the embodiments of the present invention is that the existing cliff detection method of the robot has a large delay, which often causes the robot to fall.

[0005] In order to solve the above problems, in a first aspect, an embodiment of the present invention provides a cliff detection device for a robot, comprising: a signal acquisition unit, a switch unit, and at least one cliff sensor;

[0006] The at least one cliff sensor is disposed on the robot, and each cliff sensor is connected to the signal acquisition unit;

[0007] The signal acquisition unit is connected to the switch unit, the switch unit is arranged on the power supply line of the motor, and the motor is used to drive the robot to move;

[0008] The cliff sensor is used to detect the current distance between the robot and the ground in front in real time, and send the current distance to the signal acquisition unit;

[0009] The signal acquisition unit is used to drive the switch unit to disconnect the power supply line to stop supplying power to the motor when it is determined that the current distance sent by any cliff sensor is greater than a preset distance threshold.

[0010] A further technical solution is that the switch unit includes an NMOS tube and a PMOS tube;

[0011] The gate of the NMOS tube is connected to the signal acquisition unit, the source of the NMOS tube is grounded, and the drain of the NMOS tube is connected to the gate of the PMOS tube;

[0012] The source of the PMOS tube is connected to a power supply, and the drain of the PMOS tube is connected to the motor; the power supply is used to supply power to the motor.

[0013] A further technical solution is that the switch unit further includes a first resistor, a second resistor and a third resistor;

[0014] The gate of the NMOS tube is connected to the signal acquisition unit through the first resistor;

[0015] The first end of the second resistor is connected to the drain of the NMOS tube, the second end of the second resistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the power supply.

[0016] A further technical solution is that the detection frequency of the cliff sensor satisfies the following formula: Where, f is the detection frequency of the cliff sensor, V max is the maximum moving speed of the robot, and m is in meters.

[0017] A further technical solution is that the cliff sensor includes a triangulation ranging sensor.

[0018] A further technical solution is that a mounting plate is provided at the bottom of the robot, and the at least one cliff sensor is arranged on the outer edge of the mounting plate.

[0019] In a second aspect, an embodiment of the present invention provides a robot, comprising the cliff detection device of the robot as described in the first aspect.

[0020] In a third aspect, an embodiment of the present invention provides a cliff detection method, which is applied to a signal acquisition unit in a cliff detection device of a robot as described in the first aspect, and the method includes:

[0021] Receive the current distance between the robot and the ground ahead from any cliff sensor;

[0022] Determining whether the current distance is greater than a preset distance threshold;

[0023] When it is determined that the current distance is greater than a preset distance threshold, the switch unit is driven to disconnect the power supply line to stop supplying power to the motor.

[0024] Compared with the prior art, the technical effects achieved by the embodiments of the present invention include:

[0025] In the embodiment of the present invention, a hardware linkage method is used to cut off the power supply of the motor. That is, when the current distance between the robot and the ground in front detected by the cliff sensor is greater than a preset distance threshold, the signal acquisition unit directly cuts off the power supply of the motor. Compared with the conventional method of sending a signal to the motor driver and then letting the driver determine whether to turn off the motor, this solution saves the processing time of the driver, stops the movement of the robot in time, greatly reduces the movement distance of the robot from the detection of the cliff to the stop of the robot, and thus greatly reduces the possibility of the robot falling. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0028] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0029] Figure 1 A structural block diagram of a cliff detection device for a robot provided by an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the distribution of cliff sensors of a cliff detection device of a robot provided by an embodiment of the present invention at the bottom of the robot;

[0031] Figure 3 Another structural block diagram of a cliff detection device for a robot provided by an embodiment of the present invention;

[0032] Figure 4 Another structural block diagram of a cliff detection device for a robot provided by an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of a flow chart of a cliff detection method provided by an embodiment of the present invention.

[0034] Reference numerals

[0035] Signal acquisition unit 10 , motor 40 , mounting plate 50 , cliff sensor 21 , motor driving chip 31 , switch unit 32 . DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Similar component numbers in the drawings represent similar components. Obviously, the embodiments described below 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.

[0037] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0038] It should also be understood that the terms used in this description of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the description of the embodiments of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0039] See also Figure 1 The embodiment of the present invention provides a cliff detection device for a robot, wherein the robot includes a motor 40, and the motor 40 is used to drive the robot to move. The number of the motors 40 can be two. The two motors 40 are respectively used to drive two wheel hubs of the robot.

[0040] like Figure 1 As shown, in the embodiment of the present invention, the cliff detection device of the robot includes a signal acquisition unit 10, a switch unit 32 and at least one cliff sensor 21.

[0041] At least one cliff sensor 21 is disposed on the robot, and each cliff sensor 21 is connected to the signal acquisition unit 10. The signal acquisition unit 10 may be specifically an MCU chip. For example, in this embodiment, the number of cliff sensors 21 is 4.

[0042] The signal acquisition unit 10 is connected to the switch unit 32 , and the switch unit 32 is arranged on the power supply line of the motor 40 .

[0043] In the embodiment of the present invention, the cliff sensor 21 is used to detect the current distance between the robot and the ground in front in real time, and send the current distance to the signal acquisition unit 10.

[0044] The signal acquisition unit 10 is used to drive the switch unit 32 to disconnect the power supply line to stop supplying power to the motor 40 when it is determined that the current distance sent by any cliff sensor 21 is greater than a preset distance threshold.

[0045] The detection signal of the cliff sensor 21 includes a plurality of distance detection values ​​arranged in time sequence (the distance detection value is the current distance between the robot and the ground in front). If the distance detection value of the cliff sensor 21 is greater than a preset distance threshold, such as 10 cm, it is determined that a cliff is detected. The distance threshold can be set by those skilled in the art, and is not specifically limited in the embodiment of the present invention. For example, the distance threshold can be set to 10 cm.

[0046] In the embodiment of the present invention, the power supply of the motor 40 is cut off by hardware linkage. That is, when the current distance between the robot and the ground in front detected by the cliff sensor 21 is greater than a preset distance threshold, the signal acquisition unit 10 directly cuts off the power supply of the motor 40. Compared with the conventional method of sending a signal to the driver of the motor 40, and then the driver determines whether to turn off the motor 40, this solution saves the processing time of the driver, stops the movement of the robot in time, and greatly reduces the movement distance of the robot from the detection of the cliff to the stop of the robot, thereby greatly reducing the situation of the robot falling.

[0047] At the same time, by arranging multiple cliff sensors 21 on the robot, multi-directional detection can be achieved. For example, the forward directions of 0°, 45°, 90°, 135° and 180° can all be covered for detection, thereby effectively avoiding missed detection.

[0048] Further, the cliff sensor 21 includes a power supply interface, a grounding interface, and an output interface, wherein the power supply interface is used to be connected to a first power source, the grounding interface is grounded, and the output interface is connected to the signal acquisition unit 10. The first power source is used to power the cliff sensor 21. The output interface is used to output a detection signal to the signal acquisition unit 10, wherein the detection signal includes the current distance between the robot and the ground in front.

[0049] Furthermore, participate Figure 2 A mounting plate 50 is provided at the bottom of the robot, and at least one cliff sensor 21 is provided on the outer edge of the mounting plate.

[0050] When there are multiple cliff sensors 21, the multiple cliff sensors 21 are all arranged on the outer edge of the mounting plate 50. For example, multiple cliff sensors 21 are evenly arranged on the outer edge of the front side of the mounting plate 50, so that the cliff can be detected at the first time. Specifically, the number of cliff sensors 21 can be four. Furthermore, in some embodiments, multiple cliff sensors 21 are distributed around the bottom of the robot, thereby realizing all-round cliff detection around the robot (i.e., judging whether the detection value of the cliff sensor 21 is greater than the preset distance threshold; if so, judging that the cliff is detected), thereby improving safety. At the same time, in order to improve the detection efficiency, only the cliff sensors 21 located in the direction of the robot are subjected to cliff detection, thereby improving the detection efficiency. For example, when the robot is moving forward, only the cliff sensors 21 in the forward direction are used for cliff detection; when the robot is moving backward, only the cliff sensors 21 in the backward direction are used for cliff detection.

[0051] Further, see Figure 3 In one embodiment, the robot includes a power supply VCC_MAI N, and the switch unit 32 is connected to the power supply VCC_MAI N, the signal acquisition unit 10 and the motor 40 respectively; when receiving the shutdown signal sent by the signal acquisition unit 10, the switch unit 32 cuts off the power supply VCC_MAI N to the motor 40. The switch unit 32 cuts off the power supply VCC_MAI N to the motor 40, so that the motor 40 can stop working immediately. In this embodiment, the switch unit 32 directly turns off the power circuit of the motor 40 to ensure that the motor 40 loses power and loses the driving force, so that the robot can stop moving quickly, effectively avoiding the robot from falling. Compared with the conventional method of sending a signal through the driver of the motor 40 and then judging whether to turn off the motor 40, the above-mentioned hardware linkage method can save the driver's software judgment time and avoid software bugs and other problems, and has higher efficiency and reliability. The power supply VCC_MAI N is used to power the motor.

[0052] In one embodiment, the switch unit 32 includes an NMOS tube Q2 and a PMOS tube Q1. The gate of the NMOS tube Q2 is connected to the signal acquisition unit 10, the gate of the NMOS tube Q2 is connected to the signal acquisition unit 10, the source of the NMOS tube Q2 is grounded, the drain of the NMOS tube Q2 is connected to the gate of the PMOS tube Q1, the source of the PMOS tube Q1 is connected to the power supply VCC_MAI N, and the drain of the PMOS tube Q1 is connected to the motor 40. The power supply VCC_MAI N is used to power the motor.

[0053] Furthermore, the switch unit further includes a first resistor R1, a second resistor R2 and a third resistor R3. The gate of the NMOS transistor Q2 is connected to the signal acquisition unit 10 through the first resistor R1. The first resistor R1 plays a current limiting role, thereby protecting the gate of the NMOS transistor Q2.

[0054] Further, a first end of the second resistor R2 is connected to the drain of the NMOS tube, a second end of the second resistor R2 is connected to a first end of the third resistor R3, and a second end of the third resistor R3 is connected to the power supply VCC_MAI N. The second resistor R2 and the third resistor R3 play a current limiting role, thereby protecting the gate of the PMOS tube Q1.

[0055] Furthermore, participate Figure 4 In one embodiment, the cliff detection device further includes a motor driver chip 31, the signal acquisition unit 10 is connected to the motor driver chip 31, and the motor driver chip 31 is connected to the motor 40. In this embodiment, the signal acquisition unit sends a shutdown signal to the motor driver chip 31 when the detection value of the cliff sensor 21 is greater than a preset distance threshold; when the motor driver chip 31 receives the shutdown signal from the signal acquisition unit 10, it controls the motor 40 to stop working, thereby preventing the robot from falling. In this embodiment, the motor driver chip 31 immediately activates the braking function upon receiving the shutdown signal, and immediately brakes and locks the shaft of the robot's motor 40 to achieve the function of braking and stopping. For some occasions where immediate stopping is required, the braking function can achieve immediate real-time stopping, thereby ensuring that the robot does not fall into the steps or cliffs.

[0056] Furthermore, the detection frequency of the cliff sensor 21 satisfies the following formula: Where, f is the detection frequency of the cliff sensor 21, V max is the maximum moving speed of the robot, and m is in meters.

[0057] For a walking robot, at least two detection cycles are required from the discovery of a sudden change in the ground distance to the completion of the detection and judgment. In the embodiment of the present invention, the detection frequency of the cliff sensor 21 satisfies the following formula: Where, f is the detection frequency of the cliff sensor 21, V max is the maximum moving speed of the robot, and m is in meters, so as to ensure that the moving distance of the robot is less than 0.1m within two detection cycles to prevent the robot from falling.

[0058] For example, in one embodiment, the detection frequency of the cliff sensor 21 is 50 Hz, that is, the time for two cycle detections is 40 ms. For the robot, it moves at a speed of 1 M / S. Within the 40 ms time required for the detection to be completed, the actual moving distance is 0.04 meters, ensuring that the robot will not fall.

[0059] Furthermore, the cliff sensor 21 is a triangulation distance sensor. The model of the triangulation distance sensor is GP2Y0A51SK0F or ORA2S01. The detection cycle of the triangulation distance sensor is 16ms, which can achieve fast detection and effectively prevent the robot from falling.

[0060] The principle of the triangulation distance sensor is as follows: after the light source (laser or infrared light) of the triangulation distance sensor is emitted to the surface of the object, diffuse reflection occurs and is reflected to the triangulation distance sensor for receiving the light signal. Then the CCD (Chargecoup led Device) image is used to process the time difference between emission and reception, and the distance to the object is calculated through trigonometric function. The triangulation distance sensor can achieve long-distance measurement without the need for a reflector or low reflectivity. It also has the advantages of wide measurement range, short response time, compact overall structure, and easy installation.

[0061] An embodiment of the present invention provides a robot, and the robot includes the cliff detection device proposed in any one of the above embodiments.

[0062] See also Figure 5 An embodiment of the present invention provides a cliff detection method, which is applied to the signal acquisition unit in the cliff detection device of the above embodiment, and includes the following steps S1-S3.

[0063] S1, receives the current distance between the robot and the ground in front from any cliff sensor.

[0064] In a specific implementation, the detection signal of the cliff sensor is sent to the signal acquisition unit in real time. The detection signal includes multiple distance detection values, that is, the current distance between the robot and the ground in front.

[0065] S2, determining whether the current distance is greater than a preset distance threshold.

[0066] In a specific implementation, the detection signal of the cliff sensor includes a plurality of distance detection values ​​arranged in time order, the distance detection value being the current distance between the robot and the ground in front, and if the distance detection value of the cliff sensor is greater than a preset distance threshold, such as 10 cm, it is determined that a cliff is detected. The distance threshold can be set by those skilled in the art, and is not specifically limited in the embodiments of the present invention, for example, the distance threshold can be set to 10 cm.

[0067] S3, when it is determined that the current distance is greater than the preset distance threshold, the switch unit is driven to disconnect the power supply line to stop supplying power to the motor.

[0068] In a specific implementation, if the detection value of the cliff sensor is greater than a preset distance threshold, a shutdown signal is sent to the switch unit so that the switch unit cuts off the power supply to the motor, thereby effectively preventing the robot from falling.

[0069] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0070] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0071] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0072] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0074] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0075] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0076] The above is a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A robot cliff detection device, characterized in that: include: a signal acquisition unit, a switch unit, and at least one cliff sensor; The at least one cliff sensor is disposed on the robot, and each cliff sensor is connected to the signal acquisition unit; The signal acquisition unit is connected to the switch unit, the switch unit is arranged on the power supply line of the motor, and the motor is used to drive the robot to move; The cliff sensor is used to detect the current distance between the robot and the ground in front in real time, and send the current distance to the signal acquisition unit; The signal acquisition unit is used to drive the switch unit to disconnect the power supply line to stop supplying power to the motor when it is determined that the current distance sent by any cliff sensor is greater than a preset distance threshold.

2. The cliff detection device according to claim 1, characterized in that: The switch unit includes an NMOS tube and a PMOS tube; The gate of the NMOS tube is connected to the signal acquisition unit, the source of the NMOS tube is grounded, and the drain of the NMOS tube is connected to the gate of the PMOS tube; The source of the PMOS tube is connected to a power supply, and the drain of the PMOS tube is connected to the motor; the power supply is used to supply power to the motor.

3. The cliff detection device according to claim 2, characterized in that: The switch unit further includes a first resistor, a second resistor and a third resistor; The gate of the NMOS tube is connected to the signal acquisition unit through the first resistor; The first end of the second resistor is connected to the drain of the NMOS tube, the second end of the second resistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the power supply.

4. The cliff detection device according to claim 1, characterized in that: The detection frequency of the cliff sensor satisfies the following formula: Where, f is the detection frequency of the cliff sensor, V max is the maximum moving speed of the robot, and m is in meters.

5. The cliff detection device according to claim 1, characterized in that: The cliff sensor comprises a triangulation sensor.

6. The cliff detection device according to claim 1, characterized in that: A mounting plate is provided at the bottom of the robot, and the at least one cliff sensor is arranged on the outer edge of the mounting plate.

7. A robot, characterized in that: A cliff detection device comprising a robot as described in any one of claims 1-6.

8. A cliff detection method, characterized in that: A signal acquisition unit used in a cliff detection device of a robot according to any one of claims 1 to 6, the method comprising: Receive the current distance between the robot and the ground ahead from any cliff sensor; Determining whether the current distance is greater than a preset distance threshold; When it is determined that the current distance is greater than a preset distance threshold, the switch unit is driven to disconnect the power supply line to stop supplying power to the motor.

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