WO2011032307A1

WO2011032307A1 - Contact sensor for lawns

Info

Publication number: WO2011032307A1
Application number: PCT/CN2009/073930
Authority: WO
Inventors: 林小冬
Original assignee: Lin Xiaodong
Priority date: 2009-09-15
Filing date: 2009-09-15
Publication date: 2011-03-24
Also published as: CN102498364B; CN102498364A

Abstract

A contact sensor for lawns comprises an upper casing and a lower casing connected by a middle connecting tube (6), an amplifying circuit (2) is arranged in the upper casing, one end of a general wiring harness (1) is connected with the amplifying circuit (2), the other end of the general wiring harness (1) extends out of the upper casing, an upper plug (5) is arranged at the lower end of the upper casing, a lower plug (7) is arranged at the upper end of the lower casing, a sensor unit is arranged in the lower casing or arranged in the upper casing and the lower casing separately. The contact sensor for lawns mounted on the chassis of a mowing robot is used for identifying the lawns and the length of the lawns, and can adapt to the working environment and conditions without affecting the normal walking of the mowing robot on the lawns.

Description

Specification for a grass contact sensor

Technical field

[1] The present invention relates to a mowing robot accessory device, and more particularly to a grass contact sensor. In particular, a sensing device mounted on the chassis of a mowing robot to sense the length of grass and grass.

Background technique

[2] Most existing mowing robots cannot actively identify the grass on the ground and the length of the grass before and after being cut. As a result, the mowing robot itself cannot directly identify the work area where the mowing activity is to be performed. The range of activities, peers can not choose to save energy and efficient walking path and working mode by recognizing the change of the length of the grass before and after cutting.

[3] In order to solve these problems, most known mowing robots are solved by adding additional auxiliary facilities and equipment. The most common method is to install signal generators and signal lines on the working ground. The signal line is pre-determined to determine the working area where the mowing work will be performed. The signal generator loads a specific signal to the signal line, and the mowing robot senses the signal and the signal line through a specific sensor mounted on the body. The existence and specific location to achieve the purpose of identifying the work area. In view of how to achieve energy-efficient walking paths and working modes, some existing mowing robots are realized by monitoring the change of the speed or current of the mowing motor, and some are realized by precise positioning of GPS satellites, and some It is realized by using the north-south direction of geomagnetism to accurately navigate.

[4] These solutions increase the complexity of the mowing robot control system and greatly increase the production cost, and they also cause great inconvenience to the end consumers and operators when they are used. Can not actively adapt to the changed environment, requires the participation and resetting of operators to work.

[5] The reason for this is the lack of a sensing device that directly recognizes the length of the grass and the length of the grass. Because when the mowing robot is mowing the grass on the grass, its working environment and working conditions are very complicated and bad, and ordinary sensors cannot be used for a long time. When the mowing robot works on the grass, its movement route and movement direction will change frequently, and the contact state of the sensing device and the grass installed on the body, such as the contact position and the contact direction, will also change frequently; The same amount of grasshoppers The grass and grass juice and the dust raised on the ground will continue to pollute until the sensor is damaged; the numerous debris on the grass and the high and low undulating ground will also crash or even damage the sensing device; Moisture and outdoor weather and even rainy days can affect the normal use and service life of the sensing device. In addition, the sensing device is very prone to aging and wear due to the long-term contact and collision between the grass and the grass. The combination of these factors makes it difficult for general sensing devices and sensors to be used in such a harsh working environment for a long time. At the same time, in order to avoid affecting the normal walking and work of the mowing robot on the grass, the sensing device used to identify the length of the grass and the grass cannot produce excessive walking resistance to the mowing robot, and the angular and oversized The structure can not meet such requirements. All of this plagues the development and application of mowing robots.

Summary of the invention

[6] In view of the deficiencies in the prior art, an object of the present invention is to provide a grass contact sensor which is mounted on a mowing robot chassis for recognizing grass and grass length, capable of overcoming and competent working environment of the mowing robot and Conditions, peers will not affect the normal walking of the mowing robot on the grass.

[7] In order to achieve the above object, the technical solution drawn by the present invention is:

[8] A grass contact sensor, comprising: an upper casing and a lower casing connected by an intermediate connecting pipe 6,

[9] The upper casing is provided with an amplifying circuit 2, one end of the bus bundle 1 is connected to the amplifying circuit 2, and the other end is extended from the upper casing.

[10] The upper end of the upper casing is provided with an upper plug 5,

[11] The lower end of the lower casing is provided with a lower plug 7

[12] The sensor unit is disposed in the lower housing or in the upper housing and the lower housing.

[13] In addition to the above technical solution, the sensor unit is an acoustic-electric converter 9, and the acoustic-electric converter 9 is disposed in the lower plug 7 and electrically connected to the amplifying circuit 2.

[14] Based on the above technical solution, the sensor unit is an angle sensor 111, and the angle sensor 111 is disposed in the lower plug 7 and electrically connected to the amplifying circuit 2.

[15] On the basis of the above technical solution, the sensor unit is a pair of infrared transmitting tubes and receiving tubes, and the infrared transmitting tubes and receiving tubes are respectively disposed in the upper plug column 5 and the lower plug column 7, and the amplifying circuit 2 Electrical connections.

[16] On the basis of the above technical solution, the upper casing includes an upper mounting sealing cover 3 and an upper connection that are fastened up and down The sleeve 4, the upper plug 5 is disposed in the upper connecting sleeve 4; the upper connecting sleeve 4 is connected to the intermediate connecting tube 6.

[17] On the basis of the above technical solution, the lower casing includes a lower connecting sleeve 8 and a lower contact sealing cover 10 that are fastened up and down, and the lower plug 7 is disposed in the lower connecting sleeve 8; the lower connecting sleeve 8 It is connected to the intermediate connecting pipe 6.

[18] Based on the above technical solution, the intermediate connecting pipe 6 is an elastic hose.

[19] The grass contact sensor of the present invention is installed on the chassis of the mowing robot to identify the length of the grass and the grass, and can overcome the working environment and conditions of the mowing robot, and the same does not affect the mowing robot in the grass. Normal walking on the upper.

DRAWINGS

[20] The present invention has the following figures:

[21] Figure 1 Schematic diagram of the grass contact sensor

[22] Figure 2 Schematic diagram of the cross-sectional structure of the grass contact sensor

[23] Figure 3 circuit schematic of the amplifier circuit

[24] Figure 4 is a partially enlarged schematic view of the invention mounted on the chassis of the mowing robot

[25] FIG. 5 shows an embodiment of the present invention mounted on a mowing robot

[26] Figure 6 Figure 5 is a side view

[27] FIG. 7 is a schematic view showing the tilting state of the mowing robot to which the present invention is installed

[28] Fig. 8 Schematic diagram of the mowing robot to which the present invention is mounted horizontally lifted off the ground

[29] FIG. 9 is a schematic view of a mowing robot equipped with the present invention walking on a cut grass

[30] FIG. 10 is a schematic view of a mowing robot equipped with the present invention walking on a grass to be cut

[31] FIG. 11 A modified embodiment of the present invention

detailed description

[32] The present invention will be further described in detail below with reference to the accompanying drawings.

[33] The technical solution of the present invention is to use an acoustic electrical converter to receive an acoustic signal generated by contacting a grass raft, the acoustic electrical converter being mounted in a closed elastic housing having a contact end from the ground. A certain height. When the contact end of the sensor housing contacts the grass 吋, the acoustic-electric converter receives the sound wave generated by the object contact 吋 and converts it into weak electric energy, and then amplifies the amplified signal to output a level signal complying with the digital signal requirement, This senses the length of the grass and grass that it is exposed to.

[34] As shown in FIG. 1 and 2, the grass contact sensor of the present invention includes an upper body connected by an intermediate connecting pipe 6. The intermediate connecting tube 6 is an elastic hose; the elastic connecting tube 6 may be a latex tube or the like, and the intermediate connecting tube 6 may also be made of a well-known elastic material, and can be bent at will in contact with the grass 吋 shell. Deformation

[35] The upper casing is provided with an amplifying circuit 2, one end of the bus bundle 1 is connected to the amplifying circuit 2, and the other end is extended outside the upper casing'

[36] The upper end of the upper casing is provided with an upper plug 5,

[37] Lower plug 7 at the top of the lower housing

[38] The acoustic-electric converter 9 is provided in the lower plug 7 and is electrically connected to the amplifying circuit 2. The acoustic-electrical converter refers to an electronic component that can convert sound waves into electrical energy, and representative devices such as electret capacitors (commonly known as microphones), micro-vibration motors, and the like.

[39] On the basis of the above technical solution, the upper casing includes an upper mounting sealing cover 3 and an upper connecting sleeve 4 that are fastened up and down, and the upper plug 5 is disposed in the upper connecting sleeve 4; 4 is connected to the intermediate connecting pipe 6.

[40] Based on the above technical solution, the lower casing includes a lower connecting sleeve 8 and a lower contact sealing cover 10 that are fastened up and down, and the lower plug 7 is disposed in the lower connecting sleeve 8; the lower connecting sleeve 8 It is connected to the intermediate connecting pipe 6. The lower contact sealing cover in the technical solution should be made of a material with good acoustic wave transmission characteristics, for example: made of solid material such as dense plastic or metal.

[41] In the above technical solution, the sealing cover is mounted thereon, the upper connecting sleeve, the intermediate connecting tube, the lower connecting sleeve, and the lower contact sealing cover together form a closed cavity which is relatively isolated from the outside. The first structure of the closure makes the invention highly resistant to water and dust. Secondly, it can isolate most of the sound signals that are already present in the non-contact 外界, so that the invention has high anti-interference performance.

[42] In the above technical solution, the intermediate connecting pipe 6 is made of an elastic material such as a latex tube which can be freely bent and deformed and can be automatically recovered. When the sensor housing and the grass are in contact, the intermediate connecting tube 6 will be deformed by bending, and when it is disengaged, it can be restored. Such a structure can reduce the damage to the sensor itself by contacting the grass raft, thereby prolonging the fatigue resistance and service life of the sensor, and also reducing the contact resistance to the mowing robot. Such a structure is also very easy to adjust the overall size of the sensor housing. When it is necessary to adjust the different heights of the sensor from the ground, it is only necessary to change the length of the intermediate flexible connecting tube.

[43] The intermediate connecting tube 6 can also be made of non-deformable hard material, and even the above sensor can be used. The upper connecting sleeve 4, the upper plug 5, the intermediate connecting tube 6 and the lower plug 7 in the housing structure, and the lower connecting sleeve 8 are combined into one component. One of the biggest differences between this modified structure and the previously described structure is that the present invention is not free to bend and deform in contact with the grass, thereby producing a large running resistance, but can also substantially satisfy and realize the basics of the present invention. Function, should be considered to fall within the scope of protection of the present invention

[44] As shown in FIG. 3, it is a circuit schematic diagram of the amplifying circuit of the present invention, which is a basic signal amplifying circuit, and the MIC shown in the figure is an acoustic-electric converter 9, and its representative device such as an electret capacitor Or a miniature vibration motor, etc.

[45] The grass contact sensor of the invention has compact structure, convenient installation, sensitive induction, same fatigue resistance, impact resistance, strong waterproof and dustproof performance, can adapt to harsh outdoor use environment, and is especially suitable for outdoor mowing. The chassis of the robot is used to sense the height of the grass and grass on the ground. The mowing robot equipped with the above sensor can sense the length of the grass and the length of the grass on the ground, so that the mowing robot can identify the active area to be mowing without any additional auxiliary equipment, and can The changing state of the length of the grass before and after cutting is automatically selected to walk the corresponding walking path and working mode.

[46] The grass contact sensor of the present invention has the following characteristics:

[47] 1. The invention utilizes the acoustic signal generated by the sensor to close the casing in contact with the grass raft as an inductive medium to sense the contact state, and the sensing and the sensation are sensitive;

[48] 2. The outer casing of the invention is a closed casing which is relatively isolated from the outside, so that it can isolate most external interference signals and has strong waterproof and dustproof performance;

[49] 3. The intermediate connecting pipe of the invention is made of elastic material, and can be bent and deformed freely in contact with the grass, thereby reducing damage to the sensor itself in frequent contact with the grass, and improving the product. Fatigue resistance and service life, while also reducing the forward resistance of the mowing robot.

[50] 4. The overall structure of the present invention is smooth and compact, easy to install, and does not cause a large contact resistance.

4 is a partially enlarged schematic view showing the mounting of the mowing robot on the chassis of the mowing robot. As shown in FIG. 4, the chassis of the mowing robot 41 is provided with the grass contact sensor 42 of the present invention, and the grass contact sensor 42 is provided. The end is in contact with the grass 44 on the ground, and the corresponding signal is collected by the acoustic-electric converter 9, and the intermediate connecting pipe 6 is correspondingly bent and deformed by the force generated by the contact, so that the end is bent and deformed accordingly. The bending deformation can play a buffering role to protect the sensor itself; the second can also reduce the walking resistance of the mowing robot, without affecting the normal walking and work on the grass.

[52] FIG. 5 is an embodiment of the present invention mounted on a mowing robot, wherein a total of five grass contact sensors A, B, C, D, E are mounted on the chassis of the mowing robot, and their separation The ground heights are different, wherein the ground contact heights hl=1.5 cm of the grass contact sensors A and E, and the ground height h2 of the grass contact sensors 8, C and D are equal to or slightly larger than the ground height h of the mowing blades. According to common sense, the length of grass on normal grass is more than 1.5 cm. If the length of the grass on the ground is less than 1.5 cm, it can be considered that the grass does not need mowing robot to cut grass on it. For mowing robots, grasses with a length of 1.5 cm or less = "no grass", and grasses with a length greater than 1.5 cm = "grass". Of course, if necessary, the height of hi can be reduced to meet the actual needs. It is also common knowledge that grasses that are less than the height of the mowing blades from the ground h are "cut" grasses, and grasses that are longer than the height of the mowing blades from the ground h are uncut or "to be cut". As shown in Fig. 5, the grass contact sensors A and E can be used to determine whether there is a "grass" or "no grass" state, and the grass contact sensors C, D can be used to determine whether the "cut" or "to be cut" grass.

Figure 6 is a side elevational view of the embodiment of Figure 5, in which the grass contact sensors B, C, D, E are omitted and only the grass contact sensor A is shown. As shown in Fig. 6, when the mowing robot is walking on a grass having a length of more than 1.5 cm, the lower contact sealing cover 10 of the grass contact sensor A is in close contact with the grass on the grass, and the grass contact sensor A outputs a high-level signal " Γ to map this contact state; when the mowing robot walks on "no grass" that is less than 1.5 cm in length, the grass contact sensor A and the grass lose contact, the grass contact sensor A outputs The low level signal "0" maps this state. Such a level signal change is particularly noticeable and critical at the boundary of the work area indicated by the dotted line in the "grass" and "grass free" areas. The mowing robot can identify the working boundary and the working area according to the state of change of the signal output by the grass sensor A.

7 is a schematic view showing a tilting state of the mowing robot to which the present invention is mounted, and when the mowing robot to which the present invention is mounted is accidentally tilted or artificially turned over, the grass contact sensor A is in a long position. The non-contact state (while the grass contact sensor E will be in contact between long turns), the long turns here are usually in the order of seconds. The grass contact sensor A continuously outputs a low level signal "0" to map this state, and the mowing robot can judge the occurrence of a dangerous situation, thereby controlling the machine to enter the stop. State alarm protection program for machine alarms.

[55] FIG. 8 is a schematic view of the mowing robot to which the present invention is mounted horizontally lifted off the ground, and the stalk contact sensors A and E are both in a non-contact state, and they continuously output a low level signal "0". To map this state, the mowing robot judges that there is a situation other than this, thereby controlling the machine to enter the safety state of the shutdown alarm.

9 is a schematic view of a mowing robot equipped with the present invention walking on a cut grass, the grass contact sensors B, C, D are in a non-contact state, and they output a low level signal "0" to map this. Non-contact type too.

[57] FIG. 10 is a schematic view of a mowing robot equipped with the present invention walking on a grass to be cut, the squid contact sensors B, C, D are in contact with the grass, and they output a high level signal "Γ to map this Kind of contact state.

[58] As shown in FIG. 9 and FIG. 10, when the installation height of the grass contact sensor of the present invention is equal to or slightly larger than the ground height h吋 of the mowing blade, the mowing robot to which the present invention is mounted may be the grass sensor according to the present invention. The level signal is output to identify whether the grass is cut grass or grass to be cut, so that the corresponding walking path is selected for efficient and energy-saving mowing work. For example, when the mowing robot equipped with the grass contact sensor of the present invention travels on the grass as shown in FIG. 9, the sensors B, C, D output a low level signal "0", and the mowing robot judges the grass on which it is located. The grass has been cut, thus controlling the mowing motor to stop working to save energy, while continuing to drive the machine to find the grass to be cut. For example, when the mowing robot equipped with the grass contact sensor of the present invention travels on the grass as shown in FIG. 10, the sensors B, C, D output a high level signal "1", and the mowing robot judges the current position. The grass on the grass is the grass to be cut, so that a control command is issued to restart the mowing motor for mowing. The same mowing robot can also control the robot to perform regular walking paths such as circular involutes for walking and working, which not only saves energy but also improves the efficiency and effectiveness of mowing work.

[59] The present invention may also have various modified embodiments without departing from the basic structural features of the present invention. As shown in FIG. 11, an angle sensor is used while maintaining the overall outer casing structure of the present invention. 111 replacing the acoustic-electrical converter 9, using the bending deformation of the outer casing in contact with the grass raft to trigger the angle sensor installed in the casing, thereby realizing the induction of the grass contact, such a modified embodiment should also be considered It is within the scope of the invention. Also maintaining the overall outer casing structure of the present invention In this case, it is also possible to replace the acoustic-electric converter 9 with a pair of infrared transmitting tubes and receiving tubes, for example: an infrared transmitting tube is mounted on the upper plug 5, and an infrared receiving tube is mounted on the lower plug 7. When the changed sensor housing is bent and deformed in the middle of the contact pipe 6 contacting the grass, the infrared receiving tube can not receive the light emitted by the infrared emitting tube; when the sensor is out of contact with the grass, the sensor housing is restored to the original state, infrared The receiving tube receives the light from the infrared transmitting tube again. Such a modified embodiment is also considered to fall within the scope of the present invention.

Claims

claims

[1] 1. A grass contact sensor, characterized by: including an upper housing and a lower housing connected by an intermediate connecting pipe (6),

There is an amplifying circuit (2) in the upper casing. One end of the bus harness (1) is connected to the amplifying circuit (2), and the other end extends out of the upper casing. The lower end of the upper casing is provided with an upper plunger (5).

The upper end of the lower housing is provided with a lower plunger (7), and the sensor unit is located in the lower housing or separately located in the upper housing and the lower housing.

[2] 2. The grass contact sensor according to claim 1, characterized in that: the sensor unit is an acoustic-electric converter (9), and the acoustic-electric converter (9) is located in the lower plunger (7), and Electrically connected to the amplifier circuit (2).

[3] 3. The grass contact sensor according to claim 1, characterized in that: the sensor unit is an angle sensor (111), and the angle sensor (111) is located in the lower plunger (7) and is connected to the amplification circuit (111). 2) Electrical connection.

[4] 4. The grass contact sensor according to claim 1, characterized in that: the sensor unit is a pair of infrared transmitting tubes and receiving tubes, and the infrared transmitting tubes and receiving tubes are respectively arranged on the upper plunger (5), into the lower plunger (7) and electrically connected to the amplifier circuit (2).

[5] 5. The grass contact sensor according to claim 1 or 2 or 3 or 4, characterized in that: the upper housing includes an upper mounting sealing cover (3) and an upper connecting sleeve (4) that snap up and down. ), the upper plunger (5) is located in the upper connecting sleeve (4); the upper connecting sleeve (4) is connected to the intermediate connecting pipe (6).

[6] 6. The grass contact sensor according to claim 1 or 2 or 3 or 4, characterized in that: the lower housing includes a lower connecting sleeve (8) that snaps up and down and a lower contact sealing cover (10) ), the lower plunger (7) is located in the lower connecting sleeve (8); the lower connecting sleeve (8) is connected to the middle connecting pipe (6).

[7] 7. The grass contact sensor according to claim 1 or 2 or 3 or 4, characterized in that: the intermediate connecting pipe (6) is an elastic hose.

[8] 8. The grass contact sensor according to claim 5, characterized in that: the intermediate connecting pipe (6) is an elastic hose.

[9] 9. The grass contact sensor according to claim 6, characterized in that: the intermediate connecting pipe (6) is an elastic hose.