Mobile robot

Abstract

The present invention relates to a mobile robot comprising a robot body and at least one robot leg. In order to provide a mobile robot with a structure that is as simple as possible and yet robust, it is proposed in the context of the present invention that the robot leg comprises an axially movable rod, which is pivotally guided in the robot body, and that means for axially moving the rod and means for pivoting the rod are provided. Thus, a device fixed to the robot body usually cooperates with the other robot leg to move the rod three-dimensionally relative to the robot body, changing the horizontal and vertical position of the robot body, as well as its inclination with respect to the ground.

Description

[Technical field]

[0001] The present invention relates to a mobile robot comprising a robot body and at least one robot leg. [Background technology]

[0002] In addition to robots that include wheels and tracks, some robots include legs that are adapted to move the robot body, change its height, and tilt the robot body.

[0003] WO 2020 / 169285 A1 discloses a robotic leg having at least two joints, each joint interconnecting two nodes, each joint comprising a cam, the robotic leg further comprising at least one actuator and a common tendon interconnecting each of the cams.

[0004] These types of robotic legs modeled after nature have relatively complex structures including joints that make them complicated to manufacture, likely to require repairs, and limit the height to which the robot body can be lifted to the length of the segments when the joints are extended. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 169285A1 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention addresses the problem of providing a mobile robot that significantly expands the range that the robot body can climb and has a structure that is as simple as possible, yet robust. [Means for solving the problem]

[0007] In the present invention, this problem is solved by a mobile robot as described in the preamble, in which the robot leg comprises an axially movable rod and pivotally guided in the robot body, means for axially moving the rod and means for pivoting the rod are provided, an opening is located at a point provided in the robot body relative to the robot leg, and the rod is movable in the opening perpendicularly and at a variable angle relative to the opening.

[0008] The robot leg of the present invention includes a rod on which the robot body is supported, the lower end of the rod being positioned on the ground. The rod is axially movably connected to the outer edge of the robot body, or an opening is located at a location on the robot body relative to the leg, the rod being movable vertically at the opening and at a variable angle relative to the opening. These devices move the rod in the longitudinal direction of the rod relative to the robot body, and change the angle of the rod axis relative to the robot body in two dimensions.

[0009] Thus, a device fixed to the robot body typically coordinates with other robot legs to move the rod in three dimensions relative to the robot body, changing the horizontal and vertikal (vertical) position of the robot body, as well as its inclination relative to the ground. The length of the rod can be multiple times the size of the robot body.

[0010] Such robotic legs are cost-effective to manufacture and maintain due to their simple construction.

[0011] One aspect of the present invention is that the opening in the robot body is continuous.

[0012] Advantageously, the robot body is in this case movable along the entire length of the rod. The robot legs may be arranged within the robot body. The rod may extend through a continuous opening in the robot body.

[0013] A preferred configuration of the present invention is that the rod is a first threaded rod including an external thread and an axially extending groove, the external thread engages with an internal thread, the internal thread is connected to the robot body so as to be rotatable and pivotable but not axially movable, a pin is provided which engages with the groove to prevent radial rotation of the rod, a drive which rotates the internal thread of the rod is provided as a means for axially moving the rod, and at least one further drive which is directly or indirectly connected to the first threaded rod is provided as a means for pivoting the rod.

[0014] Axial movement of the threaded rod allows the robot leg to move up and down (z-axis), while an additional drive unit pivots the threaded rod to move the robot leg left and right (x-axis) or forward and backward (y-axis).

[0015] An advantageous development of the invention consists in that two drives directly or indirectly connected to the first threaded rod so as to be offset from one another are provided as means for pivoting the rod.

[0016] The two drives may be offset from each other diagonally or perpendicularly. This configuration allows for both side-to-side movement (x-axis) and front-to-back movement (y-axis). The two drives may be configured as servo motors.

[0017] Instead of two drives, it is also possible to provide a single drive which pivots the rod in two axes using deflection means for pivoting the rod.

[0018] In this case, it is sufficient for the rod to be partially (in some parts) configured as a threaded rod.

[0019] The length of these segments determines the vertical adjustability of the robot leg.

[0020] Alternatively, the rod may preferably be a rectangular rack, and a drive including complementary engagement elements which engage with the rack may be provided as a means for axially moving the rod, and at least one further drive connected directly or indirectly to the rack may be provided as a means for pivoting the rod.

[0021] An advantageous development of the invention consists in that a control device is provided.

[0022] To allow the robot to utilize the leg structure in various ways, the drive must be equipped with signal transmitters for indicating rotation or another display, from which the control device can derive the position of the legs. Having determined the starting position at an initial stage, the control device can move each robot's feet to any position within the reachable volume, spread the legs at different angles depending on the required upright stability, move the legs around and over high obstacles, and position the robot body at any height between the ground and the length of the threaded rod.

[0023] An advantageous configuration is that a tilt sensor is provided.

[0024] The tilt sensor is advantageous for control, so that the robot body can be tilted as desired, and in particular, the robot body can always be kept horizontal at a freely variable height, regardless of the nature of the terrain.

[0025] Particularly advantageously, the tilt sensor can be used to determine whether the robot leg is in contact with the ground, for example, when the robot leg is moved towards the ground, contact with the ground can be determined based on the change in tilt angle as the robot leg is moved.

[0026] The path the robot travels can be very steep and does not require the removal of obstacles. For example, the robot can step into and climb over a hedge. The robot can operate in shallow water and, if padded on its feet, on muddy ground. The robot leaves almost no footprints on the ground along its path.

[0027] This robot is particularly suitable for use in agriculture and horticulture, such as in vineyards, tea gardens, rice fields, etc. For this, in addition to the control software for movement, the robot needs a device for the specific application task, usually one or two robot arms, including the associated control device, also needs a camera and a pattern recognition program, for example to identify a particular plant or pest, and finally a program for orientation and navigation in the terrain. If several robots are operating simultaneously, their movements need to be related to each other and their tasks need to be coordinated. [Brief description of the drawings]

[0028] The configuration of the present invention will be described in more detail below with reference to the drawings.

[0029] [Figure 1] FIG. 2 is a side view showing details of a mobile robot associated with a robotic leg according to the present invention. [Diagram 2] FIG. 2 is a plan view of the underside of the mobile robot of FIG. [Diagram 3] FIG. 2 is a side view of a further mobile robot according to the present invention; [Figure 4] FIG. 13 is a side view of a further mobile robot. [Diagram 5] FIG. 5 is a cross-sectional view of the mobile robot of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] 1 and 2 show an exemplary embodiment of a mobile robot including a robotic leg.

[0031] In FIG. 1, an arrow points from top to bottom to specify the viewing direction of FIG.

[0032] In the exemplary embodiment, a long threaded rod 2 with an external thread and an axially extending groove is used for the up and down movement. The threaded rod 2 passes through an opening in the robot body 1, which has rounded edges and is slightly larger than the cross section of the threaded rod 2. A rectangular frame 5 is suspended from the threaded rod 2, through which the threaded rod 2 moves axially. Inside the frame 5, a first ball bearing 6a, configured for pressure application, is pressed (slides on the threaded rod 2) onto the threaded rod 2 with its upper side facing the opening. The first ball bearing 6a abuts against a first nut 7a, which is provided with worm wheel teeth on the outside. A long sleeve 10 rigidly connects this first nut 7a to a further nut 11, which in turn abuts against a second ball bearing 6b, configured for axial pressure application. A rotatable ring of this second ball bearing 6b abuts against the frame 5. The two nuts 7 a , 11 and the sleeve 10 connecting them are free to rotate within the frame 5 .

[0033] A motor 9 including a worm shaft 8a is laterally fixed to the frame 5 as a first drive part. The worm shaft engages with the worm wheel of the first nut 7a to rotate the worm wheel, thereby rotating the two nuts 7a, 11, and moving the threaded rod 2 within the frame 5. A first pin 12 fixed to the frame 5 engages with a groove in the threaded rod 2 so as not to rotate axially together.

[0034] The robot body 1 abuts against a frame 5 via a short spacer sleeve 4. Tension springs 3 in the upper corners of the frame 5 keep the threaded rod 2 centred in the opening in the robot body 1 while allowing angular movement of the threaded rod 2.

[0035] In left and right movement, only the lower side of the frame 5 opposite the opening of the robot body 1 is moved. The link mechanism 13 connects the lower edge of the frame 5 by a joint to the end face of a second short threaded rod 14 provided with a groove.

[0036] A second nut 7b with a worm gear thread on the outside rotates on this short threaded rod 14. A motor 16, which rotates the second nut 7b by means of a worm shaft 8b, is fixed to the robot body as a further drive. U-shaped holders 15, also fixed to the robot body 1 and on both sides of the second nut 7b, prevent the second nut 7b from moving axially, and second pins 12, which engage in grooves on the short threaded rod 14, prevent the second nut 7b from rotating axially. A ball bearing between the holders and the second nut 7b reduces friction on the holders 15. The rotating second nut 7b moves the short threaded rod 14 in the U-shaped holders 15, changing the left-right angle of the long threaded rod 2 of the robot leg by means of the link mechanism and the frame 5.

[0037] Further linkages constructed in a similar manner, including short threaded rods and nuts rotated by worm drives in U-shaped holders, are fixed to the lower edge of the frame 5 at right angles to the linkages for side-to-side movement. These push the robot legs forward and backward.

[0038] Alternatively, any type of linear drive may be used for side to side and fore to aft movement.

[0039] Instead of a worm drive for the up and down movement, the nut may alternatively include a gear wheel instead of a worm wheel on the outside, which gear wheel is driven by a pinion of a motor shaft extending parallel to the threaded rod.

[0040] Depending on the speed of the motor, a reduction gear may be required.

[0041] To improve the speed of movement, a rectangular rack may be used instead of a threaded rod, which eliminates the need for a groove to prevent axial rotation, improves the speed of movement, and also requires a motor with a reduction gear or a stepper motor instead of a nut, worm drive, and a simple motor for fine adjustment.

[0042] FIG. 3 shows a further exemplary embodiment of a mobile robot including robotic legs.

[0043] In the exemplary embodiment, a long threaded rod 2, including an external thread and an axially extending groove 17, is used for up and down movement. The threaded rod 2 passes through an opening 22 in the robot body 1, which has rounded edges and is slightly larger than the cross section of the threaded rod 2. The opening 22 in the robot body 1 may be continuous. In this case, the threaded rod 2 may extend through the continuous opening 22 in the robot body 1. A U-shaped frame 5 is positioned below the opening 22, through which the threaded rod 2 moves axially.

[0044] Inside the frame 5, a spacer sleeve 4 is pressed onto the threaded rod with its upper side facing the opening 22. The spacer sleeve 4 is rigidly connected to the frame 5 and forms a sliding bearing for the axial movement of the threaded rod 2. The threaded rod 2 extends through an opening in a first ball joint 18a. The robot leg is fixed to the robot body 1 via the first ball joint 18a. The first ball joint 18a allows the threaded rod 2 to move angularly together with the frame 5.

[0045] A first ball bearing 6a, configured to apply pressure, rests against the first ball joint 18a. The first ball bearing 6a is pressed against the threaded rod 2. The first ball bearing 6a rests against a first nut 7a, configured on the outside as a spur gear. This first nut 7a rests against a second ball bearing 6b, configured to apply axial pressure. A rotatable ring of the two ball bearings 6a, 6b rests against the nut 7a. The nut 7a can rotate freely in the frame 5. A long sleeve 10 rests against the ball bearing 6b. The long sleeve 10 extends through the frame 5 and is connected to the frame 5. The two sleeves 4, 10 connected to the frame prevent the first nut 7a from moving axially along the threaded rod 2 relative to the frame 5.

[0046] A motor 9 including a first pinion 19a is laterally fixed to the frame 5 as a first drive. The first pinion 19a engages with a gear wheel of a first nut 7a to rotate the gear wheel, thereby rotating the nut 7a and moving the threaded rod 2 within the frame 5. A pin 12 fixed to the frame 5 engages in a groove in the threaded rod 2 so as not to rotate axially therewith.

[0047] Tension springs 3 at the upper corners of the frame 5 prevent the frame 5 from rotating radially about the threaded rod 2, allowing angular movement of the frame 5, and therefore the threaded rod 2, about the ball joint 18.

[0048] In the left-right movement, only the lower side of the frame 5 opposite the opening 22 of the robot body 1 is moved. The plain bearing 20 is connected to the frame 5 by a long sleeve 10. Two cardan joints 21 are fixed to the outside of the plain bearing 20 at an angle of 90°. One end of the cardan joints 21 is connected to the plain bearing 20 and the other end is connected to the short threaded rod 14. The cardan joints 21 allow various angular positions of the short threaded rod 14 relative to the threaded rod 2. In this case, the cardan joints 21 prevent axial rotation of the short threaded rod 14.

[0049] The second nut 7b, configured on the outside as a spur gear, rotates on the short threaded rod 14. A motor 16, which rotates the second nut 7b by means of a second pinion 19b, is fixed to the robot body 1 as a further drive. U-shaped holders 15, which are also fixed to the robot body 1 via second ball joints 18b and are on both sides of the second nut 7b, prevent the second nut 7b from moving axially. The short threaded rod 14 does not include a groove, since the Cardan joints 21 prevent the short threaded rod 14 from rotating axially. The rotating second nut 7b moves the short threaded rod 14 in the U-shaped holders 15 and changes the left-right angle of the long threaded rod 2 of the robot leg by means of the Cardan joints 21, the plain bearings 20 and the frame 5.

[0050] Further linkages, similarly constructed, including short threaded rods and nuts rotated by pinions in U-shaped holders, are fixed to the lower edge of frame 5 at right angles to the linkages for side-to-side movement. These push the robot legs forward and backward.

[0051] Alternatively, any type of linear drive may be used for side to side and fore to aft movement.

[0052] Depending on the speed of the motor, a reduction gear may be required.

[0053] To improve the speed of movement, a rectangular rack may be used instead of a threaded rod, which eliminates the need for grooves to prevent axial rotation, improves the speed of movement, and otherwise requires a motor with a reduction gear or a stepper motor instead of a nut, gear wheel and simple motor for fine adjustment.

[0054] The robot leg may be disposed within the robot body, in which case the threaded rod 2 may extend through a continuous opening 22 in the robot body.

[0055] Fig. 4 shows a further exemplary embodiment of a mobile robot including a robotic leg. Fig. 5 shows a cross-sectional view of the mobile robot of Fig. 4 along section line AA.

[0056] In the exemplary embodiment, a long threaded rod 2 with an external thread and an axially extending groove 17 is used for the up and down movement. The threaded rod 2 passes through an opening 22 in the robot body 1, which has rounded edges and is slightly larger than the cross section of the threaded rod 2. The opening 22 in the robot body 1 may be continuous. In this case, the threaded rod 2 may extend through a continuous opening 22 in the robot body 1. Advantageously, the mobile robot may be configured in this way to be particularly compact. A U-shaped frame 5 is positioned below the opening 22, through which the threaded rod 2 moves axially.

[0057] Inside the frame 5, the spacer sleeve 4 is pressed against the threaded rod with its upper side facing the opening 22. The spacer sleeve 4 is rigidly connected to the frame 5 and forms a sliding bearing for the axial movement of the threaded rod 2. The threaded rod 2 extends through an opening in a first ball joint 18a. The robot leg is fixed to the robot body 1 via the first ball joint 18a. The first ball joint 18a allows the threaded rod 2 to move angularly together with the frame 5.

[0058] A first ball bearing 6a, configured to apply pressure, rests against the first ball joint 18a. The first ball bearing 6a is pressed against the threaded rod 2. The first ball bearing 6a rests against a first nut 7a, configured on the outside as a spur gear. This first nut 7a rests against a second ball bearing 6b, configured to apply axial pressure. A rotatable ring of the two ball bearings 6a, 6b rests against the nut 7a. The nut 7a can rotate freely in the frame 5. A long sleeve 10 rests against the ball bearing 6b. The long sleeve 10 extends through the frame 5 and is connected to the frame 5. The two sleeves 4, 10 connected to the frame prevent the first nut 7a from moving axially along the threaded rod 2 relative to the frame 5.

[0059] A motor 9 including a first pinion 19a is laterally fixed to the frame 5 as a first drive. The first pinion 19a engages with a gear wheel of a first nut 7a to rotate the gear wheel, thereby rotating the nut 7a and moving the threaded rod 2 within the frame 5. A first pin 12 fixed to the frame 5 engages in a groove in the threaded rod 2 so as not to rotate axially therewith.

[0060] Tension springs 3 at the upper corners of the frame 5 prevent the frame 5 from rotating radially about the threaded rod 2, allowing angular movement of the frame 5, and therefore the threaded rod 2, about the ball joint 18.

[0061] In the left-right movement, the two servo motors 23a, 23b are connected to the underside of the frame 5. The two servo motors 23a, 23b are each provided with an arm 24a, 24b that can rotate together with the associated servo motor 23a, 23b within an angular range 25a, 25b. The link mechanisms 13a, 13b are each movably connected to the arm 24a, 24b. The link mechanisms 13a, 13b are fixed to the robot body 1. Deflection of the arm 24a or 24b from the robot body 1 pulls the servo motor 23a or 23b towards the robot body 1, causing the frame 5 to rotate about the first ball joint 18a and tilting the threaded rod 2 outward. Since the link mechanisms 13a, 13b are arranged at approximately right angles to each other, the two servo motors 23a, 23b can move the threaded rod 2 in two horizontal dimensions.

[0062] The robot leg may be disposed within the robot body, in which case the threaded rod 2 may extend through a continuous opening 22 in the robot body. [Explanation of symbols]

[0063] 1 Robot body 2 Rod 3. Tension spring 4 Spacer sleeve 5 Frames 6a 1st ball bearing 6b 2nd ball bearing 7a First Nut 7b Second nut 8a Worm shaft 8b Worm shaft 9. Motor 10 Sleeve 11 Nut 12-pin 13 Link mechanism 13a First link mechanism 13b Second link mechanism 14 Short threaded rod 15 Holder 16 Drive unit 17 Axially extending groove 18a First ball joint 18b 2nd ball joint 19a 1st pinion 19b 2nd pinion 20 Plain bearing 21 Cardan joint 22 Opening 23a First servo motor 23b Second servo motor 24a 1st Arm 24b 2nd Arm 25a First angle range 25b Second Angle Range

Claims

1. A mobile robot comprising a robot body (1) and at least one robot leg, the robot leg comprising an axially movable rod (2) pivotally guided in the robot body (1), provided with means (6, 7a, 8a, 9, 10, 11) for axially moving the rod (2) and means (7b, 8b, 14, 15, 16) for pivoting the rod (2), an opening (22) is located at a location of the robot body (1) provided with respect to the robot leg, the rod (2) being movable in the opening vertically and at a variable angle relative to the opening.

2. 2. A mobile robot according to claim 1, characterized in that the opening (22) in the robot body (1) is continuous.

3. 3. The mobile robot according to claim 1, wherein the rod (2) is a first threaded rod comprising an external thread and an axially extending groove, the external thread engaging with an internal thread, the internal thread being connected to the robot body (1) in such a way that it can rotate and pivot but cannot move axially, a pin (12) being provided in the groove to prevent radial rotation of the rod (2), a first drive (9) rotating the internal thread of the rod (2) is provided as a means (6, 7a, 8a, 9, 10, 11) for moving the rod (2) axially, and at least one further drive (16) directly or indirectly connected to the first threaded rod is provided as a means (7b, 8b, 14, 15, 16) for pivoting the rod.

4. A mobile robot according to claim 1, 2 or 3, characterized in that two drives (16) connected directly or indirectly to the first threaded rod so as to be offset from one another are provided as means for pivoting the rod (2).

5. Mobile robot according to any one of the preceding claims, characterized in that the rod (2) is configured partially as a threaded rod.

6. A mobile robot according to any one of claims 1 to 5, characterized in that the rod (2) is preferably a rectangular rack, a drive including a complementary engagement element for engaging with the rack is provided as a means for axially moving the rod (2), and at least one further drive connected directly or indirectly to the rack is provided as a means for pivoting the rod.

7. A mobile robot according to any one of claims 1 to 6, further comprising a control device.

8. A mobile robot according to any one of the preceding claims, characterized in that it is provided with a tilt sensor.

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