A centroid offset type spherical robot based on double-wheel driving principle

Abstract

The application provides a centroid offset type spherical robot based on a double-wheel driving principle and belongs to the field of spherical robots. The robot can solve the problems of uncontrollable robot posture and lost motion control precision caused by slippage between an internal driving unit of the spherical robot and an inner wall of a spherical shell. The robot comprises a spherical shell, a pulley, a wheel assembly, a battery, a circuit board, a lower plate assembly, an eccentric assembly, an upper plate and a posture sensor. The lower plate assembly is arranged directly below the upper plate. The edge of each pulley is in contact with the inner wall of the spherical shell. The two wheel assemblies are symmetrically arranged on the lower end surface of the upper plate. The eccentric assembly is arranged on the rear side of the lower end surface of the upper plate and used for changing the gravity center of the robot. The wheel assembly is used for driving the robot to move. The wheel assembly comprises a wheel and a motor. The output end of the motor is connected with the wheel. The lowest point of the outer edge of the wheel is in contact with the inner wall of the spherical shell. The robot is mainly used for detection in a harsh environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of spherical robots, in particular to a centroid offset type spherical robot based on double-wheel driving principle. BACKGROUND

[0002] The spherical robot is a fully enclosed robot with a spherical shell, which can realize movement through centroid offset or momentum conservation principle. This kind of robot has good sealing property, strong balance and high motion flexibility, can realize omnidirectional rolling, has good obstacle crossing function, and if the robot is hit or falls from a high place, the spherical shell makes it easy to adjust and restore the motion posture. Therefore, the spherical robot can work in wet, dusty and rugged complex environments, and can be used in military reconnaissance, planet exploration, post-disaster search and rescue and pipeline detection tasks.

[0003] The driving principle of the spherical robot is to break the static balance of the sphere through the movement of the internal driving unit, so as to realize the rolling movement of the robot.

[0004] At present, there are two main kinds of motion principles for spherical robots. One is to realize movement under the action of gravity torque through centroid offset; the other is to ensure that the centroid of the robot is always located directly above the ground contact point, so that the gravity torque at the contact point is zero, and the robot moves based on the principle of angular momentum conservation. Since the control method of centroid offset type spherical robot is simpler and the motion form is more intuitive and clear, most of the spherical robots currently use the motion principle of centroid offset.

[0005] During the movement of the spherical robot, the existence of the spherical shell makes the contact area between the robot and the ground small. If the internal driving structure of the spherical robot does not contain a corresponding posture adjusting device, it cannot guarantee that the sphere can move along the specified path during movement. The existing double-wheel driven spherical robot mostly uses double-wheel differential to realize the adjustment of the heading direction of the spherical robot. This adjustment method has hysteresis, and requires that the contact force between the internal driving unit and the spherical shell be sufficient. If the internal driving unit and the inner wall of the spherical shell slip during the movement of the robot due to complex environment, the posture of the robot cannot be controlled and the motion control precision is lost. SUMMARY

[0006] Therefore, the present application aims to provide a centroid offset type spherical robot based on double-wheel driving principle to solve the problems of uncontrollable robot posture and loss of motion control precision caused by slippage between the internal driving unit and the inner wall of the spherical shell of the spherical robot.

[0007] In order to achieve the above object, the application adopts the following technical scheme: a centroid offset type spherical robot based on double-wheel driving principle, comprising a spherical shell, a pulley, a wheel assembly, a battery, a circuit board, a lower layer plate assembly, an eccentric assembly, an upper layer plate and a posture sensor, the lower layer plate assembly is arranged directly below the upper layer plate, a plurality of pulleys are arranged on the upper end surface of the upper layer plate in a circumferential direction, the rims of each pulley are in contact with the inner wall of the spherical shell, the battery is arranged on the upper end surface of the lower layer plate assembly, the circuit board is connected with the lower layer plate assembly and arranged above the battery, the wheel assembly is provided with two, the two wheel assemblies are arranged on the lower end surface of the upper layer plate in a left-right symmetrical manner and above the circuit board, the wheel assembly, the circuit board, the eccentric assembly and the posture sensor are electrically connected with the battery, the wheel assembly, the eccentric assembly and the posture sensor are electrically connected with the circuit board, the eccentric assembly is arranged on the rear side of the lower end surface of the upper layer plate and used for changing the gravity center of the robot, and the wheel assembly is used for driving the robot to move.

[0008] Furthermore, the eccentric assembly comprises a weight, a rudder support, a half-arm rudder arm and a rudder, one end of the weight is connected with the half-arm rudder arm, the other end of the half-arm rudder arm is connected with the rotating end of the rudder, the rudder is connected with the rudder support, the rudder support is connected with the rear side of the lower end surface of the upper layer plate, the rudder is electrically connected with the battery, and the rudder is electrically connected with the circuit board.

[0009] Furthermore, the motor is a direct-current speed reduction motor.

[0010] Furthermore, each pulley is rotationally connected with a pulley connecting piece, the lower end of the pulley connecting piece is connected with the upper end surface of a sheet, and the sheet is connected with the upper layer plate.

[0011] Furthermore, the lower layer plate assembly comprises a lower layer plate and a first connecting piece, four first connecting pieces are arranged at the four corners of the lower layer plate, and the upper end of each first connecting piece is connected with the upper layer plate.

[0012] Furthermore, the spherical shell, the lower layer plate, the upper layer plate and the sheet are all made of acrylic material.

[0013] Furthermore, the four corners of the circuit board are connected with the upper end surface of the lower layer plate through a second connecting piece.

[0014] Furthermore, the output end of the motor is connected with the wheel through a shaft coupling.

[0015] Furthermore, the wheel comprises a sponge inner tube and a rubber outer tube which are connected with each other.

[0016] Further, the wheel assembly further comprises a motor support, the motor support comprises a horizontal part and a vertical part which are connected perpendicularly to each other, the motor support is connected with the vertical part, and the horizontal part is connected with the upper layer plate through a third connecting piece.

[0017] Compared with the prior art, the application has the beneficial effects that:

[0018] 1. During the movement of the robot, the two side wheels have a large friction force with the inner wall of the spherical shell, the spherical shell is not easy to slip during being driven to move, the energy utilization rate is high, and the robot is more energy-saving.

[0019] 2. The robot can improve the stability of the robot by setting the relatively heavy components such as the battery and the circuit board at the lower position.

[0020] 3. The lower layer plate and the upper layer plate of the robot are made of acrylic material which is easy to process, when installing different types of sensors and driving units, the lower layer plate and the upper layer plate do not need to be redesigned, and only need to be re-drilled to realize the installation and fixation of new components.

[0021] 4. The robot can reduce the shaking of the internal components of the spherical shell and improve the stability of the robot by setting the pulley in close contact with the inner wall.

[0022] 5. The robot can quickly restore stability when it shakes by setting the posture sensor in cooperation with the eccentric component. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application. The embodiments of the application illustrated in the drawings, and their description, are presented to add generic structure and understanding of the application. In the drawings:

[0024] Figure 1 It is a front view of a centroid offset type spherical robot based on a double-wheel driving principle according to the application;

[0025] Figure 2 It is a side view of the internal components of the spherical shell of a centroid offset type spherical robot based on a double-wheel driving principle according to the application;

[0026] Figure 3 It is a perspective structural schematic view of the internal components of the spherical shell of a centroid offset type spherical robot based on a double-wheel driving principle according to the application.

[0027] Ball shell 1; pulley 2; wheel 3; shaft 4; motor 5; battery 6; lower plate 7; circuit board 8; motor support 9; weight 10; upper plate 11; pulley connector 12; sheet 13; rudder support 14; half-arm rudder arm 15; rudder 16; attitude sensor 17. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present application, not all the embodiments.

[0029] Referring to the accompanying drawings, a centroid offset type spherical robot based on a double-wheel driving principle includes a spherical shell 1, a pulley 2, a wheel assembly, a battery 6, a circuit board 8, a lower plate assembly, an eccentric assembly, an upper plate 11, and an attitude sensor. The lower plate assembly is arranged directly below the upper plate 11. The upper end surface of the upper plate 11 is uniformly provided with a plurality of pulleys 2. The rim of each pulley 2 is in contact with the inner wall of the spherical shell 1. The battery 6 is arranged on the upper end surface of the lower plate assembly. The circuit board 8 is connected to the lower plate assembly and arranged above the battery 6. The wheel assembly is provided with two parts, which are arranged symmetrically on the lower end surface of the upper plate 11 and above the circuit board 8. The wheel assembly, the circuit board 8, the eccentric assembly, and the attitude sensor are electrically connected to the battery 6. The wheel assembly, the eccentric assembly, and the attitude sensor are electrically connected to the circuit board 8. The eccentric assembly is arranged on the rear side of the lower end surface of the upper plate 11 to change the center of gravity of the robot. The wheel assembly is used to drive the robot to move. The wheel assembly includes a wheel 3 and a motor 5. The output end of the motor 5 is connected to the wheel 3. The outer rim of the wheel 3 is in contact with the inner wall of the spherical shell 1.

[0030] In the embodiment, the eccentric assembly comprises a weight 10, a rudder support 14, a half-arm rudder arm 15 and a rudder 16, the weight 10 is connected with one end of the half-arm rudder arm 15, the other end of the half-arm rudder arm 15 is connected with a rotating end of the rudder 16, the rudder 16 is connected with the rudder support 14, the rudder support 14 is connected with a rear side of a lower end surface of the upper plate 11, the rudder 16 is electrically connected with the battery 6, and the rudder 16 is electrically connected with the circuit board 8. The signal of the posture sensor is transmitted to the circuit board 8, the circuit board 8 controls the rudder 16 to operate, the rudder 16 operates to drive the half-arm rudder arm 15 to move, and the half-arm rudder arm 15 drives the weight 10 to move, so that the position of the weight 10 is adjusted according to the posture of the robot at this time, and the robot is quickly stabilized. The weight 10 is made of metal iron. The rudder support 14 is a right-angle 3D printed part, the horizontal part of the 3D printed part is connected with the lower end surface of the upper plate 11, and the vertical part of the 3D printed part is connected with the rudder 16. The battery 6 is a 3S model airplane lithium battery.

[0031] In the embodiment, the motor 5 is a DC speed reduction motor.

[0032] In the embodiment, each of the pulleys 2 is rotationally connected to a pulley connecting piece 12, the lower end of the pulley connecting piece 12 is connected with the upper end surface of a sheet 13, and the sheet 13 is connected with the upper plate 11. The sheet 13 is made of acrylic material and is easy to process, a plurality of threaded holes are processed on the sheet 13, and corresponding threaded holes are processed on the upper plate 11, so that the position of the pulley 2 can be changed by changing the position of the sheet 13, so that the pulley 2 is more closely attached to the inner wall of the spherical shell 1, and the stability of the components in the spherical shell 1 is better. The pulley 2 is a plastic-coated pulley.

[0033] In the embodiment, the lower plate assembly comprises a lower plate 7 and a first connecting piece, four first connecting pieces are arranged at the four corners of the lower plate 7, and the upper end of each first connecting piece is connected with the upper plate 11. Through the four first connecting pieces, the stability of the connection between the upper plate 11 and the lower plate 7 can be increased.

[0034] In the embodiment, the spherical shell 1, the lower plate 7, the upper plate 11 and the sheet 13 are all made of acrylic material. The acrylic material is easy to process, can increase the convenience of assembly and replacement of internal components, and the spherical shell 1 is made of acrylic material with certain mechanical strength, which is convenient for protecting the internal parts from damage in harsh environments.

[0035] In the embodiment, the four corners of the circuit board 8 are connected to the upper end surface of the lower plate 7 through a second connecting piece.

[0036] In this embodiment, the output end of the motor 5 is connected with the wheel 3 through the shaft 4.

[0037] In this embodiment, the wheel 3 comprises a sponge inner tube and a rubber outer tube connected with each other. The rubber outer tube is made of soft rubber, which can improve the friction with the inner wall of the spherical shell 1, so as to prevent the occurrence of the slip phenomenon.

[0038] In this embodiment, the wheel assembly further comprises a motor support 9, the motor support 9 comprises a horizontal part and a vertical part connected with each other vertically, the motor support 9 is connected with the vertical part, and the horizontal part is connected with the upper layer plate 11 through a third connecting piece.

[0039] The first connecting piece, the second connecting piece and the third connecting piece are all copper columns, and copper columns with different lengths and diameters are selected according to actual use conditions. Through the setting mode of the copper columns, when the internal driving assembly and other parts are changed, only the corresponding positions of the lower layer plate 7 and the upper layer plate 11 need to be drilled and then the copper columns are inserted for connection, without the need to redesign or replace the lower layer plate 7 and the upper layer plate 11, only the punching treatment needs to be re-performed.

[0040] The circuit board 8 comprises two parts of a control circuit and a power supply circuit, the control circuit mainly comprises a main control chip STM32F103C8T6, a Bluetooth module HC05, an attitude sensor (model 17) MPU6050, and a motor driving module BTN7971, and the power supply circuit mainly comprises two types of voltage stabilizing chips, including an LM2596-5 capable of stabilizing 5V voltage and an AMS1117-3.3 capable of stabilizing 3.3V voltage.

[0041] In use, the motor 5 operates to drive the shaft 4 to rotate, the shaft 4 rotates to drive the wheel 3 to rotate, the wheel 3 rotates to break the balance state of the robot, so as to drive the spherical shell 1 to move, thereby realizing the movement of the robot. Two motors 5 can realize the omnidirectional movement function of the spherical robot by using the differential principle.

[0042] The signals of the attitude sensor are transmitted to the circuit board 8, the circuit board 8 controls the steering gear 16 to operate, the steering gear 16 operates to drive the half-arm steering gear arm 15 to move, the half-arm steering gear arm 15 drives the weight 10 to move, so as to adjust the position of the weight 10 according to the posture of the robot at this time, thereby quickly stabilizing the robot.

[0043] The sensors, controllers, circuits and control programs that can be used in the application are all prior art, and will not be described here.

[0044] The above disclosed embodiments of the present application are only used to help explain the present application. The embodiments do not describe all the details of the present application, and the present application is not limited to the specific embodiments described. According to the content of the present specification, many modifications and changes can be made. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application.

Claims

1. A spherical robot with a center-of-gravity shift based on the dual-wheel drive principle, characterized in that: The system includes a spherical shell (1), pulleys (2), wheel assemblies, a battery (6), a circuit board (8), a lower plate assembly, an eccentric assembly, an upper plate (11), and an attitude sensor. The lower plate assembly is located directly below the upper plate (11). Multiple pulleys (2) are evenly distributed around the circumference of the upper surface of the upper plate (11), and the rim of each pulley (2) is in contact with the inner wall of the spherical shell (1). The battery (6) is located on the upper surface of the lower plate assembly. The circuit board (8) is connected to the lower plate assembly and located above the battery (6). There are two wheel assemblies, which are arranged symmetrically on the upper plate. The wheel assembly, circuit board (8), eccentric assembly, and attitude sensor are all electrically connected to the battery (6) on the lower end surface of the upper plate (11) and above the circuit board (8). The wheel assembly, eccentric assembly, and attitude sensor are all electrically connected to the circuit board (8). The eccentric assembly is located on the rear side of the lower end surface of the upper plate (11) to change the robot's center of gravity. The wheel assembly is used to drive the robot's movements. The wheel assembly includes a wheel (3) and a motor (5). The output end of the motor (5) is connected to the wheel (3). The lowest point of the outer rim of the wheel (3) is in contact with the inner wall of the spherical shell (1). The core assembly includes a weight (10), a servo bracket (14), a half-arm servo arm (15), and a servo (16). The weight (10) is connected to one end of the half-arm servo arm (15), and the other end of the half-arm servo arm (15) is connected to the rotating end of the servo (16). The servo (16) is connected to the servo bracket (14), and the servo bracket (14) is connected to the rear side of the lower end face of the upper plate (11). The servo (16) is electrically connected to the battery (6) and the circuit board (8). The lower plate assembly includes a lower plate (7) and a first connector, the first connector being provided with... Four, four first connectors are set at the four corners of the lower plate (7), and the upper end of each first connector is connected to the upper plate (11). The four corners of the circuit board (8) are respectively connected to the upper surface of the lower plate (7) through a second connector. The wheel assembly also includes a motor bracket (9). The motor bracket (9) includes a horizontal part and a vertical part that are perpendicularly connected to each other. The horizontal part is connected to the vertical part. The horizontal part is connected to the upper plate (11) through a third connector. The first connector, the second connector and the third connector are all copper pillars. The wheel (3) includes a sponge inner tube and a rubber outer tube that are connected to each other.

2. The centroid-shifting spherical robot based on the dual-wheel drive principle according to claim 1, characterized in that: The motor (5) is a DC geared motor.

3. A centroid-shifting spherical robot based on a dual-wheel drive principle according to claim 1, characterized in that: Each of the pulleys (2) is rotatably connected to the pulley connector (12), the lower end of the pulley connector (12) is connected to the upper end face of the sheet (13), and the sheet (13) is connected to the upper plate (11).

4. A centroid-shifting spherical robot based on a dual-wheel drive principle according to claim 3, characterized in that: The spherical shell (1), lower plate (7), upper plate (11) and sheet (13) are all made of acrylic material.

5. A centroid-shifting spherical robot based on a dual-wheel drive principle according to claim 1, characterized in that: The output end of the motor (5) is connected to the wheel (3) via a coupling (4).

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