AU2019100350A4

AU2019100350A4 - The hexapod robot with wheel type and leg type

Info

Publication number: AU2019100350A4
Application number: AU2019100350A
Authority: AU
Inventors: Bofei Ai; Yide Fang; Mengyao Guo; Yeqi Wei; Qing Zhu
Original assignee: Guo Mengyao Miss
Current assignee: Guo Mengyao Miss
Priority date: 2019-04-04
Filing date: 2019-04-04
Publication date: 2019-05-09
Anticipated expiration: 2027-04-04

Abstract

abstract The present invention relates to a hexapod robot which can be transformed by wheels. More specifically, a hexapod robot with an improved structure is involved. It can advance with the highest efficiency in rugged terrain, uneven surface, that is, common ground environment. The invention has innovative mechanicalstructure: wheels are not ordinary wheels, but integrated wheels and feet, that is, wheels are equivalent to 0-shaped feet when the wheels are locked, and rotate around the connection between wheels and body; wheels are equivalent to normal wheels when the wheels are unlocked and the motors in the connection between wheels and body are locked. The invention is suitable for fast and flexible walking in complex terrain. On the one hand, the foot state can adapt to rugged terrain; on the other hand, the wheel state can enable the robot to travel more quickly on flat terrain. The invention integrates the advantages of ordinary hexapod robot and automobile, but is superior to both. It is an improvement of ordinary hexapod robot. The robot is equipped with 12 12 12-volt DC motors, six of which are used to drive the rotation of the connector between the wheel and the car body. Each connector is equipped with a motor; the other six motors are allocated to six connectors to drive the rotation of six wheels. Twelve motors are controlled by L298N dual motor driver chip. The robot is powered by a 12V output battery of the 18650 model. Ultrasound sensors and chips working under 5V are supplied by DC-DC module in turn. The robot has two different sensors, including an ultrasonic sensor and a camera. HC-SRO4 ultrasonic sensor will be used. It can measure the distance between 2cm and 4m, and send the echo signal to Arduino (main board). The pulse width of the echo signal is proportional to the measured distance, so it can provide the distance information of the target obstacle. The invention applies six ultrasonic sensors, which are placed symmetrically on both sides with one angle of 20 degrees and one angle of 40, 60 and 80 degrees on one side, to solve the problem that the boundary information of surrounding obstacles can not be provided due to the ultrasonic divergence characteristics. In addition, the ultrasonic sensor should be combined with the camera. The camera uses KAIP ultra wide angle camera with 12V working voltage. Its advantages are wide angle and night vision. It ensures that the robot can collect the information of the surrounding environment well in various environments and feedback the information to the motherboard. All materials used in the manufacturing of the invention are easy to obtain, and the cost of manufacturing a complete set of wheel-set integrated robots is low. Fig.1

Description

THE HEXAPOD ROBOT WITH WHEEL TYPE AND LEG TYPE

Field of the invention

The present invention relates to a hexapod robot which can be transformed by wheels. More specifically, a hexapod robot with an improved structure is involved. It can advance with the highest efficiency in rugged terrain, uneven surface, that is, common ground environment.

BACKGROUNG OF THE INVENTION

In nature and human society, there are some places that humans cannot reach and special occasions that may endanger human life. Such as planetary surface, disaster mine, disaster prevention and rescue, and the fight against terrorism, etc., these dangerous environments are constantly explored and studied, seeking a feasible way to solve the problem has become the need of the development of science and technology and the progress of human society. Irregular terrain and rugged terrain are common features of these environments. So the application of wheeled robot and tracked robot is limited. Previous studies have shown that wheeled mobile way over relatively flat terrain, is the advantage of speed quickly and smoothly, also relatively simple structure and control, but when driving on uneven ground, will greatly increase energy consumption, and on soft ground or severe rugged terrain, the wheel moves will also serious loss of efficiency is greatly reduced.Compared with wheeled and tracked mobile robots, walking robots on bumpy roads have unique and superior performance. In this context, the research on multi-legged walking robots is booming. The appearance of bionic walking robot shows the advantage of walking robot. The legs of the hexapod walking robot have multiple degrees of freedom, which greatly enhances the flexibility of movement. It can keep the body level by adjusting the length of the legs and it can also adjust the position of the center of gravity by adjusting the length of the legs so that it is less prone to tipping over and more stable. However, there are still some problems in the development of hexapod robots. To solve the existing problems, our group has the following solutions. l.Poor flexibility and controllability and slow method: round foot together. Wheel robot foot fold line condition, speed of the robot is more agile, foot line condition wheel off the ground, travel is not affected by the ground, this design makes the robot line state, foot line, the wheels round on the foot switch function is more stable, more quickly. Secondly, the robot realizes the intellectualization on the state switch between wheel and foot. By processing the image captured by the robot, the robot can judge the road condition by itself when the environment changes, and then realize the intelligent switch of walking state. Easy to control the robot.2.Poor ability to avoid obstacles.In order to realize obstacle avoidance function of Hexapod robot, sensor and wireless control system must be used. Sensing system is designed on the hexapod robot to sense the distance of obstacles.

SUMMARY OF THE INVENTION

The invention has innovative mechanical structure: wheels are not ordinary wheels, but integrated wheels and feet, that is, wheels are equivalent to O-shaped feet when the wheels are locked, and rotate around the connection between wheels and body; wheels are equivalent to normal wheels when the wheels are unlocked and the motors in the connection between wheels and body are locked. The invention is suitable for fast and flexible walking in complex terrain. On the one hand, the foot state can adapt to rugged terrain; on the other hand, the wheel state can enable the robot to travel more quickly on flat terrain. The invention integrates the advantages of ordinary hexapod robot and automobile, but is superior to both. It is an improvement of ordinary hexapod robot. The robot is equipped with 12 12 12-volt DC motors, six of which are used to drive the rotation of the connector between the wheel and the car body. Each connector is equipped with a motor; the other six motors are allocated to six connectors to drive the rotation of six wheels. Twelve motors are controlled by L298N dual motor driver chip. The robot is powered by a 12V output battery of the 18650 model.

Ultrasound sensors and chips working under 5V are supplied by DC-DC module in turn. The robot has two different sensors, including an ultrasonic sensor and a camera. HC-SR04 ultrasonic sensor will be used. It can measure the distance between 2cm and 4m, and send the echo signal to Arduino (main board). The pulse width of the echo signal is proportional to the measured distance, so it can provide the distance information of the target obstacle. The invention applies six ultrasonic sensors, which are placed symmetrically on both sides with one angle of 20 degrees and one angle of 40, 60 and 80 degrees on one side, to solve the problem that the boundary information of surrounding obstacles can not be provided due to the ultrasonic divergence characteristics. In addition, the ultrasonic sensor should be combined with the camera. The camera uses KAIP ultra wide angle camera with 12V working voltage. Its advantages are wide angle and night vision. It ensures that the robot can collect the information of the surrounding environment well in various environments and feedback the information to the motherboard. All materials used in the manufacturing of the invention are easy to obtain, and the cost of manufacturing a complete set of wheel-set integrated robots is low. The advantages of the present invention lie in that it travels faster in complex terrain than other kinds of robots, so various additional devices can be installed on it according to user's needs to accomplish time-critical tasks in complex terrain, for example, life detector can be installed to carry out rescue and disaster relief work in post-earthquake ruins. Therefore, the invention has a larger development space, and can derive and invent robots with various functions on this basis.

DESCRIPTION OF THE DRAWINGS

The appended drawings are only for the purpose of description and explanation but not for limitation, wherein:

Fig.l and Fig.2 are side views of the present invention;

Fig.3 is a front view of the present invention;

Fig.4 is a lateral view of the present invention;

Fig.5,Fig.6 and Fig.7 are illustrations showing the scenario described in EXAMPLE 1 which shows how the invention can quickly pass through a soil slope in a wheeled state.

Fig.8, Fig.9, Fig.10 and Fig.11 are illustrations showing the scenario described in EXAMPLE 2 which shows how the invention can pass through steep terrain in a foot state.

DESCRIPTION OF PREFERRED EMBODIMENT

In order to make the present invention easier to understand, embodiments of the present invention will now be described with reference to the accompanying drawings.

Step A:

The main part of the robot is similar to a flat cuboid. The protruding part above the robot is in front, and the sensor is installed inside. Sensors include cameras and ultrasonic sensors. Camera sensors are used to judge the terrain, and the terrain is distinguished mainly by tortuosity. When the tortuosity is large, the robot chooses the foot state; when the tortuosity is small, the robot chooses the wheeled state. Ultrasound sensors are used to measure distances and control the speed of feet or wheels.

Step B:

The semi-circular device which inlays six wheels and connects the wheels to the car body becomes a connector. Connector and car body are connected by motor. The motor is in the car body. Each connector is equipped with a motor. There are six motors in total. These six motors can be locked. There is a mechanical lock between the connector and the wheel, similar to the brake device on the bicycle wheel. When the robot is in the foot state, the lock in the connector locks the wheel. At this time, the wheel can not rotate. Then, the motor between the connector and the car body is restarted. At this time, the wheel rotates around the axis of the motor, which is equivalent to the O-shaped foot. Six feet can move in triangular or wave gait on flat or steep ground.

Step C:

The wheel is a ring with gears on the inside, and each connector has a motor. The gears on the motor shaft engage with the gears on the inside of the wheel. When the robot is in the wheeled state, the lock in the connector is unlocked and the motor between the car body and the connector is locked. The motor in the connector runs, driving the gear to rotate, thus driving the wheel to rotate. When the wheel rotates, the friction between the wheel and the ground makes the wheel forward. Because the wheel is embedded in the connector, the forward movement of the wheel will push the connector and the car body. Thus, even if the wheel has no axis, the wheel can rotate and push the car body.

Example 1:

When the robot is facing the earth slope in front of it, the camera decides to adopt the wheeled state according to the principle of step A through image processing. Because the wheeled state allows the robot to pass through the soil slope at a faster speed. Because the slope is not steep, there is no need to adopt footwork.

The present invention aims to improve the hexapod robot so that it can flexibly switch the wheeled and footed states according to different terrain, select a more rapid and feasible travel mode, and can adapt to various complex terrain. In this example, a soil slope is built in the vrep simulation software to test the adaptability of the robot to such terrain when it travels in a wheeled state. After testing, the robot passed the slope very smoothly. This scenario is illustrated by Figs 5, 6 and7.

Example 2: But when a robot encounters a steep terrain, such as a ladder, it will choose the foot state according to the principle of Step 1. At this time, it is obvious that the robot can not move on the ladder in the wheeled state, and the foot state can be well adapted to this terrain, which embodies the advantages of the present invention, that is, the robot can flexibly adapt to various terrain, which is also the main purpose of the present invention. In order to test the adaptability of foot state to steep terrain, the following simulation is made. In this example, a step model is built in vrep by using MATLAB and vrep. In matlab, the robot is programmed and controlled to move on the step with wave gait. The simulation results show that the foot state can be well adapted to steep terrain. This scenario is illustrated by Fig. 8, Fig. 9, Fig. 10 and Fig. 11.

Claims

claim
1. A hexapod robot with wheel type and leg type, characterized in that: its mechanicalstructure comprises wheels which are integrated wheels and feet, specifically, wheels are equivalent to O-shaped feet when the wheels are locked, and rotate around the connection between wheels and body; wheels are equivalent to normal wheels when the wheels are unlocked and the motors in the connection between wheels and body are locked; said hexapod robot is suitable for fast and flexible walking in complex terrain: on the one hand, the foot state can adapt to rugged terrain; on the other hand, the wheel state can enable the robot to travel more quickly on flat terrain; said robot is equipped with 12 12 12-volt DC motors, six of which are used to drive the rotation of the connector between the wheel and the car body; each connector is equipped with a motor; the other six motors are allocated to six connectors to drive the rotation of six wheels; twelve motors are controlled by L298N dual motor driver chip; the robot is powered by a 12V output battery of the 18650 model; ultrasound sensors and chips working under 5V are supplied by DC-DC module in turn; said robot has two different sensors, including an ultrasonic sensor and a camera; HC-SR04 ultrasonic sensor will be used; it can measure the distance between 2cm and 4m, and send the echo signal to Arduino (main board); the pulse width of the echo signal is proportional to the measured distance, so it can provide the distance information of the target obstacle; said robot applies six ultrasonic sensors, which are placed symmetrically on both sides with one angle of 20 degrees and one angle of 40, 60 and 80 degrees on one side; the ultrasonic sensor is combined with the camera which uses KAIP ultra wide angle camera with 12V working voltage.