Amphibious robot

Abstract

The invention provides an amphibious robot. The amphibious robot comprises a robot body, a main controller arranged in the robot body, four driving assemblies fixed to the robot body at intervals and wheels fixed to the driving assemblies. The master controller is used for receiving the control signal to control the driving assembly, and the driving assembly is used for controlling the rotating speed and direction of the wheels. Compared with the prior art, the amphibious robot provided by the invention is more convenient in speed and angle control, and can be flexibly switched to run on water or land.

Description

Technical Field

[0001] The present invention is applicable to the technical field of robots, and in particular relates to an amphibious robot. Background Art

[0002] Amphibious robots combine the characteristics of underwater robots and land robots, and can switch freely between two completely different environments to perform various tasks. They usually use turbines, thrusters and propeller systems, as well as technologies such as sensors and cameras to detect and obtain relevant information.

[0003] The existing amphibious robots all use a structure of four wheels on the ground and two propellers on the water surface. The structure is complex, difficult to maintain, and does not support keeping the body level. The four wheels on the ground use ordinary waterproof motors, which have weak power, slow body speed, and cannot be flexibly controlled. Robots using double propellers cannot make quick turns or emergency stops due to the propellers. Existing products can no longer fully meet the requirements of amphibious robots for detection or transportation occasions that require strong power.

[0004] Therefore, a new amphibious robot is urgently needed to solve the above problems. Summary of the invention

[0005] The present invention provides an amphibious robot which can flexibly and stably switch between traveling on water and on land.

[0006] The present invention provides an amphibious robot, the amphibious robot comprising a body, a main controller respectively arranged in the body, four drive components fixed to the body at intervals, and wheels fixed to the drive components;

[0007] The main controller is used to receive a control signal to control the driving component, and the driving component is used to control the rotation speed and direction of the wheel.

[0008] Preferably, the driving assembly includes a motor and a servo, one end of the motor is fixedly connected to the wheel, the other end of the motor is fixedly connected to the servo, one end of the servo is fixedly connected to the fuselage body, the motor is used to control the rotation speed of the wheel, and the servo is used to control the direction of the wheel.

[0009] Preferably, the amphibious robot further comprises a FOC controller disposed in the body, and the FOC controller is used to control the rotation speed of the motor.

[0010] Preferably, the FOC controller comprises two, and each FOC controller is used to control two of the motors.

[0011] Preferably, the amphibious robot further comprises a power control panel disposed in the body.

[0012] Preferably, a gyroscope is provided in the main controller.

[0013] Preferably, when the amphibious robot moves on water, the following relationship is satisfied:

[0014]

[0015] Among them, throttle represents power, roll represents roll angle, pitch represents pitch angle, and power represents matrix operation synthesis.

[0016] Preferably, when the amphibious robot moves on water, its steering power satisfies:

[0017] throttle × tan(a) = turn;

[0018] Wherein, a represents the angle between the wheel and the horizontal plane, and turn represents the output steering force.

[0019] Preferably, the amphibious robot satisfies the following relationship when traveling:

[0020]

[0021] Among them, V represents the reference speed of the amphibious robot, V1, V2, V3 and V4 respectively represent the speed vectors of the wheels of the amphibious robot, α represents the steering angle, Lx represents the wheel spacing of the amphibious robot, and Lz represents the axle spacing of the amphibious robot.

[0022] Preferably, the fuselage body includes a bottom plate, a middle plate fixedly connected to one side of the bottom plate, and a top plate connected to the side of the middle plate away from the bottom plate; the four drive components are fixed at intervals on the outer peripheral side of the bottom plate, and the main controller is fixed inside the middle plate.

[0023] Compared with the prior art, the amphibious robot proposed in the present invention includes a body, a main controller respectively arranged in the body, four drive components fixed to the body at intervals, and wheels fixed to the drive components; the main controller is used to receive control signals to control the drive components, and the drive components are used to control the speed and direction of the wheels. In this way, the amphibious robot proposed in the present invention is more convenient in speed and angle control, and can flexibly switch between driving on water or land. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be described in detail below in conjunction with the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings. In the accompanying drawings:

[0025] Figure 1 is a schematic structural diagram of an amphibious robot provided by an embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of an amphibious robot provided by an embodiment of the present invention in a state of movement in water;

[0027] Figure 3 It is a schematic diagram of the structure of the underwater steering angle of the amphibious robot provided by an embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of an amphibious robot provided by an embodiment of the present invention moving on a land slope;

[0029] Figure 5 is a schematic structural diagram of an amphibious robot body provided by an embodiment of the present invention;

[0030] Figure 6 is a schematic diagram of wheel speed vectors of an amphibious robot provided by an embodiment of the present invention when traveling;

[0031] Figure 7 is a schematic structural diagram of an amphibious robot in a water traveling state provided by an embodiment of the present invention;

[0032] Figure 8 It is a schematic diagram of propeller distribution of the amphibious robot in the water driving mode provided by an embodiment of the present invention.

[0033] Fig. 9 is a schematic diagram of pitch angle analysis of an amphibious robot in a water traveling state provided by an embodiment of the present invention;

[0034] Fig.10 It is a schematic diagram of correction of the rolling angle of the servo of the amphibious robot in the water driving state provided by an embodiment of the present invention when the servo changes. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] Please refer to Figure 1-Figure 5The present invention provides an amphibious robot, the amphibious robot comprising a body 1, a main controller 2 respectively arranged in the body 1, four drive components 3 fixed to the body 1 at intervals, and wheels 4 fixed to the drive components 3;

[0037] The main controller is used to receive a control signal to control the driving component 3 , and the driving component 3 is used to control the rotation speed and direction of the wheel 4 .

[0038] Specifically, the amphibious robot adopts a very simple structure and can travel on water and land. The four-servo 32 and four-motor 31 structure adopted by the amphibious robot can provide powerful power for the robot. On the water surface, the servo 32 of the amphibious robot will fold up the four motors 31 and use the wheels 4 (which can be regarded as a four-rotor propeller with a rim on the outer side) to move forward, backward and turn. On land, the amphibious robot can unfold the four motors 31 and thus travel normally on land.

[0039] The amphibious robot can use a remote control to control the main controller 2 through the high-speed wireless transceiver SI24R1. The main controller 2 controls two FOC controllers 21, and one FOC controller 21 controls two motors 31. Using two controllers, four motors 31 can be controlled at the same time. At the same time, the main controller 2 monitors the current and voltage levels of the power control board to ensure the normal operation of the function. When the voltage control board sends an abnormal circuit, such as short circuit, overload, etc., it can also cut off the power supply in time to protect the robot controller. The posture of the amphibious robot, the four servos 32 and the motor 31 are controlled by the main controller 2, and a wireless remote control is provided. The remote control can adjust the speed, torque of each motor 31 and the control angle of the servo 32 at any time.

[0040] When the amphibious robot is in the land form, it will detect the Pitch angle detected by the gyroscope 22 in real time. Assuming the slope angle is a, the Pitch angle detected by the gyroscope 22 is a. After the angle a is converted through parameters, the rotation angles of the forward servo 32 and the rearward servo 32 are obtained, so that the body can be kept in a horizontal state.

[0041] When the amphibious robot moves in the water, when pitching, the lift difference between the front and rear wheels 4 is formed by changing the rotation speed of the front and rear wheels 4, such as when pitching forward, F3 = F4> F1 = F2, forming a certain torque on the front and rear symmetry axes of the fuselage, causing angular acceleration in the pitch direction, and the robot moves forward. When rolling, the lift difference between the front and rear wheels 4 is formed by changing the rotation speed of the left and right side wheels 4, such as Figure 2As shown in the figure, when rolling sideways, F2=F4>F1=F3, a certain torque is formed on the left and right symmetry axes of the amphibious robot, causing angular acceleration in the rolling direction, and the amphibious robot rolls. Through the combined action of pitch and roll motion, the amphibious robot can move freely in the water, and the amphibious robot can move quickly left and right in the water by controlling the angle of the rear wheels.

[0042] In this embodiment, the driving assembly 3 includes a motor 31 and a servo 32, one end of the motor 31 is fixedly connected to the wheel 4, the other end of the motor 31 is fixedly connected to the servo 32, one end of the servo 32 is fixedly connected to the fuselage body 1, the motor 31 is used to control the rotation speed of the wheel 4, and the servo 32 is used to control the direction of the wheel 4.

[0043] Specifically, when the amphibious robot moves from land to water, the posture of the motor 31 is switched by pressing a button on the remote control. At that time, the main controller 2 will fold the two steering gears 32 that are in the water, and increase the speed of the motor 31 to ensure that the front body of the amphibious robot can float normally. After the front body enters the water normally, the main controller 2 will fold the rear body into the water, and increase the speed of the rear wheels to ensure that the rear body of the amphibious robot can float normally at the same time.

[0044] In this embodiment, the amphibious robot further includes a FOC controller 21 disposed in the body 1 , and the FOC controller 21 is used to control the rotation speed of the motor 31 .

[0045] In this embodiment, the FOC controllers 21 include two, and each FOC controller 21 is used to control two motors 31 .

[0046] In this embodiment, the amphibious robot further includes a power control board 5 disposed in the body 1 .

[0047] In this embodiment, the main controller 2 is provided with a gyroscope 22. Specifically, the gyroscope 22 carried by the main controller 2 can be used not only when floating on water, but also on land. The folding angles of the four steering gears 32 are controlled by the Euler deflection angle of the gyroscope 22 to keep the robot level, so that the amphibious robot can transport items that can only be transported on a level road on land with a certain slope.

[0048] In this embodiment, when the amphibious robot moves on water, the following relationship is satisfied:

[0049]

[0050] Among them, throttle represents power, roll represents roll angle, pitch represents pitch angle, and power represents matrix operation synthesis. Specifically, when there is no controller input, the roll angle roll and pitch angle pitch tend to 0, so that the amphibious robot remains horizontal, and the buoyancy of the amphibious robot is increased or decreased by changing the throttle.

[0051] In this embodiment, when the amphibious robot moves on water, its steering power satisfies:

[0052] throttle × tan(a) = turn;

[0053] Wherein, a represents the angle between the wheel 4 and the horizontal plane, and turn represents the output steering force.

[0054] Specifically, since the four wheels are fixed on land and cannot be steered in the form of Ackerman steering angle like a car, the amphibious robot uses a four-wheel differential steering method for land driving. On this basis, the concept of a speed vector is introduced. The speed vector does not represent the actual speed, but the speed ratio of the four wheels. Normal vehicle control requires calculating the speed ratio of the four wheels at a certain turning angle.

[0055] If the amphibious robot rotates with a certain circle as the radius, the extension line of the front axle velocity vector intersects with the circle, and this intersection line is recorded as radius R2. Similarly, the extension line of the rear wheel velocity vector intersects with the circle, and this intersection line is recorded as R1. Taking the center of the circle as the starting point, the first velocity vector intersection point of the front axle is set to V2, and the second velocity vector intersection point is set to V1. The rear axle is represented by V4 and V3 in the same way. Lx represents the wheel spacing, and Lz represents the axle spacing. First, determine the relationship between V1 and V2, such as Figure 6 shown.

[0056] V2 and R1 can be expressed as:

[0057]

[0058] Substituting the R1 and R2 angle relationship equation 1-2 into equation 1-1, we can get:

[0059]

[0060] Simplifying, we get:

[0061] V1=V2+L x *tanα; (Formula 1-3)

[0062] Formula 1-3 is the ratio of the speed vectors of the two wheels on the front axle.

[0063] Similarly: V4 and R1 can be expressed as:

[0064]

[0065] Substituting the R1 and V3 angle relationship equation 1-5 into equation 1-4, we can get:

[0066]

[0067]

[0068] Simplifying, we get:

[0069] V3=V4+L X *tanβ; (Formula 1-6)

[0070] Therefore, it can be seen that when the front wheel group and the rear wheel group are on the same axis, the speed difference is the same.

[0071] At the same time, when α and β are equal, the lengths of the velocity vectors are equal, and the rear wheel steering speed should be equal to the front wheel speed ratio.

[0072] Right now:

[0073] V`4=V2+L z ; (Formula 1-7)

[0074] V`3=V1+L z ; (Formula 1-8)

[0075] Taking V2 as the speed reference, the actual speed ratio of V1:V2:V3:V4 is obtained from Formula 1-3, Formula 1-7 and Formula 1-8.

[0076] V+L x *tanα:V:V+L X *tanα+L z :V+L z ; (Formula 1-9)

[0077] Expressed in brackets:

[0078]

[0079] In equations 1-9 and 1-10, α is the steering angle and V is the reference speed.

[0080] For example, the Lx wheel spacing is 0.45 m, the Lz axle spacing is 0.5 m, the steering angles are 5 degrees, 15 degrees, and 20 degrees, and the reference speeds are 0.5, 1, 1.5, and 2. The calculation results are shown in Table 1 below.

[0081] Table 1 [Calculation results]

[0082]

[0083] The algorithm for driving on water is the same as that on land, but if you need to keep the vehicle level on the water, you need to use the horizontal body balance algorithm.

[0084] like Figure 7 As shown, when the horizontal body balance algorithm of the amphibious robot is enabled, the vehicle body will twist the four wheels by 90 degrees so that the internal propellers (i.e., wheels) are parallel to the water surface.

[0085] The pitch angle and roll angle of the vehicle body are read out by the sensor, and the distribution positions of the 4-axis propellers of the vehicle body are recorded as A, B, C, and D. Figure 8 shown.

[0086] First, we analyze the pitch angle as a single axis. Fw is the buoyancy generated by the propeller pushing the water, and F is the buoyancy actually exerted by the propeller on the vehicle body. Fig. 9 shown.

[0087] Depend on Fig. 9 It can be seen that when the pitch angle 0>0, propeller B is in a suspended or floating state, propeller B is disabled, and propeller A sinks and starts. The buoyancy provided by the current propeller is:

[0088] F θa =F wθa *cosθ; (Formula 1-16)

[0089] Similarly, if the pitch angle is 0<0, propeller A is in a suspended or floating state, propeller A is disabled, and propeller B sinks and starts. The buoyancy provided by the current propeller is:

[0090] F θb =F wθb *cosθ; (Formula 1-17)

[0091] The analysis method of roll angle is different from the above pitch angle analysis method. Because there are digital joint servos on the quadcopter, the system can feedback the changed value to the servo when the roll angle changes relative to the zero point, such as Fig.10 As shown in the figure, after the roll angle is corrected, the lift generated by the propeller can basically act on the buoyancy.

[0092] When the rolling angle λ>0, propeller C is in a suspended or floating state, propeller C is disabled, and propeller A sinks and starts. That is:

[0093] F λa =F wλa ; (Formula 1-19)

[0094] When the rolling angle λ is less than 0, propeller A is in a suspended or floating state, propeller A is disabled, and propeller C sinks and starts. That is:

[0095] F λc =F wλc ; (Formula 1-20)

[0096] The analysis method of propeller D is similar, and the power matrix is ​​formed according to the above formulas 1-16, 1-17, 1-19, and 1-20 as follows:

[0097]

[0098] Where Fp is the system holding power, and the four results of the matrix calculation represent the torque output of the four propellers respectively.

[0099] In this embodiment, the body 1 includes a bottom plate 11, a middle plate 12 fixedly connected to one side of the bottom plate 11, and a top plate 13 connected to the side of the middle plate 12 away from the bottom plate 11; the four drive assemblies 2 are fixed at intervals on the outer peripheral side of the bottom plate 11, and the main controller 3 is fixed in the middle plate 12. By dividing the body 1 into the bottom plate 11, the middle plate 12 and the top plate 13, the detachability of the amphibious robot is effectively improved, making assembly easier, and the body has better waterproof performance by being fixedly connected by rubber strips.

[0100] Compared with the prior art, the amphibious robot proposed in the present invention includes a body, a main controller respectively arranged in the body, four drive components fixed to the body at intervals, and wheels fixed to the drive components; the main controller is used to receive control signals to control the drive components, and the drive components are used to control the speed and direction of the wheels. In this way, the amphibious robot proposed in the present invention is more convenient in speed and angle control, and can flexibly switch between driving on water or land.

[0101] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0102] The embodiments of the present invention are described above in conjunction with the accompanying drawings. What is disclosed is only the preferred embodiment of the present invention. However, the present invention is not limited to the above-mentioned specific implementation manner. The above-mentioned specific implementation manner is only illustrative rather than restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms and equivalent changes without departing from the scope of protection of the purpose of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. An amphibious robot, characterized in that: The amphibious robot comprises a body, a main controller respectively arranged in the body, four drive components fixed to the body at intervals, and wheels fixed to the drive components; The main controller is used to receive a control signal to control the driving component, and the driving component is used to control the rotation speed and direction of the wheel.

2. The amphibious robot according to claim 1, characterized in that: The driving assembly includes a motor and a steering gear, one end of the motor is fixedly connected to the wheel, the other end of the motor is fixedly connected to the steering gear, one end of the steering gear is fixedly connected to the fuselage body, the motor is used to control the rotation speed of the wheel, and the steering gear is used to control the direction of the wheel.

3. The amphibious robot according to claim 2, characterized in that: The amphibious robot further includes a FOC controller disposed in the body, and the FOC controller is used to control the rotation speed of the motor.

4. The amphibious robot according to claim 3, characterized in that: The FOC controller includes two, and each FOC controller is used to control two motors.

5. The amphibious robot according to claim 1, characterized in that: The amphibious robot also includes a power control board arranged in the body.

6. The amphibious robot according to claim 1, characterized in that: A gyroscope is arranged in the main controller.

7. The amphibious robot according to claim 1, characterized in that: When the amphibious robot moves on water, the following relationship is satisfied: Among them, throttle represents power, roll represents roll angle, pitch represents pitch angle, and power represents matrix operation synthesis.

8. The amphibious robot according to claim 7, characterized in that: When the amphibious robot moves on water, its steering power satisfies: throttle × tan(a) = turn; Wherein, a represents the angle between the wheel and the horizontal plane, and turn represents the output steering force.

9. The amphibious robot according to claim 1, characterized in that: The amphibious robot satisfies the following relationship when traveling: Among them, V represents the reference speed of the amphibious robot, V1, V2, V3 and V4 respectively represent the speed vectors of the wheels of the amphibious robot, α represents the steering angle, Lx represents the wheel spacing of the amphibious robot, and Lz represents the axle spacing of the amphibious robot.

10. The amphibious robot according to claim 1, characterized in that: The fuselage body includes a bottom plate, a middle plate fixedly connected to one side of the bottom plate, and a top plate connected to the side of the middle plate away from the bottom plate; the four drive components are fixed at intervals on the outer peripheral side of the bottom plate, and the main controller is fixed inside the middle plate.

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