CN105148496B - A kind of skidding type based on gesture stability is ridden instead of walk robot - Google Patents

Abstract

The invention discloses a roller skating walking-replacing robot based on attitude control, which comprises left and right roller skating shoe bodies, a portable power supply, a communication control device and an attitude detection system. The roller skating shoe body has two four-wheel structures. There is a driving wheel at the left and right parts, and a small universal wheel at the front and rear parts. The driving wheel is driven by the motor to rotate to realize the omnidirectional movement of the roller skating shoe body. The 24V DC portable power supply provides electric drive for the roller skate body. The posture detection system obtains the upper body posture of the operator from the relative spatial relationship of six wireless motion capture sensors (WSSS) to identify its movement intention, and realizes it by adjusting the rotation speed of the driving wheel of the roller skating shoe body. The communication control device receives the WSSS sensor information and supplements the attitude algorithm to generate a speed command and sends it to the roller skate body controller to control the rotation of the driving wheel. The wheel-skating walking-replacing robot provides a tool integrating walking-replacing and entertainment functions for daily travel, and also provides a set of new control methods for the scooter.

Description

A wheel-skating walking robot based on attitude control

technical field

The invention belongs to the technical field of electric walking-replacing devices, and more particularly relates to a wheel-skating walking-replacing robot based on attitude control.

Background technique

Modern means of transportation is very developed, can realize by automobile, airplane for long-distance transportation, then has bicycle electric vehicle for broad masses to use for short-distance transportation. Today's transportation advocates green travel, so electric vehicles have developed rapidly due to their low-carbon environmental protection and non-human drive. The various electric scooters emerging on the market are the result of the development of such vehicles.

Electric roller skates are a cross product that combines electric scooter and roller skating. As a means of transportation, it also provides users with entertainment experience of roller skating.

In the Chinese invention patent application publication specification CN103263767A, a walking-replacing electric roller skate is disclosed, and the battery is loaded on the bottom of the shoe body. The shoe body is a three-wheel structure, the front two wheels are driving wheels, and the rear end is a ground wheel. The forward and backward speed is adjusted through the force of the foot on the pedal, and at the same time, the radial force is given to the ground wheel by swinging left and right to make the roller skates rotate.

The above-mentioned roller skates represent a common design and control method, but there are still deficiencies in the way of controlling the movement of roller skates by sensing the force of the feet through the force sensor. Regardless of the accuracy of the sensors, first of all, when people exercise on roller skates, the feet The force on the shoe will change with the movement, so the stable movement of the roller skates cannot be guaranteed; secondly, this type of electric roller skating needs to provide the radial force of the rear wheel through the action of the foot to change the direction of the roller skating, and this steering method is difficult to control accurately. Therefore, this type of electric roller skating control method based on force control does not achieve a complete walking function, and also requires the user to have certain experience in ordinary roller skating operations.

In the Chinese utility model patent specification CN202219076U, an electric roller skating device is disclosed. One improvement of the roller skating device is that the driving power supply and control unit of the electric roller skating are separated from the roller skating body, thereby providing a system structure to realize The control method other than force control simplifies the structure of roller skates at the same time. However, the connection of each unit in the patent is wired, so in actual use, the movement will be restricted due to the complexity of the wires.

Therefore, designing a simple in structure, safe and convenient electric roller skates will be the development trend of this type of product, and it will certainly provide greater convenience and entertainment for short-distance travel.

Contents of the invention

The present invention mainly aims to solve the problem of operational complexity caused by the control mode of electric roller skates controlled by the force of the feet, and proposes a roller-skating walking-replacing robot based on attitude control, which can replace electric roller skates and make them more convenient The utility model has the advantages of safety, convenient operation and simpler structure, and also provides a new strategy for the development of electric roller skates.

The wheel-skating type walking-replacing robot that the present invention proposes comprises:

Roller skating shoe body, there are two roller skating shoe bodies for users to operate with left and right feet. It is essentially a four-wheel mobile platform. There is a rubber-covered driving wheel with a diameter of 96mm on the left and right sides, and a small universal wheel installed on the front and rear. Inside the shoe body are the control circuit board and the drive circuit board. Through the circuit control, two graphite brush DC motors with digital encoders drive the left and right driving wheels to rotate. According to different speed combinations, the mobile platform can move forward, backward, left, and right. The roller skates are made of steel, and the overall mass is 5.8kg. While meeting the load requirements, it can also make the shoe body more reliable and easy to disassemble and repair.

The portable power supply is a rechargeable power supply, which can provide 24V voltage drive for the left and right roller skates. Its shape is a rectangular iron container, which is connected to the roller skates through two retractable spring power cables. The switch and the digital tube that can display the current voltage indication can remind the user to charge in time.

Control unit, the control unit is composed of ARM development board, which can send commands to the internal control circuit board of the roller skating shoe body to control the start/stop of the roller skating shoe body and the rotation of the driving wheel.

Furthermore, the attitude control of the walking roller skating robot can be realized through the wireless motion capture sensor (Wireless Standalone Sensing System, WSSS). The Euler angles of rotation relative to the earth coordinate system. Placing the WSSS sensor on the operator can judge the operator's upper body leaning forward/backward, turning posture, and the distance between the legs, thereby correspondingly changing the motion state of the wheel-skating walking robot to achieve attitude control.

Furthermore, WSSS transmits the Euler angle information to the control unit through 2.4G wireless technology, and obtains the motion control command of the roller skating shoe body through the calculation of the relevant information by the control unit, and uses the wireless Bluetooth serial port to transmit the control command to the internal control circuit of the roller skating shoe body .

Further, four linear pressure sensors are placed at the four corners of the roller skating body pedal to monitor the pressure distribution changes on the pedal in real time, and a corresponding signal conditioning circuit board is placed inside the roller skating shoe body to condition and input the pressure analog signal to the control circuit board to convert it into a digital signal , the pressure distribution information is obtained by processing the relevant digital information, so that the user's feet can be judged and the functions of system startup/shutdown and emergency braking can be realized.

The advantage of the roller skating walking-replacing robot is that it can realize the separation of the power supply and the roller skating shoe body, which is different from the power supply attached to the electric shoe, which can simplify the structure of the roller skating shoe body. The addition of wireless technology further simplifies the structure of the roller skating system. At the same time, the method of attitude control is used to replace the commonly used foot force control, so as to realize the complete walking function, which makes the control of the wheel-skating walking robot more precise and easier to operate, and is suitable for the entertainment and short-distance travel of the general public.

Description of drawings

Fig. 1 is the front schematic view of the body of the wheel-skating type walking-replacing robot of the present invention (remove the top floor mounting plate);

Fig. 2 is a side schematic diagram of the body of the wheel-skating walking-replacing robot of the present invention;

Fig. 3 is a schematic diagram of the back side of the roller skating shoe body of the roller skating type walking-replacing robot of the present invention (the bottom mounting plate is removed);

Fig. 4 is a schematic diagram of the top mounting plate and the bottom mounting plate of the roller skating type mobility robot roller skating shoe body of the present invention;

Fig. 5 is a schematic diagram of a portable power supply for a wheel-skating walking-replacing robot of the present invention;

Fig. 6 is a schematic diagram of the communication control device of the wheel-skating walking-replacing robot of the present invention, wherein (a) is the internal circuit structure and (b) is the shell structure;

Fig. 7 is a schematic diagram of the WSSS sensor used by the wheeled walking robot of the present invention;

Fig. 8 is the structural diagram of the control system of the wheel-skating walking-replacing robot of the present invention;

Fig. 9 is a schematic diagram of the WSSS attitude detection system used by the wheeled walking robot of the present invention;

10 is a schematic diagram of the roller skating walking-replacing robot of the present invention (a) the operator leaning forward/backward (b) the operator turning around (c) a schematic diagram of the turning mathematical model of the roller skating shoe body;

Figure 11 is a schematic diagram of the forward/backward movement of the roller skating robot roller skating shoe body of the present invention (a) normal state (b) abnormal state;

Fig. 12 is a program flow chart of the communication control center board of the roller skating type walking-replacing robot of the present invention;

Fig. 13 is a program flow chart of the roller skating shoe body control board of the roller skating walking-replacing robot of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

The body structure of the roller skating robot roller skating is shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4. The main frame of the roller skate is composed of a top mounting plate 1, a middle mounting plate 2 and a bottom mounting plate 3. Four sliding posts 4 are installed at the front four corners of the middle mounting plate 2 , and the top mounting plate 1 can be fixed on the sliding posts 4 by hexagonal screws. Four sensor mounting seats 5 are also installed at the four corners of the front of the middle mounting plate 2, and four-way pressure sensors can be fixed on the sensor mounting seats 5. In this design, the height of the sliding column 4 is slightly lower than that of the pressure sensor 6. The height on the seat 5 can make the operator's active force on the top floor mounting plate be completely distributed on the four-way pressure sensor 6 like this.

Bearing blocks 7 are installed at the front and rear ends of the middle mounting plate 2 back sides, and casters 8 are installed on the bearing blocks 7 as load-bearing universal wheels. A brushless DC motor 9 is installed near the load-bearing universal wheel, and constitutes a set of motor drive system with a reduction box and a gear box. A digital encoder 10 is installed at one end of the motor, and a motor coupling 11 is installed on the motor shaft at the other end, and the motor coupling 11 is a gear type structure. The DC brushless motor 9 is fixed on the back of the middle mounting plate through the motor mounting base 12 . Drive wheels 16 are installed on the left and right sides of the back side of the middle mounting plate 2, and are respectively fixed on the mounting plate by two drive wheel mounts 13. A driving wheel coupling 14 is installed on the driving wheel shaft and is fixed between the two driving wheel mounts 13. The driving coupling 14 is also a gear type structure. Therefore, the linkage of the motor 9 and the drive wheel 16 can be realized by putting the gear type crawler belt 15 on the motor coupling 11 and the drive wheel coupling 14, and the rotation speed of the drive wheel 16 can be controlled by controlling the motor rotation speed. The driving wheel 16 is wrapped with a rubber pad to increase the coefficient of friction and improve grip. In this design, the wheel bottom of drive wheel 16 and the wheel bottom of small foot load-bearing wheel 8 are designed on the same horizontal plane, so this roller skating type walking-replacing robot roller skating shoe body can be placed on flat ground stably.

The bottom mounting plate 3 can be fixed on the motor mounting base 12 and the driving wheel mounting base 13 by hex screws. A square cavity 17 is reserved in the middle part of the middle mounting plate 2 for placing the circuit system of the wheel-skating type walking-replacing robot. The circuit system consists of four circuit boards. From the top layer to the bottom layer are the power supply board, peripheral driver board, main control board and pressure signal conditioning board. It can be seen from Figure 1 and Figure 4 that the four pressure sensors are connected by signal lines On the signal conditioning board interface 18, the motor encoder 10 is connected to the peripheral drive circuit board interface 19, and the power supply board is connected to two system power supply lines 20 and is converted into a motor system, a circuit system and a pressure sensor through a voltage conversion circuit. powered by. The onboard ST series ARM microcontroller on the main control board can write embedded programs to control the peripherals of electric shoes. The circuit boards are fixed together by connectors, and are fixed on the bottom mounting plate 3 by copper pillars 21 and screws on the signal conditioning board. A hole 22 is left on the bottom mounting plate 3, and its function one is to draw the bluetooth serial line to be connected to the bluetooth serial port 23 attached on the base plate, and the other is to expose the JTAG interface 24 of the main control board for program download and debugging.

The above description is the structure of the left roller skate body, the mechanical structure of the right roller skate body is symmetrical to that of the left roller skate body, and the internal structure is completely consistent.

The portable power supply of the wheel-skating walking-replacing robot is shown in Figure 5, which is a power supply with a rectangular parallelepiped aluminum shell. The front panel of the power supply has two interfaces 25 which can provide two 24V DC drive voltages. The power switch 26 and digital tube 27 are placed in the center of the front panel to display the current voltage indication. If the voltage is insufficient, the power supply can be charged through the charging port 28. There are two handles 29 on the rear panel of the power supply to facilitate carrying, and it can be carried and used in a backpack. The power supply is connected to the system power supply lines 20 of the two roller skate bodies respectively through two spring power cords 30 to provide electric drive for the roller skates. The spring power cord 30 can be used to adjust the length of the power cord according to the height of the operator and the carrying position of the power supply. To achieve the purpose of multi-applicability.

The communication control device of this wheel-skating type walking-replacing robot is shown in Figure 6, and its appearance is a cuboid plastic box 31, and a set of communication system is installed inside after taking apart the box. The communication control center board 32 obtains the WSSS sensor receiver 33 through the serial port line to receive the attitude information frame, and forms a speed control command frame for controlling the left and right roller skates after processing and judging, and sends them to the left and right roller skate bodies respectively through the two Bluetooth serial ports 34 On the bluetooth serial port 23. The WSSS sensor receiver 33 uses 2.4G wireless communication technology to receive the signal of the external WSSS sensor 38 and convert it into a serial port information output. The entire communication system is driven by a mobile power supply 35 with a 5V output. If the power is insufficient, it can be disassembled and recharged. Several holes are left on the shell box of the communication control device to expose the antenna 36 and the Bluetooth serial port 34 of the WSSS receiver to improve signal strength, while leaving the JTAG interface 37 of the communication control center board for communication program download and debugging. When the communication control device is in use, it can be tied to the abdomen of the operator or placed in the backpack of the power supply.

The attitude detection device of the wheeled walking robot is shown in Figure 7. The figure shows a single WSSS sensor A1, and the entire attitude detection system has six WSSS sensors (A1, B1, C1, D1, E1, F1) with the same structure. , but the marker numbers are different to show the difference. The shape of the WSSS sensor is a cuboid plastic shell, which contains an attitude module chip integrating a three-axis acceleration sensor, a gyroscope, and a magnetic field strength sensor, a wireless transmission chip, and an internal power supply. The shell has a WSSS start switch 39 and communication/charging Interface 40, this interface has four connectors, two are +5V/GND interfaces for power supply, when the internal power indicator of the sensor shows that the power is insufficient, the sensor can be charged by a special charger; the other two are TX/RX serial port connectors, This enables the sensor to work in both wired and wireless modes. The coordinate system X-axis and Y-axis are drawn on the shell of the WSSS sensor. This coordinate system represents the coordinate system of the sensor itself, and its Z-axis direction can be obtained by the right-hand rule. The sensor can measure the rotational Euler angles (Roll, Pitch, Yaw) relative to the earth coordinate system at any posture in space, that is, the three coordinates around the sensor coordinate system after the sensor coordinate system coincides with the earth coordinate system The spatial attitude of the current sensor coordinate system can be obtained when the axis rotates the corresponding Euler angle. The WSSS sensor stores the Euler angle information in data frames and continuously sends information frames, and the WSSS receiver continuously receives such information frames and sends the Euler angle information to the control center board through the serial port.

The overall structure of the present invention and the relationship between the various devices are shown in Figure 8. Six WSSS sensors are tied to the designated body parts of the operator through sports bandages, and each sensor transmits data frames containing its posture information wirelessly without interruption. , the WSSS receiver installed inside the communication control device can receive these information frames, and transmit them to the communication control center board for processing through the serial port. After the posture information is processed, the speed command of the left and right roller skates is obtained and transmitted wirelessly through the Bluetooth serial port. When the Bluetooth serial port installed at the bottom of the roller skate body is paired with the Bluetooth serial port in the communication control device, the speed command can be received and transmitted to the roller skates control panel to execute commands. The portable power supply placed in the backpack provides electric drive for the left and right roller skating shoe bodies through the power cord.

As an embodiment of the present invention, we analyze the situation that the wheel-skating walking-replacing robot performs simple forward/backward movement. As shown in Figure 9, the six WSSS sensors in the attitude sensing system are fixed on the operator through the motion straps as shown in the figure, and the operator's action intention is determined by the relative relationship between the WSSS sensor F1 and D1 coordinate systems. In the judgment of forward/backward, the present invention intends to control the forward/backward movement of the roller skates respectively through the forward tilt/backward posture of the operator's upper body, and the greater the forward tilt/backward tilt, the faster the speed. When the operator stands upright When on roller skates, the speed is zero. As shown in Fig. 10(a), assuming that when the upper body of the operator leans forward, there is a distance between the Z-axis vector of the WSSS F1 sensor placed on the chest and the Z-axis vector of the WSSS D1 sensor placed on the abdomen in the plane formed by the two. an angle If it is set to a positive value, the angle is zero when the operator is standing upright, and is negative when the operator is leaning back. Therefore, the operator’s leaning forward and backward can be judged by the positive and negative values of the angle The posture and degree can further determine the forward and backward motion state of the roller skating shoe body. Taking the WSSS sensor coordinate system of the waist as the reference coordinate system, through a series of Euler angle rotations, the direction of the reference coordinate system can be consistent with the WSSS sensor coordinate system of the chest, and the included angle mentioned above is the reference coordinate system Roll angle to rotate around its X axis.

With the help of the Euler angle information output by the WSSS sensor, the rotation transformation matrix from the geodetic coordinate system to the WSSS sensor’s own coordinate system can be obtained. The pitch angle Roll around the X axis is φ, and the roll angle Pitch around the Y axis is θ. The heading angle Yaw rotating around the Z axis is ψ, and the Z-Y-X Euler angle is used to represent the space coordinate system, then the reference coordinate system is B, the current coordinate system is P, and the rotation matrix

Then, when calculating the Roll angle mentioned above, it is necessary to use the earth coordinate system as the transmission medium, namely: but The matrix form is the same as above, then the values of 3 rows and 1 column and 3 rows and 2 columns of the simultaneous matrix can be obtained to obtain the value of φ, that is, the included angle value.

In order to simplify the forward/backward model, the present invention sets the four driving wheels of the left and right roller skating shoe bodies to have the same speed when moving forward/backward, and the speed is proportional to the inclination angle. The specific implementation is: set the maximum forward speed for The maximum backward speed is The valid range for setting the included angle is And according to the actual situation, set the angle threshold as Then the forward/reverse speed determination expression is:

Program the formula and corresponding parameters into the controller program to obtain The size of the angle directly obtains the speed of the driving wheel in the state of forward/reverse motion.

As an embodiment of the present invention, we analyze the situation that the wheel-skating walking-replacing robot performs turning motion. The present invention intends to recognize the operator's steering intention through the relative positional relationship between the coordinate system of the WSSS sensor F1 and the D1 coordinate system. As shown in Figure 10(b), when the operator's upper body twists, the Z-axis of the chest WSSS sensor F1 and the Z-axis of the waist WSSS sensor D1 will generate an angle η on the horizontal plane, according to the positive and negative of the angle and the size Then the steering and degree of the upper body of the operator can be known. The present invention intends to design the steering control of the roller skating shoe body to be consistent with the steering of the upper body of the operator, that is, when the upper body of the operator turns left, the roller skating shoe body turns left, and when the upper body turns right, the roller skating shoe body turns right. When the steering degree of the upper body is small, keep going straight. Through observation, it can be found that the η angle is the Yaw angle that the WSSS D1 sensor rotates around its own Y axis to reach the WSSSF1 direction. According to the above analysis, it is the θ angle in the coordinate system rotation matrix, so it is the same as the measurement of the forward/backward angle. The method is similar, using the earth coordinate system as the medium, through the rotation matrix The value of 3 rows and 1 column can be directly obtained the size of θ angle.

As shown in Figure 10(c), the turning model of the roller skating shoe body is established. Taking the left turn as an example, the left and right roller skating shoe bodies are represented by two "work"-shaped geometric figures respectively. Let the roller skating shoe body width be 2d, and the left roller skating shoe body The speed of the left driving wheel of the body is v _2L , the speed of the right driving wheel is v _2R , the speed of the left driving wheel of the right roller skating shoe body is v _3L , the speed of the right driving wheel is v _3R , v ₂ is the speed of the center point of the left shoe, and v ₃ is the speed of the right The speed of the center point of the shoe, when the current relative position of the left and right roller skating shoes remains unchanged, that is, when the center distance a of the two roller skating shoes in the figure and the value of Δβ= _βr - _βl are kept constant, then according to the geometric characteristics, four The speeds of the driving wheels are: in In order to obtain the speed of the four driving wheels, all parameters in the above formula need to be measured.

For parameter a, this parameter is the distance between the two roller skating shoe bodies. When the operator stands on the roller skating shoe body according to the specified position, the distance between the operator’s legs can be used instead. It can be seen from Figure 9 that the remaining four parameters of the posture detection system The WSSS sensors are respectively placed on the left thigh, left calf, right thigh and right calf of the operator. If the distance between the two legs is to be measured, the coordinate system D1 of the waist WSSS sensor can be set as the reference coordinate system. When A1 After the coordinates of the origin of the E1 sensor in the D1 coordinate system, the distance between the A1 and E1 sensors, that is, the distance between the legs, can be calculated in the X-Z plane of the D1 coordinate system.

The translation change of space coordinate transformation is to move a certain distance along a certain coordinate axis of the current coordinate system to obtain a new coordinate system position, and the corresponding translation matrix is Therefore, taking the right leg as an example, it can be seen from Figure 9 that the Y-axis direction of the E1 sensor coordinate system is consistent with the direction of the calf, and the Y-axis direction of the C1 sensor coordinate system is consistent with the direction of the thigh, so the change from the E1 coordinate system to the D1 coordinate system The matrix is

Then the coordinates of the origin of E1 in the D1 coordinate system are seek the same reason then the distance between the legs

For the parameter β _l and parameter β _r , this parameter is the angle between the direction of the left and right roller skates and the X-axis of the reference coordinate system. When the Z-axis directions of the coordinate systems of the WSSS sensors A1 and E1 are respectively regarded as the direction of the roller skate body and When the coordinate system of WSSS sensor D1 is regarded as the reference coordinate system, the coordinate values of A1 and E1 in the respective coordinate systems of the Z-axis unit point in the D1 coordinate system coincident with the origin of A1 and E1 can be obtained by coordinate transformation method, Then obtain the corresponding included angle with the X-axis of the D1 coordinate system. For the parameter ∠a, this parameter is the angle between the line vector between the centers of the two roller skates and the reference coordinate system. This line vector can be obtained when calculating the distance between the legs, so the D1 coordinate system can be regarded as the reference coordinate system. Obtain the included angle parameter.

As an embodiment of the present invention, the turning motion can be perfected by combining the forward/backward motion of the roller skate body. Combining with Figure 10(c), taking the left turn as an example, when the operator’s upper body turns, an η angle will be generated between the Z-axis of the WSSS sensor F1 and D1, and a threshold value range [η _min η _max ] is given to the angle, which is smaller than the If it is within the range, it is judged as a left turn, if it is larger than this range, it is judged as a right turn, and if it is within this range, it is judged as no turning intention. The center speed of the roller skating shoe body in the driving wheel speed determination formula is determined by the previous motion state of the roller skating shoe body, that is, when the attitude detection system judges that the operator has steering intention, it must first judge whether the roller skating shoe body has forward/backward in the previous state The velocity of , that is, whether the velocity is zero at the same time. If it is not zero, this speed is given to the left driving wheel of the left roller skate body when turning left, and then the speeds of the other three driving wheels can be calculated; when turning right, this speed is given to the right driving wheel of the right roller skate body. If the speed in the previous state is zero, the operator intends to turn on the spot, so when turning left, set the left driving wheel of the left roller skate body to zero, and determine the right driving wheel of the left roller skate body according to the degree η angle deviates from the threshold range Speed, the greater the degree of deviation, the faster the speed. The speed of the two driving wheels of the right roller skating shoe body is still obtained by the formula of driving wheel speed; The speed of the left driving wheel of the roller skating shoe body, and then obtain the speed of the other driving wheels. As an example, assuming that the roller skates turn left, the speed v _2L of the left wheel of the left shoe is first determined, and the specific formula is:

Among them, K _t is the rotation scale coefficient, which is determined by experiment. If the roller skates turn right, the speed v _3R of the right wheel of the right shoe is determined first, and the determination formula is similar to the above formula.

The motion control strategies of the above three embodiments can satisfy the full range of actions of the present invention under normal conditions. In order to make the control effect more accurate, the operator needs to accurately place the sensor of the attitude detection system on the designated part of the body. Simultaneously, because this type of sensor is easily disturbed by magnetic fields, the present invention is not suitable for environments with strong magnetic fields.

As an embodiment of the present invention, we also need to consider a solution to the problem that the directions of the left and right roller skating shoe bodies are inconsistent during the forward/backward movement. If the roller skating body enters the forward/backward state, and the four driving wheels are given the same speed, the left and right roller skating bodies with inconsistent directions will inevitably collide, so it is necessary to constantly change their forward direction during the movement of the roller skates. This can be achieved by compensating the speed of the left and right drive wheels. As shown in Figure 11(b), it is only necessary to increase the speed of the left driving wheel of the right shoe to make the directions of the left and right roller skating shoes uniform again, as shown in Figure 11(a). The speed compensation is not a fixed value, and its size is related to the angle between the left and right roller skates and the distance between the two shoes. The formula for determining it is: The source of the parameters in the formula can be seen in Figure 10(c). The angle between the directions of the two shoes is equal to β _r -β _l , and the distance between the two shoes is a. The values of K ₁ , K ₂ , and K ₃ are determined by experiments. If necessary Can be adjusted.

As an embodiment of the present invention, the four-way pressure sensor placed under the top mounting plate of the roller skating shoe body has two functions: one is for robot start-up detection, and it needs to rely on the pressure sensor when the switches of the power supply, sensor and controller are closed. to detect whether someone is standing on the top mounting plate, and as shown in Figure 11, when the operator’s foot steps on the top mounting plate as shown in the figure, the four-way pressure sensor will be subjected to different forces. When the stepping position changes, the total force of the pressure sensor remains the same, but the proportion of the force distributed on different sensors changes. Therefore, by detecting the force ratio of the four-way pressure sensor, it can be judged whether the operator follows the normal stepping position as shown in Figure 11. Standing on the roller skating shoe body, if the specific gravity is not in the normal range, the roller skating mobility robot cannot be started until the operator adjusts the standing position correctly; the second is brake detection, when the operator wants to stop during driving When operating or in an emergency, when the foot leaves the upper mounting plate or moves to a position that deviates greatly from the standard position, the roller skate body will automatically stop working and the speed of the driving wheel will be set to zero. Regardless of whether it is a left roller skating shoe body or a right roller skating shoe body, as long as the four-way pressure sensor detects that the force is zero or the force distribution reaches an abnormal ratio, it can be judged that the system is in a braking state, and the entire robot will automatically stop working. The signal conditioning board in the circuit system inside the intermediate mounting plate can condition the four-way sensor signals into voltage signals that the control board can recognize, and obtain the digital value of the pressure signal through A/D conversion for program processing.

As shown in Figure 12, the program flow of the board in the communication control center reflects the workflow of the roller skating walking robot. The ultimate goal is to convert the information of the WSSS attitude sensor into the basis for controlling the movement of roller skates, that is, to achieve attitude control. . To further illustrate, the final speed determination formula of each driving wheel of the roller skating shoe body of the roller skating type mobility robot is: V=V _turn or (V _straight +V _compensate ), when the corresponding velocity component is calculated according to the flow chart in the figure, it can be obtained The final speed of the drive wheels. To further explain, the format of the attitude information frame sent by WSSS is as follows:

According to the label in the frame, the program can judge which WSSS sensor the frame is from. Further explanation, the format of the speed control command frame sent by the communication center control board is as follows:

Decimals will appear in the calculation of the speed of the driving wheel in the program, so in order to improve the accuracy, the decimal value needs to be reserved and transmitted to the roller skate body control board.

As shown in Figure 13, the program flow chart on the main control board of the roller skate body describes how the speed control command is executed inside the roller skate and the mechanism of the pressure sensor. Further explanation, since the roller skating shoe body uses a digital encoder to control the rotation of the DC motor, the digital PID control method can be used to stabilize the speed change process of the driving wheel, and the speed in the speed command frame is used as the expected value, and the current speed value is obtained through the digital encoder , the difference between the two is input to the incremental PID controller to form the speed feedback control, and the specified speed can be reached within 6.4ms.

Those skilled in the art can easily understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (10)

1. The utility model provides a roller skating formula robot of riding instead of walk based on attitude control which characterized in that includes two roller skates, portable power supply and communication control device, wherein:

the main framework of the roller skate is composed of a top layer mounting plate (1), a middle mounting plate (2) and a bottom mounting plate (3); the top mounting plate (1) is fixed on the middle mounting plate (2); four sensor mounting seats (5) are mounted at four corners of the front surface of the middle mounting plate (2), and four pressure sensors (6) can be fixed on the four sensor mounting seats (5); bearing seats (7) are arranged at the front end and the rear end of the back surface of the middle mounting plate (2), and casters (8) are arranged on the bearing seats (7) to serve as bearing universal wheels; a direct current brushless motor (9) is arranged near the bearing universal wheel, and the direct current brushless motor (9), a reduction box and a gear box form a set of motor driving system; one end of the direct current brushless motor (9) is provided with a digital encoder (10), and the other end of the direct current brushless motor (9) is provided with a motor coupling (11) on a shaft; the direct current brushless motor (9) is fixed on the back of the middle mounting plate (2) through a motor mounting seat (12); the left side and the right side of the back surface of the middle mounting plate (2) are provided with driving wheels (16) which are respectively fixed on the mounting plate (3) through two driving wheel mounting seats (13); a driving wheel coupling (14) is arranged on a driving wheel (16) shaft and is fixed between the two driving wheel mounting seats (13); the bottom mounting plate (3) is fixed on the motor mounting seat (12) and the driving wheel mounting seat (13); a square hollow hole (17) is reserved in the middle of the middle mounting plate (2) and used for placing a circuit system of the wheel-sliding type mobility robot; the circuit system consists of four circuit boards, a power supply board, an external drive board, a main control board and a pressure signal conditioning board are sequentially arranged from the top layer to the bottom layer, four paths of pressure sensors are connected to a signal conditioning board interface (18) through signal wires, a motor encoder (10) is connected to an external drive circuit board interface (19), and the power supply board is connected to two system power supply wires (20) and supplies power to the motor drive system, the circuit system and the pressure sensors through a voltage conversion circuit; the main control board carries ST series ARM microcontroller which can write in embedded program to control the electric shoe peripheral; the circuit boards are fixed together through a connector and fixed on the bottom mounting plate (3); a hole (22) is reserved on the bottom mounting plate (3), and the hole has the functions of leading out a Bluetooth serial port line to be connected to a Bluetooth serial port (23) attached to the bottom plate and exposing a JTAG interface (24) of the main control board for program downloading and debugging;

the front panel of the portable power supply is provided with two interfaces (25) which can provide two paths of 24V direct current driving voltage, a power switch (26) and a nixie tube (27) are arranged in the center of the front panel to display the current voltage reading, and if the voltage is insufficient, the power supply can be charged through a charging port (28); the back panel of the power supply is provided with two handles (29) which are convenient to carry and can be carried and used after being placed in a backpack; the power supply is respectively connected with the system power supply wires (20) of the two roller skate bodies through two spring power wires (30) to provide electric drive for the roller skates;

a control central board (32) in the communication control device obtains attitude information frames received by a WSSS sensor receiver (33) through a serial port line, and after processing and judgment, speed control command frames for controlling a left roller skate and a right roller skate are formed and are respectively sent to Bluetooth serial ports (23) on a left roller skate body and a right roller skate body through two Bluetooth serial ports (34); the WSSS sensor receiver (33) receives signals of an external WSSS sensor (38) by using a 2.4G wireless communication technology and converts the signals into serial port information output.

2. The attitude control-based roller skating type mobility scooter according to claim 1, wherein the WSSS sensor internally comprises an attitude module chip integrating a three-axis acceleration sensor, a gyroscope and a magnetic field intensity sensor, a wireless transmission chip and an internal power supply, and the housing is provided with a WSSS starting switch (39) and a communication/charging interface (40) which is provided with four connectors, two connectors are used as +5V/GND interfaces for supplying power, and the sensor can be charged by a special charger when the power indicator lamp in the sensor displays insufficient power; the other two are TX/RX serial ports, so that the sensor can work in a wired mode and a wireless mode; the WSSS sensor shell is provided with a coordinate system X axis and a coordinate system Y axis, the coordinate system represents the coordinate system of the sensor, and the Z axis direction of the coordinate system can be obtained by a right-hand rule; the sensor can measure the rotating Euler angle relative to a geodetic coordinate system when being in any attitude in space, namely the sensor coordinate system is coincided with the geodetic coordinate system and then rotates corresponding Euler angles around three coordinate axes of the sensor coordinate system to obtain the space attitude of the current sensor coordinate system; the WSSS sensor stores the Euler angle information on a data frame and continuously sends the information frame, and the WSSS receiver continuously receives the information frame and transmits the Euler angle information to the control central board through a serial port.

3. The attitude control-based roller-skating-type-mobility-assistant robot as claimed in claim 1 or 2, wherein four sliding columns (4) are installed at four corners of the front surface of the middle mounting plate (2), and the top mounting plate (1) can be fixed on the sliding columns (4) through hexagonal screws.

4. The attitude control-based roller-skating-type-scooter robot as claimed in claim 3, wherein the height of the sliding column (4) is slightly lower than the height of the pressure sensor (6) mounted on the sensor mounting seat (5), so that the force of the operator on the top mounting plate can be completely distributed on the four-way pressure sensor (6).

5. The attitude control-based roller-skating-type-mobility-assistance robot according to claim 1 or 2, wherein holes are formed in a case of the communication control device to expose an antenna (36) and a bluetooth serial port (34) of the WSSS receiver to improve signal strength, and a JTAG interface (37) of the communication control center board is formed for downloading and debugging of a communication program.

6. A posture-control-based wheeled walking assistant robot as set forth in claim 1 or 2, wherein six WSSS sensors are tied to the designated body part of the operator by means of a motion bandage, each sensor continuously and wirelessly transmits data frames containing posture information thereof, receives the information frames by means of a WSSS receiver installed inside the communication control device, and transmits the information frames to the communication control center board for processing through a serial port; the attitude information is processed to obtain speed commands of the left and right roller skate bodies and is wirelessly transmitted through the Bluetooth serial port, and when the Bluetooth serial port arranged at the bottom of the roller skate body is matched with the Bluetooth serial port in the communication control device, the speed commands can be received and transmitted to the roller skate control board to execute the commands; the portable power supply arranged in the backpack provides electric drive for the left and right roller skate bodies through the power cord.

7. An attitude control based wheeled walker as claimed in claim 1 or 2, wherein said pressure sensor is further configured to: the first method is robot starting detection, when switches of a power supply, a sensor and a controller are closed, whether a person stands on a top layer mounting plate or not is detected by a pressure sensor, when an operator steps on the top layer mounting plate in a set mode, four paths of pressure sensors can be subjected to acting forces with different sizes, if the stepping positions of the operator are changed, the total stress of the pressure sensors is unchanged, but the proportion of the acting forces distributed on the different sensors is changed, so that whether the operator stands on a roller skate body according to the set normal stepping position or not can be judged by detecting the stress specific gravity of the four paths of pressure sensors, if the specific gravity is not in a normal range, the roller skating type walking-replacing robot cannot be started until the operator correctly adjusts the standing position, and then the robot cannot be normally started; the second is brake detection, when an operator wants to stop operation in the running process or meets an emergency, the foot leaves the upper mounting plate or moves to a position greatly deviating from a standard standing position, the roller skate can automatically stop working, and the speed of the driving wheel is set to be zero; whether the left roller skate body or the right roller skate body is adopted, the system can be judged to be in a braking state as long as the four-way pressure sensor detects that the applied force is zero or the applied force distribution reaches an abnormal proportion, and the whole robot can be automatically stopped; the signal conditioning board in the circuit system in the middle mounting board can condition the four-way sensor signals into voltage signals which can be identified by the control board, and digital values of the pressure signals are obtained through A/D conversion and are used for program processing.

8. An attitude control-based wheeled robot scooter as claimed in claim 1 or 2, wherein said communication control means calculates a forward/backward speed V in a straight-ahead situation_straightThe expression of (a) is:

the pitch angle rotating around the X axis can be obtained by programming the formula and the corresponding parameters into a controller programThe angle is directly determined by the speed of the driving wheel in the forward/backward movement state, wherein settingIn order to be the maximum value of the forward speed,is the maximum speed of the backward movement,the effective range of the included angle is,the included angle threshold is set according to actual conditions;

when the left and right roller skate bodies are not consistent in direction in the forward/backward movement, the communication control device correspondingly increases the speed of the left driving wheel of the right shoe to enable the directions of the left and right roller skate bodies to be unified again, and the calculation formula is as follows:wherein the values of K1, K2 and K3 are determined by experiments, β_r-β_lIs an included angle between two shoe directions, and a is a distance between two shoes;

the final speed formula for each drive wheel is: v is V_straight+V_compensate。

9. An attitude control-based wheeled robot as claimed in claim 1 or 2, wherein said communication control means calculates the speeds of the four drive wheels in a turning situation as:

$v_{2L}=v_2(1-\frac{dsin({\mathrm{\β}}_r-{\mathrm{\β}}_l)}{\left|a\right|{\mathrm{sin\θ}}_r})$

$v_{2R}=v_2(1+\frac{dsin({\mathrm{\β}}_r-{\mathrm{\β}}_l)}{\left|a\right|{\mathrm{sin\θ}}_r})$

$v_{3L}=v_3(1-\frac{dsin({\mathrm{\β}}_r-{\mathrm{\β}}_l)}{\left|a\right|{\mathrm{sin\θ}}_l})$

$v_{3R}=v_3(1+\frac{d\sin ({\mathrm{\β}}_r-{\mathrm{\β}}_l)}{\left|a\right|{\mathrm{sin\θ}}_l})$

wherein,setting the width of the roller skate body as 2d, v_2LIs the left driving wheel speed v of the left roller skate body_2RFor the right driving wheel speedDegree, v_3LThe speed v of the left driving wheel of the right roller skate body_3RIs the right driving wheel speed, v₂Velocity of the center point of the left shoe, v₃The speed of the right shoe center point, a is the distance between the centers of the two-wheeled skate bodies, β_r-β_lIs an included angle between the two shoe directions.

10. The attitude control-based roller-skating-type-scooter robot according to claim 1 or 2, wherein the communication control device has an external shape of a rectangular parallelepiped plastic box.