CN106621318B - A joystick system and method for collecting signals based on sensor mpu6050 - Google Patents

Abstract

The invention relates to a handle rocker system and a method based on signals collected by a sensor mpu6050, belonging to the field of handles. The method comprises the following steps: signal acquisition module, wireless transceiver module, GPIO button module, power voltage stabilizing module and pressure measuring module, signal acquisition module respectively with wireless transceiver module, GPIO button module, power voltage stabilizing module and pressure measuring module are connected, signal acquisition module includes microprocessor K60 and rocker device, wireless transceiver module includes the NRF24L01 wireless radio frequency module of being connected with microprocessor K60, GPIO button module includes outside button and LED pilot lamp, power voltage stabilizing module includes battery and steady voltage chip LM-2596, pressure measuring module includes voltage comparator LM 301A. The beneficial effects are that: the invention can obtain better dynamic performance and static performance, and obtain higher accuracy, stability and comfort, thereby obtaining better user experience.

Description

A joystick system and method for collecting signals based on sensor mpu6050

technical field

The invention relates to the field of handles, in particular to a handle rocker system and method for collecting signals based on a sensor mpu6050.

Background technique

With the continuous progress of today's social economy and the development of science and technology, people's daily entertainment methods are becoming more and more abundant. Among them, electronic games and drones are relatively common entertainment items, especially drones have been welcomed and loved by more people as an emerging entertainment method, both of which need to be operated with handles, and high-precision joystick handles Can enable users to obtain a better experience. Most of the traditional joysticks on the market currently use potentiometers as angle acquisition components. Since potentiometers are vulnerable components with high friction, it is easy to reduce the control accuracy and durability of the joystick, and this type of components has a certain degree of reaction. Phenomena such as empty travel, large wear, and poor dynamic performance cause instability during use. Therefore, people need a rocker handle with higher accuracy, stability and comfort for controlling video games and remote control of drones.

Contents of the invention

In order to overcome the disadvantages of the existing rocker handles, such as a certain amount of reverse air travel, large wear, and poor dynamic performance, the present invention provides a handle rocker system and method based on sensor mpu6050 signal acquisition, the handle rocker system can obtain more Good dynamic performance and static performance, higher accuracy, smoothness and comfort, so as to obtain a better user experience. Described technical scheme is as follows:

A handle rocker system based on sensor mpu6050 signal acquisition, comprising: a signal acquisition module, a wireless transceiver module, a GPIO button module, a power supply voltage stabilization module and a pressure measurement module, the signal acquisition module is connected to the wireless transceiver module, GPIO The button module, the power supply voltage stabilization module and the pressure measurement module are connected, the signal acquisition module includes a microprocessor K60 and a rocker device, the wireless transceiver module includes an NRF24L01 wireless radio frequency module connected with the microprocessor K60, and the GPIO button The module includes external keys and LED indicator lights, the power supply voltage stabilization module includes a battery and a voltage stabilization chip LM-2596, and the pressure measurement module includes a voltage comparator LM301A.

Further, the rocker device includes a rocker, a rotating ball, a compression spring, chip A and chip B, and the rocker passes through the rotating ball to connect chip A and chip B respectively, and one end of the compression spring is connected to the rotating ball connection, the distance between the chip A and the chip B is 100mm, the chip A and the chip B are sensor mpu6050, and the chip A and the chip B are respectively connected with the microprocessor K60.

Further, the power supply voltage stabilizing module uses a 7.2V voltage battery.

Further, the GPIO button module also includes an LCD display.

The present invention also includes a method for obtaining the rocker position based on the signal collected by the sensor mpu6050, the steps are as follows:

S1. Establish a right-handed Cartesian coordinate system on the rocker device as an absolute coordinate system, use the geometric center of chip B as the origin, x, y and z axes represent a fixed reference coordinate system F _{(x, y, z)} , and use chip A The geometric center of is the origin, and the n, o and a axes represent the motion coordinate system F _{(n, o, a)} ;

S2. Finger moves the rocker, chip B performs data collection, obtains the rotation angle α around the x-axis direction, and rotates the angle β around the y-axis direction; chip A performs data collection, obtains the rotation angle γ around the n-axis direction, and rotates the angle γ around the Rotate the δ angle in the direction of the o axis;

S3. The microprocessor K60 reads the data through the IIC protocol, and uses the extended Kalman filter to fuse the angle data collected by the sensor and compensate the error to obtain the optimal estimated value of the joystick;

S4, use the position vector P in the fixed reference coordinate system to establish a mathematical model as:

In the formula, n, o and a represent the direction vector; p represents the position vector; x, y and z are coordinate axes;

S5. The relative coordinate equation of the vector p _xyz is established by using the optimal estimated value obtained after the joystick compensation:

p _xyz = Rot(y,β)Rot(x,α)Rot(n,(γ-α))Rot(o,(δ-β))p _noa

p _xyz is the coordinate point after the transformation of the geometric center of the joystick;

S6, set up the matrix equation of vector p _xyz :

S7, further process the vector to get:

S8. Obtain the coordinates in the plane xy:

The abscissa is:

p _x ＝180(sin(δ-β)cosβ-sin(γ-α)cos(δ-β)sinβsinα+cos(γ-α)sin(δ-β)sinβcosα)

The vertical coordinate is:

p _y =-180(sin(γ-α)cos(δ-β)cosα+cos(γ-α)sin(δ-β)sinα);

Further, in S2, the system state equation and observation equation are established through the extended Kalman filter, as follows:

X _K+1 ＝f(X _K )+w _K+1

Y _K ＝h(X _K )+v _K

In the formula, X _K+1 is the state variable of the system at time k+1, Y _K is the measured variable of the system at time k, and w and v are zero-mean Gaussian white noise.

Through the nonlinear function Taylor series expansion linearization method, the state equation and observation equation of the initial system can be approximated, as follows:

In the formula, F _X (K) and F _w are partial derivatives to X and v respectively; H _X (K) and H _v are partial derivatives to X and w respectively.

State estimation before prediction ^[ :

Variance estimates before forecasting:

where Q(K) is the process excitation noise covariance matrix at time K. After the system is adjusted and corrected in real time, the state update equation is obtained. Its gain matrix, state estimate and variance estimate are:

The beneficial effects of the present invention are:

The handle and rocker system and method based on the signal collected by the sensor mpu6050 of the present invention can obtain better dynamic performance and static performance, higher accuracy, stability and comfort, thereby obtaining better user experience.

Description of drawings

Fig. 1 is a block diagram of the system structure of the present invention;

Fig. 2 is a structural diagram of the rocker device of the present invention;

Fig. 3 is the data transmission interface figure of microprocessor K60 of the present invention and sensor mpu6050;

Fig. 4 is the communication interface figure of microprocessor K60 of the present invention and wireless radio frequency module NRF24L01;

Fig. 5 is a circuit diagram of the power supply voltage stabilizing module LM2596 and the voltage measuring module LM301A of the present invention.

Detailed ways

Example 1:

A handle rocker system based on sensor mpu6050 signal acquisition, comprising: a signal acquisition module, a wireless transceiver module, a GPIO button module, a power supply voltage stabilization module and a pressure measurement module, the signal acquisition module is connected to the wireless transceiver module, GPIO The button module, the power supply voltage stabilization module and the pressure measurement module are connected.

The signal acquisition module includes a microprocessor K60 and a rocker device, and the K60 is a microprocessor MK60N512VLQ100.

The wireless transceiver module includes an NRF24L01 wireless radio frequency module connected to the microprocessor K60. The NRF24L01 wireless radio frequency module is a new type of single-chip radio frequency transceiver device, which works in the 2.4-2.5GH ISM frequency band, has a built-in frequency synthesizer, and incorporates an enhanced ShockBurst technology. Its output power and communication channel are configured through the program. Direct mode can add password and transmission address on the transmitter through software. It has the characteristics of low power consumption, strong anti-interference ability during transmission, and accurate transmission data, which meets the requirements for data transmission of handles and joysticks. As shown in Figure 4, RF_SCK is a transmission clock signal used to control the timing and rate of data exchange. RF_MOSI and RF_MOSO are data input and output relative to the master device, and mainly transmit and exchange data according to the clock signal.

The GPIO button module includes external buttons and LED indicators, and the GPIO button module also includes an LCD display.

The power supply voltage stabilizing module includes a battery and a voltage stabilizing chip LM-2596, and the voltage measuring module includes a voltage comparator LM301A.

The rocker device includes a rocker, a rotating ball, a compression spring, a chip A and a chip B, and the rocker passes through the rotating ball to connect the chip A and the chip B respectively, and one end of the compression spring is connected to the rotating ball, so The distance between the chip A and the chip B is 100 mm, the chip A and the chip B are sensor mpu6050, and the chip A and the chip B are respectively connected with the microprocessor K60. Due to the advantages of the non-contact friction of the compression spring of the elastic element, the device avoids the friction during the movement of the rocker, improves the control accuracy and durability, and realizes unlimited high-precision use. At the same time, the strength and comfort of the rocker when it is operated have been greatly improved.

The rocker produces angular displacement when swinging, and the rotating ball will deform the variable-pitch spring, and the rocker will generate a moment opposite to the direction of motion, which also meets the accuracy requirements when the rocker returns to the neutral position. The sensor chips A and B will also have corresponding angular displacement changes, and the position of the rocker movement can be obtained by the following method.

A method for obtaining the position of the joystick based on the signal collected by the sensor mpu6050, the steps are as follows:

S1. Establish a right-handed Cartesian coordinate system on the rocker device as an absolute coordinate system, use the geometric center of chip B as the origin, x, y and z axes represent a fixed reference coordinate system F _{(x, y, z)} , and use chip A The geometric center of is the origin, and the n, o and a axes represent the motion coordinate system F _{(n, o, a)} ;

S2. Finger moves the rocker, chip B performs data collection, obtains the rotation angle α around the x-axis direction, and rotates the angle β around the y-axis direction; chip A performs data collection, obtains the rotation angle γ around the n-axis direction, and rotates the angle γ around the Rotate the δ angle in the direction of the o axis;

S3. The microprocessor K60 reads the data through the IIC protocol, and uses the extended Kalman filter to fuse the angle data collected by the sensor and compensate the error to obtain the optimal estimated value of the joystick;

S4, use the position vector P in the fixed reference coordinate system to establish a mathematical model as:

In the formula, n, o and a represent the direction vector; p represents the position vector; x, y and z are coordinate axes;

S5. The relative coordinate equation of the vector p _xyz is established by using the optimal estimated value obtained after the joystick compensation:

p _xyz = Rot(y,β)Rot(x,α)Rot(n,(γ-α))Rot(o,(δ-β))p _noa

p _xyz is the coordinate point after the transformation of the geometric center of the joystick;

S6, set up the matrix equation of vector p _xyz :

S7, further process the vector to get:

S8. Obtain the coordinates in the plane xy:

The abscissa is:

p _x ＝180(sin(δ-β)cosβ-sin(γ-α)cos(δ-β)sinβsinα+cos(γ-α)sin(δ-β)sin

The vertical coordinate is:

p _y =-180(sin(γ-α)cos(δ-β)cosα+cos(γ-α)sin(δ-β)sinα);

In S2, the system state equation and observation equation are established by extended Kalman filter, as follows:

X _K+1 ＝f(X _K )+w _K+1

Y _K ＝h(X _K )+v _K

In the formula, X _K+1 is the state variable of the system at time k+1, Y _K is the measured variable of the system at time k, and w and v are zero-mean Gaussian white noise.

Through the nonlinear function Taylor series expansion linearization method, the state equation and observation equation of the initial system can be approximated, as follows:

In the formula, F _X (K) and F _w are partial derivatives to X and v respectively; H _X (K) and H _v are partial derivatives to X and w respectively.

State estimation before prediction ^[ :

Variance estimates before forecasting:

where Q(K) is the process excitation noise covariance matrix at time K. After the system is adjusted and corrected in real time, the state update equation is obtained. Its gain matrix, state estimate and variance estimate are:

Example 2:

As a supplement to the joystick and rocker system based on the sensor mpu6050 collecting signals in the first embodiment, the whole system uses a 7.2V battery voltage, and the battery voltage is regulated to 3.3V by the voltage stabilizing module. Because the modules of the entire system are only powered by 3.3V voltage, the voltage regulator module only needs to perform one-stage step-down and voltage regulation. Chip, current has very good linearity and load regulation characteristics. Small power, high efficiency, the stable working current of the whole system can reach 0.8A, and the instantaneous working current is about 1.2A. Therefore, the power supply design of this application meets the requirements of the system work. Since the mpu6050 sensor chip requires extremely high operating voltage, a voltage measurement module is added to this design system, and the battery power is read out through the voltage comparator LM301A to ensure that the system always works stably within the effective voltage range.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (2)

1. a kind of method for obtaining rocking bar position based on sensor mpu6050 acquisition signal, which is characterized in that steps are as follows:

S1, right-handed Cartesian coordinate system is established on rocker actuator as absolute coordinate system, the geometric center with chip B is origin, X, y and z axes indicate fixed reference frame F_{(x, y, z)}, the geometric center with chip A is origin, and n, o and a axis indicate the coordinates of motion It is F_{(n, o, a)}；

S2, finger stir rocking bar, and chip B carries out data acquisition, obtain the rotation alpha angle in x-axis direction, revolve on y-axis direction Turn β angle；Chip A carries out data acquisition, obtains and rotates γ angle in n axis direction, and δ angle is rotated in o axis direction；

S3, microprocessor K60 read data by IIC agreement, and use Extended Kalman filter by the angle of sensor collection Data merge and compensate to error, obtain the optimal estimation value of handle rocker；

S4, position vector P founding mathematical models are used in fixed reference frame are as follows:

In formula, n, o and a indicate direction vector；P indicates position vector；X, y and z is reference axis；

S5, the optimal estimation value obtained after being compensated using handle rocker establish vector p_xyzRelative coordinate equation are as follows:

p_xyz=Rot (y, β) Rot (x, α) Rot (n, (γ-α)) Rot (o, (δ-β)) p_noa

p_xyzFor the transformed coordinate points of handle rocker geometric center；

S6, vector p is established_xyzMatrix equation:

S7, it is further processed to measuring:

S8, the coordinate obtained in plane xy:

Abscissa are as follows:

p_x=180 (sin (δ-β) cos β-sin (γ-α) cos (δ-β) sin β sin α+cos (γ-α) sin (δ-β) sin β cos α)

Ordinate are as follows:

p_y=-180 (sin (γ-α) cos (δ-β) cos α+cos (γ-α) sin (δ-β) sin α).

2. the method for obtaining rocking bar position based on sensor mpu6050 acquisition signal as described in claim 1, feature exist In, in S2, system state equation and observational equation are established by Extended Kalman filter, as follows:

X_K+1=f (X_K)+w_K+1

Y_K=h (X_K)+v_K

In formula, X_K+1State variable for system at the k+1 moment, Y_KMeasurand for system at the k moment, w, v are that zero-mean is high This white noise.

By nonlinear function Taylor series expansion linearization technique, state equation and the sight of initial system can be approximately indicated Equation is surveyed, as follows:

In formula, F_X(K) and F_wIt is the partial derivative to X, v respectively；H_X(K) and H_vIt is the partial derivative to X, w respectively.

State estimation before prediction^[:

Variance evaluation before prediction:

In formula, Q (K) is the procedure activation noise covariance matrix at K moment.After system is by adjustment amendment in real time,

Must do well renewal equation.Its gain matrix, state estimation and variance evaluation are respectively as follows: