4-channel tracking

The tutorial mainly demonstrates the patrol function of the balance car combined with the four-way tracking module.

The tutorial only introduces the standard library project code

Hardware connection

Control principle

By reading the X1, X2, X3, and X4 interface levels of the four-way tracking module, it is determined whether the black line is detected and where the black line is located.

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The program uses PID to implement the line patrol function. If the PID parameters are not used, the effect is poor.

Black line detected

The light is on → The corresponding interface of the four-way line patrol module outputs a low level;

White line detected

The light is off → The corresponding interface of the four-way line patrol module outputs a high level.

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Note: The corresponding relationship between the interface, LED, and adjustment knob shall be based on the silkscreen numbers, for example: X1 corresponds to L1, SW1

Main code

The tutorial mainly explains the code for the four-way patrol function. For detailed code, refer to the corresponding project file.

Turn_IRTrack_PD

Four-way patrol module patrol PID implementation function. If the patrol effect is not good, modify the PID parameters of the app_tracking.c file. It is not recommended to modify the PID parameters of the pid_control.c file (the PID parameters of the pid_control.c file are subject to the parameters finally confirmed in the balance car parameter adjustment tutorial).

​x
int Turn_IRTrack_PD(float gyro)
{
    int IRTrackTurn = 0;
    float err = 0;  
    static float IRTrack_Integral;

    PID_track_get();  // Obtain deviation

    err=error-IRTrack_Minddle;

    IRTrack_Integral +=err;

    IRTrackTurn=err*IRTrack_Trun_KP+IRTrack_Trun_KI*IRTrack_Integral+gyro*IRTrack_Trun_KD;

    return IRTrackTurn;
}

Program flow chart

Briefly introduce the process of function implementation:

Experimental phenomenon

Software code

The BalancedCar_tracking_PID.hex file generated by the project compilation is located in the OBJ folder of the BalancedCar_tracking_PID project. Find the BalancedCar_tracking_PID.hex file corresponding to the project and use the FlyMcu software to download the program into the development board.

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Product supporting data source code path: Attachment → Source code summary → 5.Balanced_Car_Extended → 01.BalancedCar_tracking_PID

Experimental phenomenon

After the program is started, put the car on the patrol map, and press KEY1 according to the OLED prompt to start the balance car patrol function: OLED will display the deviation setting value and the level of the four-way patrol module in real time!

The balance car will balance first and then patrol the line. When the inclination angle is greater than a certain value, the car will stop moving.

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The program has voltage detection. If the voltage is less than 9.6V, the low voltage alarm will be triggered and the buzzer will sound.
Common situations for triggering voltage alarms:
1. The power switch of the development board is not turned on, and only the Type-C data cable is connected for power supply
2. The battery pack voltage is lower than 9.6V and needs to be charged in time

Extended case: Four-way patrol (high-difficulty map)

This case is used with our smart car patrol track. It is difficult for novices to adjust, so only code reference is provided.

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Product supporting information source code path: Attachment → Source code summary → 5.Balanced_Car_Extended → 01.BalancedCar_tracking_PID → BalancedCar_tracking_yahboom_map