用 Tank Drive 和 Joystick 操控机器人
一个常见的用例是有一个操纵杆来驱动作为子系统一部分的一些执行器。问题是操纵杆是在 RobotContainer 类中创建的，要控制的电机在子系统中。这个想法是创建一个指令，在调度时从操纵杆读取输入并调用在驱动电机的子系统上创建的方法。
在这个例子中，一个底盘子系统在一个用一对操纵杆的 tank drive 被运行。
建造一个 Drive Train Subsystem 。
创建一个名为 Drive Train 的子系统。它的职责是处理机器人基地的驱动。
Inside the Drive Train, create a Differential Drive object. The Differential Drive object can contain a left motor controller and a right motor controller.
Create two Motor Controllers in the Differential Drive, and two more outside the Differential Drive, inside the Drive Train subsystem.
In the Differential Drive, set the left and right motors to the appropriate motor controllers.
Finally, for the two motor controllers that aren’t in the differential drive, set them to follow the motor controllers in the differential drive.
将 Joystick 添加到 Operator Interface。
将两个操纵杆添加到 Operator Interface。其中一个为左杆，另一个为右杆。两个操纵杆的y轴是用来让机器人左右移动的。
备注
注意在继续下一步前用 C++ 或 Java 输出程序。
建造一个 Method 来在 Subsystem 中 Write the Motor。
11// ROBOTBUILDER TYPE: Subsystem.
12
13package frc.robot.subsystems;
14
15
16import frc.robot.commands.*;
17import edu.wpi.first.wpilibj.livewindow.LiveWindow;
18import edu.wpi.first.wpilibj2.command.SubsystemBase;
19
20// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=IMPORTS
21import edu.wpi.first.wpilibj.AnalogGyro;
22import edu.wpi.first.wpilibj.AnalogInput;
23import edu.wpi.first.wpilibj.CounterBase.EncodingType;
24import edu.wpi.first.wpilibj.Encoder;
25import edu.wpi.first.wpilibj.drive.DifferentialDrive;
26import edu.wpi.first.wpilibj.motorcontrol.PWMVictorSPX;
27
28 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=IMPORTS
29
30
31/**
32 *
33 */
34public class DriveTrain extends SubsystemBase {
35 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTANTS
36public static final double PlaceDistance = 0.1;
37public static final double BackAwayDistance = 0.6;
38
39 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTANTS
40
41 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
42private PWMVictorSPX left1;
43private PWMVictorSPX right1;
44private DifferentialDrive drive;
45private PWMVictorSPX left2;
46private PWMVictorSPX right2;
47private Encoder leftencoder;
48private Encoder rightencoder;
49private AnalogGyro gyro;
50private AnalogInput rangefinder;
51
52 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
53
54 /**
55 *
56 */
57 public DriveTrain() {
58 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTORS
59left1 = new PWMVictorSPX(0);
60 addChild("left1",left1);
61 left1.setInverted(false);
62
63right1 = new PWMVictorSPX(1);
64 addChild("right1",right1);
65 right1.setInverted(true);
66
67drive = new DifferentialDrive(left1, right1);
68 addChild("Drive",drive);
69 drive.setSafetyEnabled(true);
70drive.setExpiration(0.1);
71drive.setMaxOutput(1.0);
72
73
74left2 = new PWMVictorSPX(2);
75 addChild("left2",left2);
76 left1.addFollower(left2);
77left2.setInverted(false);
78
79right2 = new PWMVictorSPX(3);
80 addChild("right2",right2);
81 right1.addFollower(right2);
82right2.setInverted(false);
83
84leftencoder = new Encoder(0, 1, false, EncodingType.k4X);
85 addChild("left encoder",leftencoder);
86 leftencoder.setDistancePerPulse(1.0);
87
88rightencoder = new Encoder(2, 3, false, EncodingType.k4X);
89 addChild("right encoder",rightencoder);
90 rightencoder.setDistancePerPulse(1.0);
91
92gyro = new AnalogGyro(0);
93 addChild("gyro",gyro);
94 gyro.setSensitivity(0.007);
95
96rangefinder = new AnalogInput(1);
97 addChild("range finder", rangefinder);
98
99
100
101 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTORS
102 }
103
104 @Override
105 public void periodic() {
106 // This method will be called once per scheduler run
107
108 }
109
110 @Override
111 public void simulationPeriodic() {
112 // This method will be called once per scheduler run when in simulation
113
114 }
115
116 // Put methods for controlling this subsystem
117 // here. Call these from Commands.
118
119 public void drive(double left, double right) {
120 drive.tankDrive(left, right);
121 }
122
123 public void stop() {
124 drive.tankDrive(0.0, 0.0);
125 }
126
127}
11// ROBOTBUILDER TYPE: Subsystem.
12#pragma once
13
14// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES
15#include <frc2/command/SubsystemBase.h>
16#include <frc/AnalogGyro.h>
17#include <frc/AnalogInput.h>
18#include <frc/Encoder.h>
19#include <frc/drive/DifferentialDrive.h>
20#include <frc/motorcontrol/PWMVictorSPX.h>
21
22 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES
23
24/**
25 *
26 *
27 * @author ExampleAuthor
28 */
29class DriveTrain: public frc2::SubsystemBase {
30private:
31 // It's desirable that everything possible is private except
32 // for methods that implement subsystem capabilities
33 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
34frc::AnalogInput m_rangefinder{1};
35frc::AnalogGyro m_gyro{0};
36frc::Encoder m_rightencoder{2, 3, false, frc::Encoder::k4X};
37frc::Encoder m_leftencoder{0, 1, false, frc::Encoder::k4X};
38frc::PWMVictorSPX m_right2{3};
39frc::PWMVictorSPX m_left2{2};
40frc::DifferentialDrive m_drive{m_left1, m_right1};
41frc::PWMVictorSPX m_right1{1};
42frc::PWMVictorSPX m_left1{0};
43
44 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
45public:
46DriveTrain();
47
48 void Periodic() override;
49 void SimulationPeriodic() override;
50 void Drive(double left, double right);
51 void Stop();
52 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CMDPIDGETTERS
53
54 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CMDPIDGETTERS
55 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTANTS
56static constexpr const double PlaceDistance = 0.1;
57static constexpr const double BackAwayDistance = 0.6;
58
59 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTANTS
60
61
62};
11// ROBOTBUILDER TYPE: Subsystem.
12
13// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES
14#include "subsystems/DriveTrain.h"
15#include <frc/smartdashboard/SmartDashboard.h>
16
17 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES
18
19DriveTrain::DriveTrain(){
20 SetName("Drive Train");
21 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
22 SetSubsystem("Drive Train");
23
24 AddChild("range finder", &m_rangefinder);
25
26
27 AddChild("gyro", &m_gyro);
28 m_gyro.SetSensitivity(0.007);
29
30 AddChild("right encoder", &m_rightencoder);
31 m_rightencoder.SetDistancePerPulse(1.0);
32
33 AddChild("left encoder", &m_leftencoder);
34 m_leftencoder.SetDistancePerPulse(1.0);
35
36 AddChild("right2", &m_right2);
37 m_right2.SetInverted(false);
38m_right1.AddFollower(m_right2);
39
40 AddChild("left2", &m_left2);
41 m_left2.SetInverted(false);
42m_left1.AddFollower(m_left2);
43
44 AddChild("Drive", &m_drive);
45 m_drive.SetSafetyEnabled(true);
46m_drive.SetExpiration(0.1_s);
47m_drive.SetMaxOutput(1.0);
48
49
50 AddChild("right1", &m_right1);
51 m_right1.SetInverted(true);
52
53
54 AddChild("left1", &m_left1);
55 m_left1.SetInverted(false);
56
57
58 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
59}
60
61void DriveTrain::Periodic() {
62 // Put code here to be run every loop
63
64}
65
66void DriveTrain::SimulationPeriodic() {
67 // This method will be called once per scheduler run when in simulation
68
69}
70
71// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CMDPIDGETTERS
72
73 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CMDPIDGETTERS
74
75
76// Put methods for controlling this subsystem
77// here. Call these from Commands.
78
79void DriveTrain::Drive(double left, double right) {
80 m_drive.TankDrive(left, right);
81}
82
83void DriveTrain::Stop() {
84 m_drive.TankDrive(0.0, 0.0);
85}
Create a method that takes the joystick inputs, in this case the left and right driver joystick. The values are passed to the DifferentialDrive object that in turn does tank steering using the joystick values. Also create a method called stop() that stops the robot from driving, this might come in handy later.
读取 Joystick Values 和 Call the Subsystem Methods 。
创建一个指令，在本例中称为 Tank Drive。它的目的是读取操纵杆值并将它们发送到 Drive Base 子系统。请注意，此指令需要 Drive Train 子系统。这将导致它在任何其他尝试使用 Drive Train 时停止运行。
Create two parameters (DoubleSupplier for Java or std::function<double()> for C++) for the left and right speeds.
Create a parameter preset to retrieve joystick values. Java: For the left parameter enter () -> getJoystick1().getY() and for right enter () -> getJoystick2().getY(). C++: For the left parameter enter [this] {return getJoystick1()->GetY();} and for the right enter [this] {return getJoystick2()->GetY();}
备注
注意在继续下一步前用 C++ 或 Java 输出程序。
把这个代码加入到 Driving 中。
11// ROBOTBUILDER TYPE: Command.
12
13package frc.robot.commands;
14import edu.wpi.first.wpilibj2.command.Command;
15import java.util.function.DoubleSupplier;
16
17// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=IMPORTS
18import frc.robot.subsystems.DriveTrain;
19
20 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=IMPORTS
21
22/**
23 *
24 */
25public class TankDrive extends Command {
26
27 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=VARIABLE_DECLARATIONS
28 private final DriveTrain m_driveTrain;
29 private DoubleSupplier m_left;
30 private DoubleSupplier m_right;
31
32 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=VARIABLE_DECLARATIONS
33
34 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTORS
35
36
37 public TankDrive(DoubleSupplier left, DoubleSupplier right, DriveTrain subsystem) {
38
39 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTORS
40 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=VARIABLE_SETTING
41 m_left = left;
42 m_right = right;
43
44 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=VARIABLE_SETTING
45 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=REQUIRES
46
47 m_driveTrain = subsystem;
48 addRequirements(m_driveTrain);
49
50 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=REQUIRES
51 }
52
53 // Called when the command is initially scheduled.
54 @Override
55 public void initialize() {
56 }
57
58 // Called every time the scheduler runs while the command is scheduled.
59 @Override
60 public void execute() {
61 m_driveTrain.drive(m_left.getAsDouble(), m_right.getAsDouble());
62 }
63
64 // Called once the command ends or is interrupted.
65 @Override
66 public void end(boolean interrupted) {
67 m_driveTrain.stop();
68 }
69
70 // Returns true when the command should end.
71 @Override
72 public boolean isFinished() {
73 return false;
74 }
75
76 @Override
77 public boolean runsWhenDisabled() {
78 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DISABLED
79 return false;
80
81 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DISABLED
82 }
83}
11// ROBOTBUILDER TYPE: Command.
12
13#pragma once
14
15 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES
16
17#include <frc2/command/CommandHelper.h>
18#include <frc2/command/Command.h>
19
20#include "subsystems/DriveTrain.h"
21
22 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=INCLUDES
23
24/**
25 *
26 *
27 * @author ExampleAuthor
28 */
29class TankDrive: public frc2::CommandHelper<frc2::Command, TankDrive> {
30public:
31 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTOR
32 explicit TankDrive(std::function<double()> left, std::function<double()> right, DriveTrain* m_drivetrain);
33
34 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTOR
35
36void Initialize() override;
37void Execute() override;
38bool IsFinished() override;
39void End(bool interrupted) override;
40bool RunsWhenDisabled() const override;
41
42
43private:
44 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=VARIABLES
45
46std::function<double()> m_left;
47std::function<double()> m_right;
48
49DriveTrain* m_drivetrain;
50
51
52 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=VARIABLES
53};
11// ROBOTBUILDER TYPE: Command.
12
13// BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTOR
14
15#include "commands/TankDrive.h"
16
17TankDrive::TankDrive(std::function<double()> left, std::function<double()> right, DriveTrain* m_drivetrain) :
18 m_left(left),
19 m_right(right),
20m_drivetrain(m_drivetrain)
21{
22
23 // Use AddRequirements() here to declare subsystem dependencies
24 // eg. AddRequirements(m_Subsystem);
25 SetName("TankDrive");
26 AddRequirements({m_drivetrain});
27
28 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTOR
29
30}
31
32// Called just before this Command runs the first time
33void TankDrive::Initialize() {
34
35}
36
37// Called repeatedly when this Command is scheduled to run
38void TankDrive::Execute() {
39 m_drivetrain->Drive(m_left(),m_right());
40}
41
42// Make this return true when this Command no longer needs to run execute()
43bool TankDrive::IsFinished() {
44 return false;
45}
46
47// Called once after isFinished returns true
48void TankDrive::End(bool interrupted) {
49 m_drivetrain->Drive(0,0);
50}
51
52bool TankDrive::RunsWhenDisabled() const {
53 // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DISABLED
54 return false;
55
56 // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DISABLED
57}
Add code to the execute method to do the actual driving. All that is needed is pass the for the left and right parameters to the Drive Train subsystem. The subsystem just uses them for the tank steering method on its DifferentialDrive object. And we get tank steering.
我们还填写了 end() 方法，以便当此指令被中断或停止时，电机将停止作为安全预防措施。
创建 Default Command 。
最后一步是使 Tank Drive 指令成为 Drive Train 子系统的“默认指令”。这意味着只要没有其他指令使用 Drive Train，操纵杆将处于控制之中。这可能是理想的行为。当自动阶段代码运行时，它还需要传动系统并中断 Tank Drive 指令。自动阶段代码完成后，DriveWithJoysticks 指令将自动重新启动（因为它是默认命令），操作员将重新获得控制权。如果您编写任何执行遥控自动驾驶的代码，这些指令也应该“需要”DriveTrain，以便它们也会中断 Tank Drive 指令并拥有完全控制权。
The final step is to choose the joystick parameter preset previously set up.
备注
确保在继续前把你的程序导出到 C++ 或 Java。