Closed-Loop Control#
Phoenix 6 enhances the experience of using onboard closed-loop control through the use of standardized units and a variety of control output types.
Note
For more information about closed-loop control in Phoenix 6, see Closed-Loop Overview.
Closed-Loop Setpoints#
Phoenix 6 uses canonical units for closed-loop setpoints.
| Setpoint Conversion | ||||
|---|---|---|---|---|
| Name | Value | Units | Formula | |
| Position | Original | \(\mathrm{raw\_units}\) | \(x_{\mathrm{old}}\) | |
| New | \(\mathrm{rotations}\) | \(x_{\mathrm{new}}=x_{\mathrm{old}} \cdot \frac{1}{2048} \frac{\mathrm{rot}}{\mathrm{raw\_unit}}\) | ||
| Velocity | Original | \(\frac{\mathrm{raw\_units}}{\mathrm{100ms}}\) | \(v_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{rot}}{\mathrm{second}}\) | \(v_{\mathrm{new}}=v_{\mathrm{old}} \cdot \frac{1}{2048} \frac{\mathrm{rot}}{\mathrm{raw\_unit}} \cdot 10 \frac{\mathrm{100ms}}{\mathrm{second}} \) | ||
| Acceleration | Original | \(\frac{\mathrm{raw\_units}}{\mathrm{100ms} \cdot \mathrm{second}}\) | \(a_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{rot}}{\mathrm{second}^2}\) | \(a_{\mathrm{new}}=a_{\mathrm{old}} \cdot \frac{1}{2048} \frac{\mathrm{rot}}{\mathrm{raw\_unit}} \cdot 10 \frac{\mathrm{100ms}}{\mathrm{second}} \) | ||
Closed-Loop Gains#
Position without Voltage Comp#
Phoenix 5 ControlMode.Position with voltage compensation disabled maps to the Phoenix 6 PositionDutyCycle control request.
| Position without Voltage Compensation | ||||
|---|---|---|---|---|
| Name | Value | Units | Formula | |
| kP | Original | \(\frac{\mathrm{raw\_output}}{\mathrm{unit}}\) | \(kP_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{duty\_cycle}}{\mathrm{rot}}\) | \(kP_{\mathrm{new}}=kP_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}}\) | ||
| kI | Original | \(\frac{\mathrm{raw\_output}}{\mathrm{unit} \cdot \mathrm{millisecond}}\) | \(kI_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{duty\_cycle}}{\mathrm{rot} \cdot \mathrm{second}}\) | \(kI_{\mathrm{new}}=kI_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot 1000 \frac{\mathrm{millisecond}}{\mathrm{second}}\) | ||
| kD | Original | \(\frac{\mathrm{raw\_output}}{\mathrm{unit} / \mathrm{millisecond}}\) | \(kD_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{duty\_cycle}}{\mathrm{rot} / \mathrm{second}}\) | \(kD_{\mathrm{new}}=kD_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot \frac{1}{1000} \frac{\mathrm{second}}{\mathrm{millisecond}}\) | ||
Position with Voltage Comp#
Phoenix 5 ControlMode.Position with voltage compensation enabled has been replaced with the Phoenix 6 PositionVoltage control request, which directly controls voltage.
| Position with Voltage Compensation | ||||
|---|---|---|---|---|
| Name | Value | Units | Formula | |
| kP | Original | \(\frac{\mathrm{\mathrm{raw\_output}}}{\mathrm{unit}}\) | \(kP_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{V}}{\mathrm{rot}}\) | \(kP_{\mathrm{new}}=kP_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot \mathrm{V\_comp} \frac{\mathrm{V}}{\mathrm{duty\_cycle}}\) | ||
| kI | Original | \(\frac{\mathrm{\mathrm{raw\_output}}}{\mathrm{unit} \cdot \mathrm{millisecond}}\) | \(kI_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{V}}{\mathrm{rot} \cdot \mathrm{second}}\) | \(kI_{\mathrm{new}}=kI_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot 1000 \frac{\mathrm{millisecond}}{\mathrm{second}} \cdot \mathrm{V\_comp} \frac{\mathrm{V}}{\mathrm{duty\_cycle}}\) | ||
| kD | Original | \(\frac{\mathrm{\mathrm{raw\_output}}}{\mathrm{unit} / \mathrm{millisecond}}\) | \(kD_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{V}}{\mathrm{rot} / \mathrm{second}}\) | \(kD_{\mathrm{new}}=kD_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot \frac{1}{1000} \frac{\mathrm{second}}{\mathrm{millisecond}} \cdot \mathrm{V\_comp} \frac{\mathrm{V}}{\mathrm{duty\_cycle}}\) | ||
Velocity without Voltage Comp#
Phoenix 5 ControlMode.Velocity with voltage compensation disabled maps to the Phoenix 6 VelocityDutyCycle control request.
Additionally, kF from Phoenix 5 has been replaced with kV in Phoenix 6.
| Velocity without Voltage Compensation | ||||
|---|---|---|---|---|
| Name | Value | Units | Formula | |
| kP | Original | \(\frac{\mathrm{raw\_output}}{\mathrm{unit} / \mathrm{100ms}}\) | \(kP_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{duty\_cycle}}{\mathrm{rot} / \mathrm{sec}}\) | \(kP_{\mathrm{new}}=kP_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot \frac{1}{10} \frac{\mathrm{sec}}{\mathrm{100ms}}\) | ||
| kI | Original | \(\frac{\mathrm{raw\_output}}{(\mathrm{unit} / \mathrm{100ms}) \cdot \mathrm{millisecond}}\) | \(kI_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{duty\_cycle}}{\mathrm{rot}}\) | \(kI_{\mathrm{new}}=kI_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot 1000 \frac{\mathrm{millisecond}}{\mathrm{second}} \cdot \frac{1}{10} \frac{\mathrm{sec}}{\mathrm{100ms}}\) | ||
| kD | Original | \(\frac{\mathrm{raw\_output}}{(\mathrm{unit} / \mathrm{100ms}) / \mathrm{millisecond}}\) | \(kD_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{duty\_cycle}}{\mathrm{rot} / \mathrm{second}^{2}}\) | \(kD_{\mathrm{new}}=kD_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot \frac{1}{1000} \frac{\mathrm{second}}{\mathrm{millisecond}} \cdot \frac{1}{10} \frac{\mathrm{sec}}{\mathrm{100ms}}\) | ||
| kF kV |
Original | \(\frac{\mathrm{raw\_output}}{\mathrm{unit} / \mathrm{100millisecond}}\) | \(kF_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{duty\_cycle}}{\mathrm{rot} / \mathrm{second}}\) | \(kV_{\mathrm{new}}=kF_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot \frac{1}{10} \frac{\mathrm{second}}{\mathrm{100ms}}\) | ||
Velocity with Voltage Comp#
Phoenix 5 ControlMode.Velocity with voltage compensation enabled has been replaced with the Phoenix 6 VelocityVoltage control request, which directly controls voltage.
Additionally, kF from Phoenix 5 has been replaced with kV in Phoenix 6.
| Velocity with Voltage Compensation | ||||
|---|---|---|---|---|
| Name | Value | Units | Formula | |
| kP | Original | \(\frac{\mathrm{\mathrm{raw\_output}}}{\mathrm{unit} / \mathrm{100ms}}\) | \(kP_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{V}}{\mathrm{rot} / \mathrm{sec}}\) | \(kP_{\mathrm{new}}=kP_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot \frac{1}{10} \frac{\mathrm{second}}{\mathrm{100ms}} \cdot \mathrm{V\_comp} \frac{\mathrm{V}}{\mathrm{duty\_cycle}}\) | ||
| kI | Original | \(\frac{\mathrm{\mathrm{raw\_output}}}{(\mathrm{unit} / \mathrm{100ms}) \cdot \mathrm{millisecond}}\) | \(kI_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{V}}{\mathrm{rot}}\) | \(kI_{\mathrm{new}}=kI_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot 1000 \frac{\mathrm{millisecond}}{\mathrm{second}} \cdot \frac{1}{10} \frac{\mathrm{second}}{\mathrm{100ms}} \cdot \mathrm{V\_comp} \frac{\mathrm{V}}{\mathrm{duty\_cycle}}\) | ||
| kD | Original | \(\frac{\mathrm{\mathrm{raw\_output}}}{(\mathrm{unit} / \mathrm{100ms}) / \mathrm{millisecond}}\) | \(kD_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{V}}{\mathrm{rot} / \mathrm{second}^{2}}\) | \(kD_{\mathrm{new}}=kD_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot \frac{1}{1000} \frac{\mathrm{second}}{\mathrm{millisecond}} \cdot \frac{1}{10} \frac{\mathrm{second}}{\mathrm{100ms}} \cdot \mathrm{V\_comp} \frac{\mathrm{V}}{\mathrm{duty\_cycle}}\) | ||
| kF kV |
Original | \(\frac{\mathrm{\mathrm{raw\_output}}}{\mathrm{unit} / \mathrm{100ms}}\) | \(kF_{\mathrm{old}}\) | |
| New | \(\frac{\mathrm{V}}{\mathrm{rot} / \mathrm{second}}\) | \(kV_{\mathrm{new}}=kF_{\mathrm{old}} \cdot 2048 \frac{\mathrm{unit}}{\mathrm{rot}} \cdot \frac{1}{1023} \frac{\mathrm{duty\_cycle}}{\mathrm{raw\_output}} \cdot \frac{1}{10} \frac{\mathrm{second}}{\mathrm{100ms}} \cdot \mathrm{V\_comp} \frac{\mathrm{V}}{\mathrm{duty\_cycle}}\) | ||
Using Closed-Loop Control#
v5 |
// robot init, set slot 0 gains
m_motor.config_kF(0, 0.05, 50);
m_motor.config_kP(0, 0.046, 50);
m_motor.config_kI(0, 0.0002, 50);
m_motor.config_kD(0, 4.2, 50);
// enable voltage compensation
m_motor.configVoltageComSaturation(12);
m_motor.enableVoltageCompensation(true);
// periodic, run velocity control with slot 0 configs,
// target velocity of 50 rps (10240 ticks/100ms)
m_motor.selectProfileSlot(0, 0);
m_motor.set(ControlMode.Velocity, 10240);
// robot init, set slot 0 gains
m_motor.Config_kF(0, 0.05, 50);
m_motor.Config_kP(0, 0.046, 50);
m_motor.Config_kI(0, 0.0002, 50);
m_motor.Config_kD(0, 4.2, 50);
// enable voltage compensation
m_motor.ConfigVoltageComSaturation(12);
m_motor.EnableVoltageCompensation(true);
// periodic, run velocity control with slot 0 configs,
// target velocity of 50 rps (10240 ticks/100ms)
m_motor.SelectProfileSlot(0, 0);
m_motor.Set(ControlMode::Velocity, 10240);
|
v6 |
// class member variable
final VelocityVoltage m_velocity = new VelocityVoltage(0);
// robot init, set slot 0 gains
var slot0Configs = new Slot0Configs();
slot0Configs.kV = 0.12;
slot0Configs.kP = 0.11;
slot0Configs.kI = 0.48;
slot0Configs.kD = 0.01;
m_talonFX.getConfigurator().apply(slot0Configs, 0.050);
// periodic, run velocity control with slot 0 configs,
// target velocity of 50 rps
m_velocity.Slot = 0;
m_motor.setControl(m_velocity.withVelocity(50));
// class member variable
controls::VelocityVoltage m_velocity{0_tps};
// robot init, set slot 0 gains
configs::Slot0Configs slot0Configs{};
slot0Configs.kV = 0.12;
slot0Configs.kP = 0.11;
slot0Configs.kI = 0.48;
slot0Configs.kD = 0.01;
m_talonFX.GetConfigurator().Apply(slot0Configs, 50_ms);
// periodic, run velocity control with slot 0 configs,
// target velocity of 50 rps
m_velocity.Slot = 0;
m_motor.SetControl(m_velocity.WithVelocity(50_tps));
|
Motion Magic®#
v5 |
// robot init, set slot 0 gains
m_motor.config_kF(0, 0.05, 50);
// PID runs on position
m_motor.config_kP(0, 0.2, 50);
m_motor.config_kI(0, 0, 50);
m_motor.config_kD(0, 4.2, 50);
// set Motion Magic settings
m_motor.configMotionCruiseVelocity(16384); // 80 rps = 16384 ticks/100ms cruise velocity
m_motor.configMotionAcceleration(32768); // 160 rps/s = 32768 ticks/100ms/s acceleration
m_motor.configMotionSCurveStrength(3); // s-curve smoothing strength of 3
// enable voltage compensation
m_motor.configVoltageComSaturation(12);
m_motor.enableVoltageCompensation(true);
// periodic, run Motion Magic with slot 0 configs
m_motor.selectProfileSlot(0, 0);
// target position of 200 rotations (409600 ticks)
// add 0.02 (2%) arbitrary feedforward to overcome friction
m_motor.set(ControlMode.MotionMagic, 409600, DemandType.ArbitraryFeedforward, 0.02);
// robot init, set slot 0 gains
m_motor.Config_kF(0, 0.05, 50);
// PID runs on position
m_motor.Config_kP(0, 0.2, 50);
m_motor.Config_kI(0, 0, 50);
m_motor.Config_kD(0, 4.2, 50);
// set Motion Magic settings
m_motor.ConfigMotionCruiseVelocity(16384); // 80 rps = 16384 ticks/100ms cruise velocity
m_motor.ConfigMotionAcceleration(32768); // 160 rps/s = 32768 ticks/100ms/s acceleration
m_motor.ConfigMotionSCurveStrength(3); // s-curve smoothing strength of 3
// enable voltage compensation
m_motor.ConfigVoltageComSaturation(12);
m_motor.EnableVoltageCompensation(true);
// periodic, run Motion Magic with slot 0 configs
m_motor.SelectProfileSlot(0, 0);
// target position of 200 rotations (409600 ticks)
// add 0.02 (2%) arbitrary feedforward to overcome friction
m_motor.Set(ControlMode::MotionMagic, 409600, DemandType::ArbitraryFeedforward, 0.02);
|
v6 |
Note The Motion Magic® S-Curve Strength has been replaced with jerk control in Phoenix 6. // class member variable
final MotionMagicVoltage m_motmag = new MotionMagicVoltage(0);
// robot init
var talonFXConfigs = new TalonFXConfiguration();
// set slot 0 gains
var slot0Configs = talonFXConfigs.Slot0Configs;
slot0Configs.kS = 0.24; // add 0.24 V to overcome friction
slot0Configs.kV = 0.12; // apply 12 V for a target velocity of 100 rps
// PID runs on position
slot0Configs.kP = 4.8;
slot0Configs.kI = 0;
slot0Configs.kD = 0.1;
// set Motion Magic settings
var motionMagicConfigs = talonFXConfigs.MotionMagicConfigs;
motionMagicConfigs.MotionMagicCruiseVelocity = 80; // 80 rps cruise velocity
motionMagicConfigs.MotionMagicAcceleration = 160; // 160 rps/s acceleration (0.5 seconds)
motionMagicConfigs.MotionMagicJerk = 1600; // 1600 rps/s^2 jerk (0.1 seconds)
m_talonFX.getConfigurator().apply(talonFXConfigs, 0.050);
// periodic, run Motion Magic with slot 0 configs,
// target position of 200 rotations
m_motmag.Slot = 0;
m_motor.setControl(m_motmag.withPosition(200));
// class member variable
controls::MotionMagicVoltage m_motmag{0_tr};
// robot init
configs::TalonFXConfiguration talonFXConfigs{};
// set slot 0 gains
auto& slot0Configs = talonFXConfigs.Slot0Configs;
slot0Configs.kS = 0.24; // add 0.24 V to overcome friction
slot0Configs.kV = 0.12; // apply 12 V for a target velocity of 100 rps
// PID runs on position
slot0Configs.kP = 4.8;
slot0Configs.kI = 0;
slot0Configs.kD = 0.1;
// set Motion Magic settings
auto& motionMagicConfigs = talonFXConfigs.MotionMagicConfigs;
motionMagicConfigs.MotionMagicCruiseVelocity = 80; // 80 rps cruise velocity
motionMagicConfigs.MotionMagicAcceleration = 160; // 160 rps/s acceleration (0.5 seconds)
motionMagicConfigs.MotionMagicJerk = 1600; // 1600 rps/s^2 jerk (0.1 seconds)
m_talonFX.GetConfigurator().Apply(talonFXConfigs, 50_ms);
// periodic, run Motion Magic with slot 0 configs,
// target position of 200 rotations
m_motmag.Slot = 0;
m_motor.SetControl(m_motmag.WithPosition(200_tr));
|
Motion Profiling#
Closed-loop control requests have been expanded to support motion profiles generated by the robot controller.
// class member variable
final PositionVoltage m_position = new PositionVoltage(0);
// Trapezoid profile with max velocity 80 rps, max accel 160 rps/s
final TrapezoidProfile m_profile = new TrapezoidProfile(
new TrapezoidProfile.Constraints(80, 160)
);
// Final target of 200 rot, 0 rps
TrapezoidProfile.State m_goal = new TrapezoidProfile.State(200, 0);
TrapezoidProfile.State m_setpoint = new TrapezoidProfile.State();
// robot init, set slot 0 gains
var slot0Configs = new Slot0Configs();
slot0Configs.kS = 0.24; // add 0.24 V to overcome friction
slot0Configs.kV = 0.12; // apply 12 V for a target velocity of 100 rps
slot0Configs.kP = 4.8;
slot0Configs.kI = 0;
slot0Configs.kD = 0.1;
m_talonFX.getConfigurator().apply(Slot0Configs, 0.050);
// periodic, update the profile setpoint for 20 ms loop time
m_setpoint = m_profile.calculate(0.020, m_setpoint, m_goal);
// apply the setpoint to the control request
m_position.Position = m_setpoint.position;
m_position.Velocity = m_setpoint.velocity;
m_motor.setControl(m_position);
// class member variable
controls::PositionVoltage m_position{0_tr};
// Trapezoid profile with max velocity 80 rps, max accel 160 rps/s
frc::TrapezoidProfile<units::turns> m_profile{{80_tps, 160_tr_per_s_sq}};
// Final target of 200 rot, 0 rps
frc::TrapezoidProfile<units::turns>::State m_goal{200_tr, 0_tps};
frc::TrapezoidProfile<units::turns>::State m_setpoint{};
// robot init, set slot 0 gains
configs::Slot0Configs slot0Configs{};
slot0Configs.kS = 0.24; // add 0.24 V to overcome friction
slot0Configs.kV = 0.12; // apply 12 V for a target velocity of 100 rps
slot0Configs.kP = 4.8;
slot0Configs.kI = 0;
slot0Configs.kD = 0.1;
m_talonFX.GetConfigurator().Apply(slot0Configs, 50_ms);
// periodic, update the profile setpoint for 20 ms loop time
m_setpoint = m_profile.Calculate(20_ms, m_setpoint, m_goal);
// apply the setpoint to the control request
m_position.Position = m_setpoint.position;
m_position.Velocity = m_setpoint.velocity;
m_motor.SetControl(m_position);