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458 lines
28 KiB
Markdown
458 lines
28 KiB
Markdown
# Configuration/Tuning (Ackermann Rover)
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This topic provides a step-by-step guide for setting up your [Ackermann rover](../frames_rover/ackermann.md).
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Successive steps enable [drive modes](../flight_modes_rover/ackermann.md) with more autopilot support and features.
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:::warning
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Each step is dependent on the previous steps having been completed.
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Modes will only work properly if the preceding modes have been configured.
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:::
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## Basic Setup
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To configure the Ackermann rover frame and outputs:
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1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
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Note that this is a special build that contains rover-specific modules.
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2. In the [Airframe](../config/airframe.md) configuration select the _Generic Rover Ackermann_:
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Select the **Apply and Restart** button.
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::: info
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If this airframe is not displayed and you have checked that you are using rover firmware (not the default), you can alternatively enable this frame by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `51000`.
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:::
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3. Open the [Actuators Configuration & Testing](../config/actuators.md) to map the steering and throttle functions to flight controller outputs.
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## Ручний режим
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:::warning
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For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
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:::
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The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode).
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This mode is also affected by (optional) acceleration/deceleration limits.
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As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
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Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
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1. [RA_WHEEL_BASE](#RA_WHEEL_BASE) [m]: Measure the distance from the back to the front wheels.
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2. [RA_MAX_STR_ANG](#RA_MAX_STR_ANG) [deg]: Measure the maximum steering angle.
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3. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
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:::info
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This parameter is also used for the feed-forward term of the speed control.
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It will be further tuned in the configuration of [Position mode](#position-mode).
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:::
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4. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
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<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
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:::tip
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Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
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This may or may not be appropriate for your vehicle and use case.
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One approach to determine an appropriate value is:
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1. From a standstill, give the rover full throttle until it reaches the maximum speed.
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2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
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3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
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Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
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If that is the case:
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1. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
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2. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
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3. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
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:::
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5. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
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:::tip
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The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
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:::
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:::info
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This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
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:::
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6. (Optional) [RA_STR_RATE_LIM](#RA_STR_RATE_LIM) [deg/s]: Maximum steering rate you want to allow for your rover.
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:::tip
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This value depends on your rover and use case.
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For bigger rovers there might be a mechanical limit that is easy to identify by steering the rover at a standstill and increasing
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[RA_STR_RATE_LIM](#RA_STR_RATE_LIM) until you observe the steering rate to no longer be limited by the parameter.
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For smaller rovers you might observe the steering to be too aggressive. Set [RA_STR_RATE_LIM](#RA_STR_RATE_LIM) to a low value and steer the rover at a standstill.
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Increase the parameter until you reach the maximum steering rate you are comfortable with.
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:::
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:::warning
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A low maximum steering rate makes the rover worse at tracking steering setpoints, which can lead to a poor performance in the subsequent modes.
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:::
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## Acro Mode
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:::warning
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For this mode to work properly [Manual mode](#acro-mode) must've already been configured!
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:::
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To set up [Acro mode](../flight_modes_rover/ackermann.md#acro-mode) configure the following [parameters](../advanced_config/parameters.md) in QGroundControl:
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1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM): Maximum yaw rate you want to allow for your rover.
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:::tip
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Limiting the yaw rate is necessary if the rover is prone rolling over, loosing traction at high speeds or if passenger comfort is important.
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Small rovers especially can be prone to rolling over when steering aggressively at high speeds.
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If this is the case:
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1. In [Acro mode](../flight_modes_rover/ackermann.md#acro-mode), set [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) to a small value and drive the rover at full throttle and with the right stick all the way to the left or right.
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2. Increase [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) until the wheels of the rover start to lift up.
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3. Set [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) to the highest value that does not cause the rover to lift up.
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If you see no need to limit the yaw rate, set this parameter to the maximum yaw rate the rover can achieve:
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1. In [Manual mode](#manual-mode) drive the rover at full throttle and with the maximum steering angle.
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2. Plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and enter the highest observed value for [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM).
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:::
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2. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
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The closed loop acceleration control will compare the yaw rate setpoint with the measured yaw rate and adapt the motor commands based on the error between them.
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The proportional gain is multiplied with this error and that value is added to the motor command.
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This compensates for disturbances such as uneven ground and external forces.
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:::tip
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To tune this parameter:
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1. Put the rover in [Acro mode](../flight_modes_rover/ackermann.md#acro-mode) and hold the throttle stick and the right stick at a few different levels for a couple of seconds each.
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2. Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
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3. Increase [RO_YAW_RATE_P](#RO_YAW_RATE_P) if the measured value does not track the setpoint fast enough or decrease it if the measurement overshoots the setpoint by too much.
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4. Repeat until you are satisfied with the behaviour.
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:::
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3. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw rate controller.
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The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
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::: tip
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An integrator might not be necessary at this stage, but it will become important for subsequent modes.
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:::
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The rover is now ready to drive in [Acro mode](../flight_modes_rover/ackermann.md#acro-mode).
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## Stabilized Mode
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:::warning
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For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
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:::
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For [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
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Unlike the closed loop yaw rate, this controller has no feed-forward term.
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Therefore you only need to tune the closed loop gains:
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1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
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::: tip
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In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
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To tune it start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
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Put the rover into stabilized mode and move the left stick of your controller up to drive forwards.
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Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
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Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
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:::
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:::info
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For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
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Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller. If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
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:::
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The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/ackermann.md#stabilized-mode).
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## Position Mode
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:::warning
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For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
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:::
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[Position mode](../flight_modes_rover/ackermann.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate and speed control and leveraging position estimates.
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To configure set the following parameters:
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1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
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This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
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2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
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As mentioned in the [Manual mode](../flight_modes_rover/ackermann.md#manual-mode) configuration , a good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode).
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<a id="RA_SPEED_TUNING"></a>
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::: tip
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To further tune this parameter:
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1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
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This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
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2. Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
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3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
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4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
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If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
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:::
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::: info
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If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/ackermann.md#position-mode), set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
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:::
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3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
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::: tip
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This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RA_SPEED_TUNING).
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If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
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:::
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4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
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::: tip
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For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
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:::
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5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (right stick centered) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
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This parameter determines how aggressive the controller will steer towards the path.
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::: tip
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Decreasing the parameter makes it more aggressive but can lead to oscillations.
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To tune this:
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1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
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2. Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
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3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
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4. Repeat until you are satisfied with the behaviour.
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:::
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6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
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::: tip
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Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
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:::
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7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
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::: tip
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Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
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:::
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The rover is now ready to drive in [Position mode](../flight_modes_rover/ackermann.md#position-mode).
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## Auto Modes
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:::warning
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For auto modes to work properly [Manual Mode](#manual-mode), [Acro mode](#acro-mode)and [Position mode](#position-mode) must already be configured!
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:::
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<a id="pure_pursuit_controller"></a>
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In [auto modes](../flight_modes_rover/ackermann.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
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The required parameter configuration is discussed in the following sections.
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### Speed
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1. [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2] and [RO_JERK_LIM](#RO_JERK_LIM) [m/s^3] are used to calculate a speed trajectory such that the rover reaches the next waypoint with the correct [cornering speed](#cornering-speed).
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::: tip
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Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
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- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
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- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
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These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
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:::
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2. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
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If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
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### Corner Cutting
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The module employs a special cornering logic causing the rover to "cut corners" to achieve a smooth trajectory.
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This is done by scaling the acceptance radius based on the corner the rover has to drive (for geometric explanation see [Cornering logic](#mission-cornering-logic-info-only)).
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The degree to which corner cutting is allowed can be tuned, or disabled, with the following parameters:
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:::info
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The corner cutting effect is a tradeoff between how close you get to the waypoint and the smoothness of the trajectory.
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1. [NAV_ACC_RAD](#NAV_ACC_RAD) [m]: Default acceptance radius
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This is also used as a lower bound for the acceptance radius scaling.
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2. [RA_ACC_RAD_MAX](#RA_ACC_RAD_MAX) [m]: The maximum the acceptance radius can be scaled to.
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Set equal to [NAV_ACC_RAD](#NAV_ACC_RAD) to disable the corner cutting effect.
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3. [RA_ACC_RAD_GAIN](#RA_ACC_RAD_GAIN) [-]: This tuning parameter is a multiplicand on the [calculated ideal acceptance radius](#corner-cutting-logic) to account for dynamic effects.
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:::tip
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Initially set this parameter to `1`.
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If you observe the rover overshooting the corner, increase this parameter until you are satisfied with the behaviour.
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Note that the scaling of the acceptance radius is limited by [RA_ACC_RAD_MAX](#RA_ACC_RAD_MAX).
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:::
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### Path Following
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The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a yaw rate setpoint for the vehicle that is then close loop controlled.
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The close loop yaw rate was tuned in the configuration of the [Acro mode](#acro-mode), and the pure pursuit was tuned when setting up the [Position mode](#position-mode).
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During any auto navigation task observe the behaviour of the rover.
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If you are unsatisfied with the path following, there are 2 steps to take:
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1. Plot the `adjusted_yaw_rate_setpoint` and the `measured_yaw_rate` from the [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
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If the tracking of these setpoints is not satisfactory adjust the values for [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I).
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2. Plot the `adjusted_yaw_setpoint` and the `measured_yaw` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) over each other.
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If the tracking of these setpoints is not satisfactory adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
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3. Steps 1 and 2 ensures accurate setpoint tracking, if the path following is still unsatisfactory you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
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## Pure Pursuit Guidance Logic
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The desired yaw setpoints are generated using a pure pursuit algorithm.
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The controller takes the intersection point between a circle around the vehicle and a line segment.
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In mission mode this line is usually constructed by connecting the previous and current waypoint.
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The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
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The look-ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
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It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
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:::info
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A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
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:::
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The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
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If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
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To summarize, the following parameters can be used to tune the controller:
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| Параметр | Опис | Unit |
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| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
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| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
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| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
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| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
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## Mission Cornering Logic (Info only)
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### Corner Cutting Logic
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To enable a smooth trajectory, the acceptance radius of waypoints is scaled based on the angle between a line segment from the current-to-previous and current-to-next waypoints.
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The ideal trajectory would be to arrive at the next line segment with the heading pointing towards the next waypoint.
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For this purpose the minimum turning circle of the rover is inscribed tangentially to both line segments.
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The acceptance radius of the waypoint is set to the distance from the waypoint to the tangential points between the circle and the line segments:
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$$
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\begin{align*}
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r_{min} &= \frac{L}{\sin\left( \delta_{max}\right) } \\
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\theta &= \frac{1}{2}\arccos\left( \frac{\vec{a}*\vec{b}}{|\vec{a}||\vec{b}|}\right) \\
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r_{acc} &= \frac{r_{min}}{\tan\left( \theta\right) }
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\end{align*}
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$$
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| Symbol | Опис | Unit |
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| ----------------------------------- | ---------------------------------- | ---- |
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| $\vec{a}$ | Vector from current to previous WP | m |
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| $\vec{b}$ | Vector from current to next WP | m |
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| $r_{min}$ | Minimum turn radius | m |
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| $\delta_{max}$ | Maximum steer angle | m |
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| $r_{acc}$ | Acceptance radius | m |
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### Cornering Speed
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To smoothen the trajectory further and reduce the risk of the rover rolling over, the rover speed is regulated as follows:
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1. During cornering the rover drives at the following speed:
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<!-- prettier-ignore -->
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$$v_{cor, max} = \dot{\psi}_{max} \cdot r$$
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with $r:$ Turning radius for the upcoming corner and $\dot{\psi}_{max}:$ Maximum yaw rate ([RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM)).
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2. In between waypoints (straight line) the rover speed is regulated such that it will arrive at the acceptance radius of the waypoint with the desired cornering speed.
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The rover is constrained between the maximum speed [RO_SPEED_LIM](#RO_SPEED_LIM) and the speed where the maximum steering angle does not cause the rover to exceed the yaw rate limit:
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<!-- prettier-ignore -->
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$$v_{min} = \frac{w_b \cdot \dot{\psi}_{max}}{tan(\delta_{max})}$$
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with $w_b:$ Wheel base ([RA_WHEEL_BASE](#RA_WHEEL_BASE)), $\dot{\psi}_{max}:$ Maximum yaw rate ([RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM)) and $\delta_{max}:$ Maximum steering angle ([RA_MAX_STR_ANG](#RA_MAX_STR_ANG)).
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## Огляд параметрів
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List of all parameters of the ackermann rover module:
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| Параметр | Опис | Unit |
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| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------- | ------- |
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| <a id="RA_WHEEL_BASE"></a>[RA_WHEEL_BASE](../advanced_config/parameter_reference.md#RA_WHEEL_BASE) | Wheel base | m |
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| <a id="RA_MAX_STR_ANG"></a>[RA_MAX_STR_ANG](../advanced_config/parameter_reference.md#RA_MAX_STR_ANG) | Maximum steering angle | deg |
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| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
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| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate | m/s^2 |
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| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
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| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
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| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
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| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed | m/s |
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| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
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| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
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| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
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| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
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| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
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| <a id="NAV_ACC_RAD"></a>[NAV_ACC_RAD](../advanced_config/parameter_reference.md#NAV_ACC_RAD) | Default acceptance radius | m |
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| <a id="RA_STR_RATE_LIM"></a>[RA_STR_RATE_LIM](../advanced_config/parameter_reference.md#RA_STR_RATE_LIM) | (Optional) Maximum allowed steering rate | deg/s |
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| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
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| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
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| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
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| <a id="RA_ACC_RAD_MAX"></a>[RA_ACC_RAD_MAX](../advanced_config/parameter_reference.md#RA_ACC_RAD_MAX) | (Optional) Maximum radius the acceptance radius can be scaled to | m |
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| <a id="RA_ACC_RAD_GAIN"></a>[RA_ACC_RAD_GAIN](../advanced_config/parameter_reference.md#RA_ACC_RAD_GAIN) | (Optional) Tuning parameter for the acceptance radius scaling | - |
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## Дивіться також
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- [Drive Modes (Ackermann Rover)](../flight_modes_rover/ackermann.md).
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