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141 lines
8.1 KiB
Markdown
141 lines
8.1 KiB
Markdown
# Basic Setup
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## Configure the rover frame and outputs
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1. Enable Rover support by flashing the [PX4 rover build](../config_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 your rover type: _Generic Rover Ackermann_/_Generic Rover Differential_/_Generic Rover Mecanum_:
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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 directly to the following value:
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| Rover Type | Value |
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| ------------ | ------- |
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| Ackermann | `51000` |
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| Differential | `50000` |
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| Mecanum | `52000` |
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:::
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3. Open the [Actuators Configuration & Testing](../config/actuators.md) to map the motor/servo functions to flight controller outputs.
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That is the minimum setup to use the rover in [Manual mode](../flight_modes_rover/manual.md#manual-mode).
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## Geometric Parameters
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Manual mode is also affected by (optional) acceleration/deceleration limits set using the geometric described below.
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These limits are mandatory for all other modes.
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Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the parameters in the group for your frame type.
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### Ackermann
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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. (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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### Differential
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1. [RD_WHEEL_TRACK](#RD_WHEEL_TRACK) [m]: Measure the distance from the centre of the right wheel to the centre of the left wheel.
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### Mecanum
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1. [RM_WHEEL_TRACK](#RM_WHEEL_TRACK) [m]: Measure the distance from the centre of the right wheel to the centre of the left wheel.
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## Speed Parameters
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1. [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 closed loop speed control.
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It will be further adjusted in the [velocity tuning](velocity_tuning.md) step.
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:::
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2. (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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3. (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 in modes that are [position controlled](position_tuning.md).
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:::
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You can now continue the configuration process with [rate tuning](rate_tuning.md).
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## Parameter Overview
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| 매개변수 | 설명 | Unit |
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| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------- | ------- |
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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_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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### Ackermann Specific
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| 매개변수 | 설명 | 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="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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### Differential Specific
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| 매개변수 | 설명 | Unit |
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| <a id="RD_WHEEL_TRACK"></a>[RD_WHEEL_TRACK](../advanced_config/parameter_reference.md#RD_WHEEL_TRACK) | Wheel track | m |
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### Mecanum Specific
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| 매개변수 | 설명 | Unit |
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| ----------------------------------------------------------------------------------------------------------------------------------------------- | ----------- | ---- |
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| <a id="RM_WHEEL_TRACK"></a>[RM_WHEEL_TRACK](../advanced_config/parameter_reference.md#RM_WHEEL_TRACK) | Wheel track | m |
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