APM:Rover 2.46 released

The ardupilot development team is proud to announce the release of version 2.46 of APM:Rover. This is a major release with a lot of new features and bug fixes.

This release is based on a lot of development and testing that happened prior to the AVC competition where APM based vehicles performed very well.

Full changes list for this release:

[ul][li]added support for higher baudrates on telemetry ports, to make it easier to use high rate telemetry to companion boards. Rates of up to 1.5MBit are now supported to companion boards.[/li]
[li]new Rangefinder code with support for a wider range of rangefinder types including a range of Lidars (thanks to Allyson Kreft)[/li]
[li]added logging of power status on Pixhawk[/li]
[li]added PIVOT_TURN_ANGLE parameter for pivot based turns on skid steering rovers[/li]
[li]lots of improvements to the EKF support for Rover, thanks to Paul Riseborough and testing from Tom Coyle. Using the EKF can greatly improve navigation accuracy for fast rovers. Enable with AHRS_EKF_USE=1. [/li]
[li]improved support for dual GPS on Pixhawk. Using a 2nd GPS can greatly improve performance when in an area with an obstructed view of the sky[/li]
[li]support for up to 14 RC channels on Pihxawk[/li]
[li]added BRAKING_PERCENT and BRAKING_SPEEDERR parameters for better breaking support when cornering[/li]
[li]added support for FrSky telemetry via SERIAL2_PROTOCOL parameter (thanks to Matthias Badaire)[/li]
[li]added support for Linux based autopilots, initially with the PXF BeagleBoneBlack cape and the Erle robotics board. Support for more boards is expected in future releases. Thanks to Victor, Sid and Anuj for their great work on the Linux port. [/li]
[li]added StorageManager library, which expands available FRAM storage on Pixhawk to 16 kByte. This allows for 724 waypoints on Pixhawk.[/li]
[li]improved reporting of magnetometer and barometer errors to the GCS[/li]
[li]fixed a bug in automatic flow control detection for serial ports in Pixhawk[/li]
[li]fixed use of FMU servo pins as digital inputs on Pixhawk[/li]
[li]imported latest updates for VRBrain boards (thanks to Emile Castelnuovo and Luca Micheletti)[/li]
[li]updates to the Piksi GPS support (thanks to Niels Joubert)[/li]
[li]improved gyro estimate in DCM (thanks to Jon Challinger)[/li]
[li]improved position projection in DCM in wind (thanks to Przemek Lekston)[/li]
[li]several updates to AP_NavEKF for more robust handling of errors (thanks to Paul Riseborough)[/li]
[li]lots of small code cleanups thanks to Daniel Frenzel[/li]
[li]initial support for NavIO board from Mikhail Avkhimenia[/li]
[li]fixed logging of RCOU for up to 12 channels (thanks to Emile Castelnuovo)[/li]
[li]code cleanups from Silvia Nunezrivero[/li]
[li]improved parameter download speed on radio links with no flow control[/li][/ul]

Many thanks to everyone who contributed to this release, especially Tom Coyle and Linus Penzlien for their excellent testing and feedback.

Happy driving!

Hi All,
I am especially pleased with the Active Braking that employs the new BRAKING_PERCENT and BRAKING_SPEEDERR along with the existing SPEED_TURN_GAIN and SPEED_TURN_DIST parameters.

Using Active Braking I was able to approach a turn at around 9m/s and have the rover decrease its speed to around 4 - 5m/s in less than 5m and complete the turn without skidding or rolling over.

I basically used a BRAKING_PERCENT of 75 and a BRAKING_SPEEDERR of 1m/s combined with a SPEED_TURN_GAIN of ~50% of my CRUISE_SPEED and a SPEED_TURN_DIST of 3 - 5 m for my Traxxas Slash 4WD test bed rover.

As is usual, members will have to experiment with these parameters to obtain the best performance from their own rovers:-)



Is the software and hardware taking in count different terrain properties? If I compare driving on asphalt and driving in grass - speed is different (speed % declared vs actual speed), turn radius is different etc.

Do I need to tune my rover for different conditions or is there a way or an idea how to make this more automated? If I drive slowly (55T motor traxxas slash 4x4, 50% speed) on grass, repetitive accuracy is really good ~0,5m to 1m, when driving at 70% speed on grass relative accuracy drifts a lot.

You could create different Full Parameter Lists with one with tuning for asphalt and one with tuning for grass and load whichever parameter list for the environment you will be operating in.

Please fix the Sonar sensor problem in the firmware.

More info about the topic:
diydrones.com/forum/topics/how-t … 2#comments