If you are planning to visit the 28C3 as last year some of us are there. This time though we have a dedicated table on the upper floor, and should be easier to find. We will be very happy if you come by and say hi!

Another shameless plug from JobyRobotics. After many months of hard work we have finally reached a version of Lisa/M that is ready for a wider range of developers – you can get it in the JobyRobotics shop. Although there are still some things missing that would let a beginning user use it with ease, we decided it is better to provide it to all of the other brilliant non core developers and users. You can find out more about it in the Paparazzi Wiki. A big thanks go to OpenUAS for his great help with the documentation.

And before you start asking, it is not fully Open-Hardware YET! The schematics are available in the SVN as well as in the Wiki. The eagle board layout files will follow soon, as has been the case with all other hardware developed by JobyRobotics.

Let us know what you plan to build with this autopilot. Also if you have built an aircraft with Lisa/L or Aspirin we would be very happy to see them. Just drop a comment below with a link to a picture. Let’s spread the word of what is possible with Paparazzi!!!

Let’s get flying!

Cheers Esden

Besides its small size Aspirin is cheaper then the Booz IMU you already know. The use of all digital sensors reduces size, cost and complexity while simplifying calibration.

Aspirin provides 9 degrees of measurement (DOM): 3 axis linear acceleration, 3 axis angular velocity, and 3 axis magnetic field measurement.

It consists of:

• 3 axis accelerometer (ADXL345)
• 3 axis gyroscope (IMU-3000)
• 3 axis magnetometer (HMC5843)

This IMU is ready for the next generation Lisa/M autopilot that we wrote about before. The module fits directly on Lisa/M without the need of a carrier board.

We did not add an MCU on the board to save space, reduce cost, and improve latency behavior when connected to an autopilot. You have direct access to the sensor busses.

Aspirin uses the latest generation of Invensense 3 axis MEMS gyroscopes. IMU-3000′s advantage over other sensors (such as ITG-3200 found in similar IMU designs) is its selectable range. Selectable range allows the user to obtain maximum resolution and optimum performance, depending on vehicle dynamics and desired flight mode. No longer will it be necessary to limit vehicle dynamics to 300º/s, as Aspirin’s gyroscopes have a range of up to 2000º/s.

Aspirin IMU are available now in the Joby Robotics online shop.

As a side note, Joby Robotics also has crimped picoblade wires in 10 different colors. So you don’t have to acquire an expensive crimp tool and you are not stuck to only red colored wire. You can find those in the Wires and Friends section.

Here a small video of a Quad with Lisa/L autopilot with Aspirin IMU running Paparazzi rotorcraft firmware, for some additional entertainment. Have fun!

Cheers your Paparazzi team.

Just to give you guys a heads up. Several of the Paparazzi core developers are planning to go to the Chaos Communication Camp 2011 in Finowfurt (near Berlin) in Germany. The event will last for the 4 days 10|11|12|13|14th August 2011. If you have a chance be sure to visit us there. We plan to release some really cool new things at the event. I am sure if you are interested in UAV, Multicopter or Aircraft you will not want to miss this!

We hope to see you there!

Cheers, your Paparazzi Team.

Although this release is a couple of weeks later than expected, the team is satisfied that this port will be easy to install and run. This first release still retains the look and feel of its Linux sibling as currently it uses X windows for rendering. This is due to change, as the graphics library used by Paparazzi (GTK+) is improving its support for the native quartz engine found in Mac OSX. This improved version of GTK+ is due for release at the beginning of March. The team are tracking this and expect a more native look and feel version of Paparazzi to follow this release.

The porting team has taken particular care to implement the packages as Macport ports thus giving a user the opportunity to install source versions or binary versions. Ensuring that every feature of paparazzi is available as it becomes available.

Again I am pleased to see the depth of talent in the Paparazzi team. Bernard Davison a relative newcomer to Paparazzi development made a huge contribution to the packaging of this port. Enough of the waffle though! The download install page for Paparazzi on OSX can be found at http://paparazzi.enac.fr/wiki/InstallationMacOSX

Cheers, your Paparazzi development team.

Felix gave an interview about Paparazzi to Projectmovie 2010. It is in German but the makers of the movie are planning to add English subtitles to the movie at some point.

Cheers your Paparazzi Team

Lisa/M Bottom

As promised, we want to talk about projects we are currently working on. One of them is Lisa/M.

Lisa/M will be the medium sized Autopilot based on the STM32 Cortex-M3 microcontroller. It is part of the Lisa series of Autopilots. It is very small (50mm x 25mm), about the size of an RC receiver. We want it to be as affordable as possible so that more people can join the autonomous aircraft revolution. The final cost still needs to be determined, as we are not done with the development yet.

Due to its large capabilities and small size, it can be used as a full Autopilot for fixed wing airplanes, multicopters and helicopters, as well as an IO extender/repeater (in which case the IMU can be left out, cutting the cost significantly).

One other interesting feature is that it can host the SMD mounted Aspirin IMU without adding size. The Aspirin IMU is the next generation small, flat, low part count and cheap IMU that will get an article by itself.

Lisa/M features a multitude of interfaces:

• CAN serial
• USB
• SPI serial
• I2C serial
• 2 RS232 3V3 and 5V TTL level (UART)
• 6 PWM servo outputs
• 7 analog inputs
• 3 general purpose digital in-/out-puts

Lisa/M with mounted IMU has the following sensors on board:

• 3 Axis Gyroscope
• 3 Axis Accelerometer
• 3 Axis Magnetometer
• Pressure sensor

The pressure sensor is mounted directly on Lisa/M as this sensor is not provided by Aspirin. Without a GPS unit you have all necessary sensors for full attitude and altitude stabilization in an extremely small package (if you know of a smaller one, let us know!). With an external GPS unit, it is a full fledged Autopilot.

Now you may ask when will it be available for prime time. We can’t give you a definite answer. What we definitely can say is that it will be as soon as it is ready.

But now seriously. We are currently working on the second revision of our prototypes. Based on our experience it takes 3 to 4 revisions of a hardware design to get it right. That means in a few months if everything goes well.

Don’t lose faith though. The first design was already good enough to be able to fly an airplane. That means that there are no major mistakes in the design.

We will of course keep you up to date on this project progress in future articles.

Cheers … your Paparazzi team.

The first video shows Paparazzi’s adaptive control loops (written by Pascal Brisset and Gautier Hattenberger at ENAC) for fixedwing aircraft keeping a Multiplex Twinstar on track, despite dropping a portion of the right wing and aileron and then switching the right motor off.

Martin Mueller equipped the Twinstar with video cameras to document this. You can easily see that after part of the right wing is dropped the adaptive controller compensates for this automatically although only 50% of the aileron control surface remains. To make things even worse, the motor on the same side was switched off to simulate engine failure but the autopilot manages to keep it stable. At that point the aircraft became virtually impossible to fly by the very skilled safety pilot in manual control.

Although the adaptive vertical control for multicopters (by Antoine Drouin at ENAC) has been around for almost two years now, here is a demo of a Paparazzi Booz quadrotor suddenly dropping 50% off its weight.

In this case, a Kalman filter of dimension one is used to estimate the the ratio of vertical acceleration over the produced thrust. This basically equates to the inverse of the mass during flight. Then the inverted dynamic model is used to issue a nominal thrust command based on this estimate. With this the quadrotor is able to stay very near same height, whereas with standard feedback control loops it would “go through the roof” when the payload is suddenly dropped.

Cheers, your Paparazzi Team

In the case of Lisa/L the 64 pin STM32F103RE processor has 64k of RAM, 512k of FLASH and runs at 72Mhz. To ensure that future autopilot features are not restricted by board design, Antoine has ensured that all of the processor’s pins are exposed on Molex PicoBlade connectors. This allows access to all of the available peripherals, which include 3 USARTS, 2 SPI, 2 I2C, 1 CAN and 3 ADC channels and many more.

The board also provides an interface which is both electronically and mechanically compatible with that of the Gumstix Overo, providing the option of running autopilot code (and any other applcations) under Embedded Linux on an Overo with the STM32 acting as an I/O processor.

Lisa/L showing Gumstix Overo connector

The board is equipped with a pair of pressure sensors, one absolute to measure altitude and one differential to measure airspeed. Additionally, Lisa/L is fully compatible with the BOOZ IMU module which can be conveniently mounted above the Lisa/L board.

The addition of further sensors and external peripherals like modems, servos, USB webcams or wifi sticks is facilitated through the inclusion of three different power supplies (5V for external peripherals, 3V3 for avionics and a linear supply to provide clean power to sensitive sensors).

For the first time in a Paparazzi autopilot board, a USB based JTAG interface to the STM32 has been incorporated. This high speed interface allows for both fast programming and run time debugging using GDB. Debugging doesn’t get any easier . If the Gumstix module is mounted, this USB interface also provides the serial console.

Even from these few short paragraphs, it should be apparent that Lisa/L has been designed with power and flexibility in mind. This has already demonstrated with the flight of both quadrocopters, hexacopters and fixed wing aircraft utilising very different sensor suites (such as the Paparazzi Booz IMU and Paparazzi IR sensors ).

For those that can’t wait until next time the Lisa/L Gallery is a must see.

In the upcoming articles we will explore the features of Lisa/L further.

If you want to get hands on a Lisa/L right away the Joby Robotics shop is the place to go. They will provide you with everything you need to get you going.

Until next time… Your Paparazzi Team