TI DSCs Bring Performance and Integration For Real-time Acoustic Triangulation In Team SONIA’s Autonomous Underwater Vehicle

We began development using traditional microcontrollers (MCU), but quickly switched to TI's F28x controllers when we realized we needed a combination of performance, peripherals and integration to create a smaller, more compact AUV that could still pack a punch in terms of performance, said Félix Pageau, team leader of SONIA AUV project.

Thanks to these benefits, plus the flexibility inherent in the controller’s programmable digital technology, our overall development was simplified and we were able to vastly reduce the size and complexity of the vehicles’ electronics system, said Francis Lauzon-Duranceau, passive SONAR project leader.

The SONIA submersible craft combines a battery, thrusters, on-board computer and other electronics in a compact hull that can be carried by a single person. The AUV is equipped with a robotic camera and vision recognition software to detect shapes and colors, active SONAR that uses low-frequency pings to detect depth and objects, and passive SONAR with hydrophones that detect mid-frequency sounds emitted by other objects.

Received sounds are converted to digital acoustic data, which is then triangulated by the 32-bit TMS320F2812 controller and used in combination with an internal compass and gyroscope to orient the craft.

150 MIPS of DSP-based computational performance allows the F2812 controller to manage all real-time acoustic triangulation, freeing processing headroom in the main computer for visual recognition.

Extending Unmanned Vehicles to New Underwater Environments The International AUV Competition is sponsored by the Association for Unmanned Vehicle Systems International (AUVSI) and the U.S. Office of Naval Research (ONR), and was developed to promote the development of systems that use artificial intelligence to perform complex or dangerous underwater tasks with no human intervention or communication such as detecting and disarming underwater mines, performing security and contraband searches in harbors and laying optical fiber on sea beds.

Competition tasks include: locating a docking station in murky water via flashing lights, following pipelines, dropping markers in bins representing pipeline breaks and surfacing over an acoustic beacon.

During the 9th Annual AUV Competition in 2006, SONIA’s guidance capabilities and artificial intelligence software enabled the team’s craft to complete all tasks within the allowed 15 minutes, securing a finish among the top three contestants. For the 2007 competition, however, the SONIA team has redesigned their vehicle to feature additional navigation sensors, be more lightweight, more aware of its environment and easier to maintain than previous AUVs. For more information on the SONIA AUV project, please see http://sonia.etsmtl.ca

DSP Technology Enables Innovative Control Solutions TI’s 32-bit TMS320C28x™ controller platform features up to 150 MIPS of performance and an integrated, control-optimized peripheral mix that includes TI’s patent pending high-resolution pulse width modulation (HRPWM) technology, with 150 pico-second (ps) resolution.

This enhanced resolution allows faster control loops and quicker system response as well as more accurate control systems such as those found in the SONIA AUV. Among the F2812 device’s integrated peripherals are a fast, 12.5 MSPS, 12-bit analog-to-digital converter (ADC), timers, data and external memory interfaces, pulse-width modulation (PWM) and a CAN control bus interface. In addition, the devices’ on-chip memory is available for program and data storage while the controller’s industrial characterization assures reliable operation over the wide temperature ranges that can be found in different underwater environments.

Additionally, the F2812 controller’s programmability helped shift the development emphasis from hardware to software – playing to the strength of the team in programming. The controller’s extensive support library and the Code Composer Studio™ integrated development environment (IDE) simplified writing code and helped save an estimated 50 percent of program development time. As the SONIA team continues to improve their AUV’s overall design for future contests, they can easily modify the DSP algorithms as needed. For more information on the full line of TMS320C2000™ digital signal controllers, see www.ti.com/c2000. The SONIA AUV also includes TI op amps and voltage regulators. For more information on TI Analog products, please see www.ti.com/analog.

TI Enables Innovation with Broad Range of Controllers From ultra-low-power MSP430 and 32-bit general purpose TMS470 ARM7® family-based MCUs to high performance TMS320C2000 digital signal controllers, TI offers designers the broadest range of embedded control solutions. Designers can also accelerate their design to market by tapping into TI’s complete software and hardware tools, extensive third party offerings and technical support. For more information on the broad range of TI’s controllers, see www.ti.com/mcu.