In contrast to microcontrollers (MCUs) that use lookup table to approximate algorithms, DSPs have hardware arithmetic capability that allows real-time execution of algorithms. The need for real-time processing of high data-rate analog parameters is causing more and more engineers to evaluate DSP technology for applications that were previously in the MCU domain. DSP performance is rated in millions of instructions per second (MIPS), millions of operations per second (MOPS), and millions of multiply accumulates per second (MMAC). The overwhelming share of DSP sales this year are for wireless applications (typically cell phones), but we found some other noteworthy applications for DSP technology.
SENSING AND MOTION CONTROL
Dr. Robot Inc., Humanoid Robot HR6. The Humanoid Robot has a total of 24 degree of freedoms, each controlled by an independent motor. Standing about 52 cm (20 inches) in height and weighing 4.8 kg (10.6 lbs), the robot is enabled by a color camera, a microphone and stereo audio output, and a multitude of sensors. Freescale Semiconductor's 56F83xx hybrid controller—with up to 60 MIPS, two quadrature decoders, and two six-channel PWM modules—handles sensing and motion control, taking input from numerous sensors including a bidirectional accelerometer that provides fast response and precise acceleration measurements in the X and Y axes. For more information on Freescale Semiconductor's 56F8355 DSP, go tohttp://rbi.ims.ca/3857-541.
Roku Sound Bridge Network Music Player. The SoundBridge connects a stereo or powered speakers to a computer's digital music library to play Mac or PC digital music files anywhere in the house. DSP technology using a high-quality 24-bit DAC provides digital audio signal to noise ratio of greater than 96 dB and a dynamic range that exceeds 104 dB with a frequency response from 20 Hz to 20 kHz. Roku engineers relied on the performance of Analog Devices BF531 (up to 400 MHz/800 MMACs) to enable multichannel audio in their application. For more information on Analog Devices' BF531, go tohttp://rbi.ims.ca/3857-542.
Visteon's Mach® MP3 Entertainment. The MACH MP3 Music System provides in-car digital entertainment from a state-of-the-art MP3 player combined with an in-dash CD player/radio. Visteon engineers selected Philips' mixed-signal DSP IC technology to provide 56 to 320 kbps and variable bit rates and to read up to 255 MP3 songs in 253 user-defined directories. An example of Philips' automotive software radio DSP technology is the SAF7730 that combines analog and digital blocks (mixed signal) to provide analog IF input, digital radio reception and audio processing, sample rate converters, and digital and analog audio output. In this unit, signal processing is performed completely in software. For more information on Philips Semiconductor DSPs, go tohttp://rbi.ims.ca/3857-543.
ACTIVE DAMPING SYSTEM
Reactec Vibration Control System . This vibration control system is based on a magneto-rheological material that, when exposed to an electromagnetic field, changes its viscosity. Using this material, the system is able to automatically detect resonance and adjust damping levels at least 2,000 times a second with very low power requirements (&250 mW). Reactec engineers utilized the skyhook algorithm, the same type of approach used for the adaptive damping system in Mercedes' Maybach, to calculate and compare sensor data to reduce vibration. Without requiring statistical knowledge of the operating environment, the unit provides true adaptability and optimal operation. The algorithm is executed in a Microchip dsPIC that has 16-bit wide data path with 24-bit wide instructions, several motor-control specific peripherals, and 30 MIPS. For more information on Microchip's dsPIC family, go tohttp://rbi.ims.ca/3857-545.
Merloni Ariston Washing Machine. The Ariston washing machine is front-loaded and load-optimized to save water and power and uses an efficient three-phase ac motor. Merloni engineers chose a Texas Instruments' DSP for implementing field-oriented control (FOC) and other motor control aspects. Designed for ac induction, brushless dc, switched reluctance, and stepper motor control, the TMS320LF2401A is a low-cost, 16-bit, 40 MIPS fixed-point DSP-based controller with several features for simplifying complex motor control. This includes an integrated single-cycle multiplier, seven pulse width modulation (PWM) variable frequency and dead-time ports, five ultra-rapid 10-bit analog to digital converters (ADCs), and Flash memory. For more information on TI's TMS320LF2401A digital signal controller, go tohttp://rbi.ims.ca/3857-544.