USU 7/16 Operation Overview Altitude measurement based on barometric pressure is a function of temperature The MS5534A Digital Barometer senses both pressure and temperature Both pressure and temperature outputs are converted from analog to digital on-chip
USU 8/16 Operation Overview (cont.) Outputs: Pressure: 16 bit number “D1” Temperature: 16 bit number “D2” Each sensor is factory calibrated at two pressures and temperatures. This gives two constants. Pressure, Temperature, and the constants are used off-chip to calculate the altitude
USU 15/16 Altitude readout steps 1. Word 1 to Word 4 are read out of the serial interface. 2. Compensation coefficients C1 to C6 are extracted through the serial interface. 3. Then the 16 bit pressure and 16 bit temperature numbers can be read out in a loop. 4. Altitude is calculated from pressure, temperature, and the constants off-chip.
USU 19/16 Arrangement of calibration data in word1 to word4
USU 20/16 Method for compensating for non- linearity
USU 21/16 Serial interface The altimeter communicates with the rest of the system via a 3 wire serial interface SCLK (serial clock) initiates that data transfer Bits are sampled and sent on the rising edge of SCLK Transactions are initiated by a code sent to the altimeter on the DIN line Responses are sent back on the DOUT line
28 Actuator: SQL Series Linear Motors Seth Young Mecatronics March 2006
USU 29/16 Features: Piezoelectric motor Scalable to millimeters in size Simple construction for high-volume, low-cost manufacturing Direct linear movement
USU 30/16 Features (cont.): Robust construction to withstand high shock loads Sub-micrometer precision Silent, ultrasonic operation Wide operating temperature range
USU 31/16 Overview SQL series linear SQUIGGLE motors are very small and have low power requirements. Because of this they are great for medical devices that are portable. They can withstand high shock. They also offer sub- micrometer precision and can supply up to four Newtons of force.
USU 33/16 Advantages of the Squiggle motor Electromagnetic motors have reached the limit of minimization In EM motors, more power is converted to heat than motion in motors smaller than 6mm There is less torque to overcome friction in the micro-gears
USU 34/16 Advantages of the Squiggle motor Squiggle motor gives greater efficiency for power Higher reliability Ten times better precision than EM motors
USU 36/16 Design Fundamentally threaded nut and screw Two-phase sinusoidal drive signals cause piezoelectric actuators to vibrate the nut at fixed resonate frequency Because it’s ultrasonic it’s very quiet
USU 37/16 Design (cont.) The nut vibrates in a “hula hoop” motion The screw translation is bidirectional and the position of the tip of the screw is precisely controlled by the driver A position sensor is required to achieve repeatable steps.
USU 38/16 Design (cont.) The vibration stops at zero power and the threads hold position with very high stability and stiffness. Battery power is preserved because the screws stay in position without continuous power.
USU 48/16 MC-1000 Resonant Drive Board and HS-1000 Handset Drive board demonstrates a circuit that can be put onto an ASIC Operates a single SQL motor and can be controlled by a handset Uses a Microchip dsPIC30F3010 microprocessor at 20 MIPS
USU 49/16 MC-1000 Resonant Drive Board and HS-1000 Handset
USU 50/16 MC-1000 Resonant Drive Board and HS-1000 Handset