TPC 18: World’s first MEMS ultrasonic time-of-flight sensors · 2018-11-14 · Provides 6-DoF controller tracking based on sensor fusion Fuses ultrasonic ToF with IMU acceleration/rotation

World’s first MEMS ultrasonic time-of-flight sensorsMiniature high-performance range finding, presence detection and more

Dr. David HorsleyCTO

Chirp Microsystems, Inc.A TDK Group Company

Berkeley, CA, USANovember 14, 2018

Technologies & Products Press Conference 2018

Technologies & Products Press Conference 2018 MEMS ultrasonic time-of-flight sensors © Chirp Microsystems A TDK Group Company 2018CC 11/18 2

Ultrasonic sensing today

● Measure distance by time-of-flight of an ultrasonic pulse

● Use multiple sensors to find object location (left, right, center…)

● Sense range to avoid objects and prevent collisions

● Detect human proximity and presence

Automotive • Automated guided vehicles • Robotics •Communication devices • Drones • Consumer robots


Ultrasonic sensors offer the best performance for range finding applications

Power consumption

Up to 500 times lowerpower consumption

Sensitivityto lighting

Range and accuracy not affected by ambient light or sunlight

Detect dark or transparent objects

Sense any color target and windows, mirrors

Range noise Up to 100 times lower noise

Field-of-view (FoV) Up to 5 times wider

Advantages of ultrasonic ToF sensors vs. infrared ToF sensors


The new Chirp ultrasonic ToF sensorSonar on a chip

Main features● Miniature size up to 1000 times smaller

than conventional solutions● Ultra-low power consumption (<15 µW)

up to 100 times lower than conventional solutions

● Measuring range of 1 cm to 500 cm● Very low noise range measurement

of <1 mmRMS

● Wide field-of-view (FoV) up to 180°● Integrated DSP chip for ultrasonic

signal processing ● I2C Interface

Ultrasound engine


MEMS ultrasonic ToF sensor specifications

Features & benefits● Range, proximity, presence

and gesture sensor in one● Low always-on power● High accuracy● Programmable operating range● Fast response time● Wide and customizable FoV

to customer requirements● Insensitive to ambient light

or color of objects

Specification CH-101 CH-201

Dimensions 3.5 mm x 3.5 mm x 1.25 mm

Operating range ≤1.2 m ≤5 m

Voltage 1.8 V

Interface I2C

Power@ 1 sample/s and max. range

12 µA 20 µA

Power @ 30 samples/s and max. range

110 µA 330 µA

Sample rate ≤100/s @ 1 m ≤30/s @ 5 m

FoV ≤180 °

Range noise 1 mmRMS @ 30 cm 0.2 mmRMS @ 1 m


SiP with wide range of programmable functionality

CH-101 and CH-201 are systems in package (SiP) with● Piezoelectric micromachined

ultrasonic transducer (PMUT) and

● Programmable system-on-chip (SoC) for all ultrasonic signal processing

PMUT

Ultrasonic pulse

Programmable firmware for many functionalities,such as range-finding, proximity sensing and presence detection


Easy to interface to microcontrollers

Features● CH-101 and CH-201

sensors feature an I2C interface and operate from a 1.8 V supply

● Multiple sensors can sharethe same I2C bus

● CH-101 and CH-201 are pin-compatible and have the same API

SDA (Master)SCL (Master)GPIOGPIOGPIO

GND

VDDMicrocontroller

SDASCL

PROGINTRESET_N

VSS

VDD

AVDD23

145

6

78CH-201

0.1µF

SDASCL

PROGINTRESET_N

VSS

VDD

AVDD23

145

6

78

0.1µF

2k2

2k2

10k

1.8V

1.8VCH-x01

Platform-independent C driver software helps customerswith embedded software development


CH-201 ultrasonic ToF sensor performance

+

Range and FoV can be optimized with customized housings serving as apertures

45°135°

20004000

60008000

1000012000

14000

0°180°

90°

Range measurement up to 5 m Field of view (FoV) with narrow FoV housing

5000

Ran

ge (m

m)

Target distance (mm)

100 samples at each distance (noise is too small too see)

4000

3000

2000

1000

1000 2000 3000 4000 5000

Range (mm) vs. Stage Distance


CH-201 range and range noise

Noise up to 100x lower than competing IR ToF sensors at 120 cm range

Range noise @120 cm Range noise vs. target range6

Ran

ge n

oise

(mm

)

Range (m)0

5

4

3

2

1

01 2 3 4 5 6

Corner reflector target

Wall target

±0.35 mm 1σ

120.3120.2120.1120.0 120.4 120.5

Target distance (cm)


Solutions from component to system level

Echo from target Transmit burst

Time of flight

• Piezoelectric micromachinedultrasonic transducer (PMUT)

• Ultrasound SoC

• Custom package

• Programmable SoC enables customized sensing

Application-specific software enables• Fast time to market• Design of solutions with

multiple Chirp sensors

On-chip sensing algorithms Complete system solutionsUnique sensor components


6-DoF controller reference design

Cortex-M0MCU

InvenSenseIMU

Chirp CH-101

(1 or more)

Chirp CH-101

(1 or more)

Chirp CH-101

(1 or more)

2.4 GHz RF link

Apps processor

InvenSenseIMU

2.4 GHz RF link

Head-mounted display

Chirp embedded software

Hand-held controller

Features & Benefits● Provides 6-DoF controller

tracking based on sensor fusion● Fuses ultrasonic ToF with IMU

acceleration/rotation rate for low-latency, high accuracy tracking

● Mobile-ready (no base station required)

● Near zero computation load ● Very low power consumption● Works in any lighting condition

Chirp fusion engine

software

Chirp CH-101

(1 or more)

Chirp CH-101

(1 or more)

Chirp CH-101(up to 6)

Ultrasound

www.tdk-electronics.tdk.com

Documents

TPC 18: World’s first MEMS ultrasonic time-of-flight sensors · 2018-11-14 · Provides 6-DoF controller tracking based on sensor fusion Fuses ultrasonic ToF with IMU acceleration/rotation