Introduction to proximity sensor for robotics

1. Overview of proximity sensor
① What is proximity sense
② Examples of proximity sensor and its applications
2. Principle of proximity sensor
① Light reflection method
② Capacitance (electric field) method
③ Triangulation method
④ Time of Flight(TOF) method
⑤ Eddy current method
⑥ Ultrasonic method
3. Examples of the development and application of proximity sensors
① optical type
② capasitance (electric field) type
③ ToF(Time of Flight) type
④ Proximity / Tactile type
4. Summary

1. The University of Electro-Communications Department of Mechanical Engineering and Intelligent System
Introduction to proximity sensor for robotics
“Principle, R & D and Applications”ver.1
Makoto SHIMOJO
Professor Emeritus, University of Electro-Communications
https://researchmap.jp/read0072509/

2. Contents
2
1.Overview of proximity sensor
① What is proximity sense
② Examples of proximity sensor and its applications
2.Principle of proximity sensor
① Light reflection method
② Capacitance (electric field) method
③ Triangulation method
④ Time of Flight(TOF) method
⑤ Eddy current method
⑥ Ultrasonic method
3.Examples of the development and
application of proximity sensors
① optical type
② capacitance (electric field) type
③ ToF(Time of Flight) type
④ Proximity / Tactile type
4.Summary

3. comments
3
This icon is displayed in the case of a sensor
example developed in Shimojo Lab.
This icon indicates a supplementary explanation.
The examples below are just a few of the many proximity sensors that have been developed.
I think that important development examples and usage examples are missing.
The cause is the lack of surveys and lack of knowledge of the author.
Source papers of the example sensors are shown on
each slide.
Showed URL when video (youtube) exists.

4. 1. Overview of proximity sensor
4
1. Overview of
proximity sensor

5. What is proximity sense
5
tactile proximity
Proximity is a spatial extension of
tactile sense.
(Super Tactile)

6. What is proximity sense
6
Photoreflector
Photo-transistor
LED
Non-contact detection
i
EE-SY1200
Emit light and detect
reflected light
Proximity area
Proximity is the spatial
expansion of tactile sense
Light
An example
of sensor

7. Advantages of proximity sensor
7
Tactile sensors
detect contact
Detect after
collision !
Pre-collision-detection is important for safety
But
Collision
avoidance
Object Detection

8. Problems with vision and touch
8
Detect nearby objects
(proximity areas) with
proximity sensor
Enable High-speed operation
Enable Collision avoidance
Enable soft contact
Enable Non-contact interaction
For safety, the operation
should be slow near the
object to avoid collision.
Vision has measurement
errors, occlusion and
blind spots.
Tactilecannot detect until
it touches.
Problems
Solution
Missing information near the object

9. Examples of using proximity sensors
9
Touchless OperationPre-collision
detection
Proximity Servoing
Tracing & approaching
Detection of approaching
surface shape
Surface / Edge / corner etc.
Safe and secure
operation
High-speed
operation
Stable and non-
destructive
operation
Edge tracing
Fast
approaching
Soft
Touching
Non-destructive
operation
High-speed
operation
Stable grasp and
manipulation
Corner
×
〇
× Edge
surface

10. Information from proximity and its applications
10
distance
Collision
avoidance
direction
shape
(distribution)
Soft contact
Proximity
Servoing
High speed /
stable grasp
Type
Types and use of
detected information
Non-contact →
non-destructive
Improve safety
High-speed
operation
Application to
touchless
interface
Dexterous
manipulation
Proximity
sensor
Features
Distance
to object
Surface
direction
Position &
orientation of
the object
Approaching
surface shape
Plane / Edge / Corner
Time to contact
Approaching
speed

11. Position of proximity
11
Vision ProximityTactile
vision tactileproximity
non-contact contact
Proximity connects vision and tactile seamlessly
Wide area
Expectation
Occlusion/
Blind spot
Local area
Confirmation
Not detected
until contact
There is occlusion in vision, and tactile cannot be detected until contact.
In order to avoid collision, the operation should be slow near the object.
Proximity sensor seamlessly connect visual and tactile information to
ensure reliable and high-speed operation.

12. Output example of proximity sensor
12
©shimojo
https://www.youtube.com/watch?v=ILmK0DinkYM
Proximity sensor with photo-reflectors arranged in 16x16 array. The sensor output is
displayed in color. The output pattern changes according to the distance.
ProximitySensor(16×16 array)
Proximity sensor outputProximity sensor output

13. Application example of proximity sensor to robot
13
https://www.youtube.com/watch?v=gaxcQPKM9C8
https://www.youtube.com/watch?v=M0QYP-V7qB8
M. Shimojo, T. Araki, S. Teshigawara, A. Ming, M. Ishikawa, A Net-Structure
Tactile Sensor Covering Free-form Surface and Ensuring High-Speed Response,
Int. Conf. on Intelligent Robots and Systems(IROS 2007), 670-675, 2007
Proximity
sensor
Proximity sensor
Tracking
Proximity sensor
avoiding
Proximity sensor placed at fingertip
One-to-one connection between sensor
outputs and finger drive motors (Reactive
control)
Proximity sensor placed at the end of arm
Tracking with the proximity on the tip top
Avoidance with the proximity on the tip side
K. Koyama, H. Hasegawa, Y. Suzuki, A. Ming, M. Shimojo, Pre-Shaping for Various
Objects by the Robot Hand Equipped with Resistor Network Structure Proximity
Sensor, Int. Conf. on Intelligent Robots and Systems(IROS) 4027-4033,2013
Tracing a fast moving object surface Tracking and avoidance
https://www.youtube.com/watch?v=sCgZdzQL0GQ&t=35shttps://www.youtube.com/watch?v=Bi0o-ai6-yM&feature=emb_logo

14. 2. Principle of proximity sensor
14
2. Principle of
proximity sensor

15. Detection principle of proximity sensor
15
1.Light reflection method
2.Capacitance (electric field) method
3.Triangulation method
4.Optical round trip time (TOF) method
5.Eddy current method
6.Ultrasonic method

16. (1) Light reflection method
16
Since the reflected light intensity changes
according to the distance of the object, the
proximity distance information is detected.
Pros:
Fast response speed
High spatial resolution
Compact, lightweight, inexpensive,
rich in variety
Cons:
Affected by light-reflectance, such
as, surface roughness, and color
of the object.
Affected by disturbance light.
EE-SY1200
3.2mmx1.9mm
Photo reflector characteristics
Distance
Output
Object

17. Light reflection method Ex.1
17
17
①The sensor element is divided into 60
parts in the circumferential direction.
②Detects the direction and distance of
approaching an object within 1ms.
③For several approaching objects, the
direction, distance, and number of the
approaching objects are indicated.
Terada, K.; Suzuki, Y.; Hasegawa, H.; Sone, S.; Ming, A.;
Ishikawa, M.; Shimojo, M.. Development of Omni-directional
and Fast-responsive Net-structure Proximity Sensor, 2011
IEEE/RSJInternational Conference on Intelligent Robots and
Systems (IROS2011) pp. 1954-1961, 2011.
https://www.youtube.com/watch?v=Cfngzj1IFjU
https://www.youtube.com/watch?v=XB3GhOs7UTk
https://www.youtube.com/watch?v=r-n7wJWbeRQ

18. (2)Capacitance (electric field) method
18
①Self-Capacitance Sensing:
Detected from the change in
capacitance due to object
entering the electric field.
②Mutual Capacitance Sensing:
Detected from the
displacement current caused
by object entering electric field.
Pros:
Resistant to stain compared to optical
methods.
Large degree of freedom in shape.
Good for relatively short distances.
A wide area of detection is possible
Cons:
Affected by the shape and material
of the object.
Low spatial resolution.
Low directivity.

19. Explanation of the capacitance method
19
1.The capacitance exists between conductors (metal, human body, etc.).
2.The potential difference between the conductors generates electric field between them.
3.The displacement current flows due to the change in the potential difference between
the conductors.
4.Change the potential difference with an AC osillatorand measure the displacement
current.
5.By detecting changes in displacement current, contact, approach, etc. are detected.
Capacitance
circuit model
Usually less than
several 100 pF
Tobias Grosse-Puppendahl,ChristianHolz,Gabe, Raphael Wimmer, Oskar Bechtold, Steve Hodges, Matthew S Reynolds, Joshua R Smith,"FindingCommon Ground:
A Survey of Capacitive Sensing in Human-Computer Interaction,"Proceedingsof the 2017 CHI Conference on Human Factors in Computing SystemsMay2017 Pages
3293–3315
The capacitance (electric field) method is used for contact, proximity, and
displacement measurement.

20. (3) Triangulation method
20
Measure the distance by triangulation. A
position detecting element such as a PSD
is used as a light receiving element.
Pros:
Not affected by light reflectivity.
Integrated signal processing
circuit.
Variety of types
Cons:
The minimum detection distance
is several centimeters.
Response speed is more than
10 ms(I2C connection).
https://jp.sharp/products/device/lineup/selection/opto/haca/diagram.html
sharp
GP2Y0A710
100〜550cm
GP2Y0A02
20〜150cm
GP2Y0A710
100〜550cm
Model
range
Triangulation
method
Object
Light emitting element

21. (4)Optical round trip time (TOF) method
21
Measure the distance from the
round trip time TOF (Time of Flight)
to the target object.
Pros:
Not affected by light reflectance
such as surface roughness or color.
Integrable, small and lightweight.
Cons:
Measurement accuracy is a few
millimeters
The minimum measurable
distance is 1mm or more.
Fast response?
??????=
�
∆??????
??????=�??????���??????
Δｔ＝round trip time
SPAD(Single-Photon Avalanche Diode)
C: 光速
The frequency f is
L=10mm →Δｔ＝67ｐｓ
Time
difference
Speed of light
laser

22. TOF method ex.1
22
4.8 x 2.8 x 1.0 mm
Communicate
via I2C.
Distance measurement
characteristics
STMicroelectronics Vl6180X
Δtis a statistical value from
multiple trials
→ Trade-off between response
speed and accuracy
STMicroelectronics VL6180X
Range: 0mm(?)-100mm,
Accuracy: about 2-3mm
Response: 15ms (67Hz)
https://www.st.com/content/st_com/en/products/imaging-and-
photonics-solutions/proximity-sensors/vl6180x.html

23. (5) Eddy current method
23
Detects eddy current loss in
electromagnetic induction
The eddy current becomes Joule heat due to the
electrical resistance of the conductor, resulting in
eddy current loss.
Pros:
Available in various
measurement environments.
Such as water or oil.
Available over a wide
temperature range.
Cons:
Limited to conductors such as metal.
The characteristics change
depending on the material.
https://www.keyence.co.jp/ss/products/sensor/sensorbasics/ed_info.jsp
High frequency
magnetic field
Magnetic
flux
Detection
coil
Oscillation
amplitude
Rectified
signal
sensor
far farnear
far
near
Detection
circuit

24. (5) Ultrasonic method
24
Measure the distance from the sound's
round trip time TOF (Time of Flight) to
the object.
Pros:
More resistant to dust and water than
the optical method.
Insensitive to material and color
Transparent object can be detected.
Cons:
Difficult to detect close distance (20mm ~)
High-speed response is difficult (30ms or
more)
Malfunction due to multiple reflections.
??????=
1
2
??????∆????????????:
ＨＣ－ＳＲ０４
Range: 20-4000mm
Response:60ms(max)
Size:45×20×15mm
Δｔ＝round trip time
Sound
speed

25. Proximity sensor detection method and product
25
type Product
Dimensions
[mm]
Response speed
[ms]
Range [mm]
Light
reflection
ROHM RPR-220
OMRON EE-SY1200
4.9 ×6.4 ×6.5
1.9 ×3.2 ×1.1
0.01
0.03
5 ~12
1 ~4
Triangulation
SHARP
GP2Y0E03
GP2AP002S30F
16.7×11.5×5.2
4.0×2.1×1.25
~40.0
~50.0
40~500
25~1450
Time of
Flight（TOF)
STMicroelectronics
VL6180X
VL53L0X
4.8 ×2.8 ×1.0
4.4 ×2.4 ×1.0
7.5~
~20 (Min.)
~100
~2000
Capacitance
(electric
field)
Tactile proximity sensor
OMRON E2K-C25M
40 ×40 ×-
φ34x82
~100.0
(48 elements)
14.3
0 ~100
3～25
Eddy
current
KEYENCEEX-422V φ22×35 0.075(Min.) 0~10
Ultrasonic
SainSmartHC-SR04
OMRONE4C-DS30
45×20×15
φ18x50.2
0.1~23.2
30
20~4000
60ｰ275
Laser
Triangulation
KEYENCEIL-030 48.5×37.9×22.6 0.33(Min.) 20~45

26. Proximity sensor detection method
26
https://doi.org/10.1177/0278364919875811
K. Koyama, M. Shimojo, A. Ming, M. Ishikawa,"Integratedcontrol of a multiple-degree-of-freedom hand and arm using a reactive architecture
based on high-speed proximity sensing,"TheInternational Journal of Robotics Research, 38(14). 1717 -1750, 2019

27. 3. Examples of the development and application of proximity sensors
27
3. Examples of the
development and application
of proximity sensors.
The development examples of proximity sensors have recently increased. In the following, some examples of
sensors mounted on the robot are shown. There are many examples that could not be introduced.

28. Optical type
•Development
example of
optical type
28

29. Autonomous following and grasping (1)
29
Structure of a high-speed proximity sensor
(An example m ×n matrix of detectors where m = 3 and n = 3)
proximity sensor
The proximity sensor at each fingertip has a resistance
network matrix configuration. (Analog circuit)
The sensor detects a value related to the distance to the
object and the center position at high speed (<1 ms).
Using Reactive control based on the sensor output, the
fingers are made to follow the object shape. At the same
time, the position and posture of the arm are controlled to
a right position.
Since the position and posture are controlled in a non-
contact manner, there is no danger of damaging the object
or the robot.
Integrated control of Hand and Arm using
Reactive control based on high-speed
proximity sensing
K. Koyama, M. Shimojo, A. Ming, M. Ishikawa,"Integratedcontrol of a multiple-degree-of-
freedom hand and arm using a reactive architecture based on high-speed proximity sensing,"The
International Journal of Robotics Research, 38(14). 1717 -1750, 201
Analog
circuit

30. Autonomous following and grasping (2)
30
https://www.youtube.com/watch?time_conti
nue=3&v=gaxcQPKM9C8&feature=emb_logo
https://www.youtube.com/watc
h?v=tHsrXsEreCY
Proximity sensor output
Control to make the
fingertip and the
object surface parallel.
Control to grasp the
object at the center
of the finger.
Multi-Degree-of-Freedom Hand and Arm Control Based
on Proximity Output
https://doi.org/10.1177/0278364919875811
Reactive control by one-
to-one connection
between proximity sensor
outputs and joint motors

31. Object detection and grasp by proximity array
31
•Sha Ye, Kenji Suzuki, Yosuke Suzuki, Masatoshi Ishikawa, Makoto
Shimojo: Robust Robotic Grasping Using IR Net-Structure Proximity
Sensor to Handle Objects with Unknown Position and Attitude,2013
IEEE International Conference on Robotics and Automation (ICRA),
pp.3271-3278, Karlsruhe, 2013.5
Proximity sensor is mounted on
palm (5x6) and fingertips.
The proximity sensor array
detects blocks on the table. Then
Grasping and positioning are
performed using the proximity of
the fingertips.
No visual sensors are used.
https://www.youtube.com/watch?v=ef3yN1m_lCk
指先に
配置
proximity sensor array
proximity
sensor

32. Measurement of distance distribution
32
The center position is detected using a photoreflector
connected by a resistor network.
The distance pattern measures the current flowing
through each photo reflector.
The sampling rate is 1 kHz for the detection of the
center position and 100 Hz for the distance pattern.
The figure on the left shows an example of distance
pattern measurement for a sphere and a cylinder.
Photo-reflectors are arranged in an array,
and the distance to the object surface and
the distance pattern are measured.
Y. Hirai, Y. Suzuki, T. Tsuji and T. Watanabe: High-speed and Intelligent Pre-grasp Motion by a Robotic Hand Equipped with Hierarchical Proximity Sensors, IEEE/RSJ
Int. Conf. on Intelligent Robots and Systems, pp.7424-7431, 2018.

33. Tactile Proximity Combined with Compound Eye Camera
33
Compound-eye
camera (9units)
Insert filter
Upper:
Visible light cut
Middle and lower:
Infrared light cut
hand
Tactile: The diffused light from the optical
waveguide plate (Acrylic) is detected by an
infrared camera, and the contact is detected.
Proximity: The transmitted light from the
optical waveguide plate is detected by two
cameras, and the distance is measured from
the parallax.
K. Shimonomura, H. Nakashima and K. Nozu,
"Robotic grasp control with high-resolution combined
tactile and proximity sensing," 2016 IEEE
International Conference on Robotics and Automation
(ICRA), 2016, pp. 138-143.
Tactile
sensor
output
Proximity
sensor
output

34. Object detection by blocking light
34
Di Guo, P. Lancaster, L. Jiang, FuchunSun and J. R. Smith, "Transmissive optical
pretouchsensing for robotic grasping," 2015 IEEE/RSJ International Conference on
Intelligent Robots and Systems (IROS), pp. 5891-5897.
Tissue grasping
1.Kinect:Preliminary
work
point cloud
2.Trace the edge
3.Find the corner
4.Grasp it
Object detection by blocking infrared light.
Four beams of
IR light
Kinect pre-processing and light-blocking detection.
Center detection
1.Gripper rotates around
the x-axisfor180 degrees
2.Records the sensing
information
Detect corners with edge
tracking
Rotate hand
to detect
object center
position

35. Predict contact in cooperative space
35
G. BuizzaAvanzini, N. M. Ceriani, A. M. Zanchettin, P. Rocco and L. Bascetta, "Safety Control of Industrial Robots Based on a Distributed Distance Sensor," inIEEE
Transactions on Control Systems Technology, vol. 22, no. 6, pp. 2127-2140, Nov. 2014.
In order to predict the contact between
a human and a robot in a cooperative
operation space, the optimal position
and number of proximity sensors are
evaluated by simulation.
The on-board sensor method has
advantages of easy development and
calibration, and superior occlusion
elimination.
As a result of the optimization method for
an industrial robot (ABB IRB140), almost
90% of the detection probability is
guaranteed when 20 sensors are used.
As a robot avoidance control, they
propose a reactive control that performs
an avoidance action to enhance safety
based on sensors information.
GP2Y0A02YK
(Sharp )
20-150cm

36. Capacitance (electric field) type
•Example of
capacitance
(electric
field) type
36

37. Left Receive
Right Receive
Short Range
Transmit
Mid-Range
Transmit
Electric Field PretouchSystem
37
Finger electrodes attached to bottom of sensor board.
Difference in
sensor output
(relative ratio)
The approaching object is detected from the
change in the electric field. An object is
detected by a sensor at the fingertip of the
hand, and the object is grasped.
https://www.youtube.com/watch?v=tMk0WKjqrk0
Mid-rangeshort-range
B. Mayton, L. LeGrand, and J.R. Smith,"AnElectric Field PretouchSystem for
Grasping and Co-Manipulation," 2010 IEEE Int. Conf. on Robotics and Automation

38. Robot Collision Avoidance
38
transmitter
receiver
displacement
current
https://www.youtube.com/watch?v=v7C_SHweCxM
T. Schlegl, T. Kröger, A. Gaschler, O. Khatib, H. Zangl,"Virtual Whiskers —Highly
Responsive Robot Collision Avoidance," 2013 IEEE/RSJ Int. Conf. on Intelligent
Robots and Systems
displacement
current

39. Proximity servoing for preshaping and haptic exploration
39
Force mode: Measured by the capacitance
between Layer A and B.
Proximity mode: Measured by the capacitance
between Layer B and the contact object.
裏
Measures the position and orientation
of an object using proximity sensors
on both sides of the hand
Proximity servoingfor preshaping
https://www.youtube.com/watch?v=nwH9GfzTek8
S.E. Navarro, M. Schonert, B. Hein, H. Wörn,"6D proximity servoing for preshaping
and haptic exploration using capacitive tactile proximity sensors,"2014 IEEE/RSJ
International Conference on Intelligent Robots and Systems

40. Measure the characteristics inside the object during operation
40
https://www.youtube.com/watch?v=htc3lj8Los0&feature=youtu.be
S. Mühlbacher-Karrer, A. Gaschlerand H. Zangl, "Responsive fingers —capacitive sensing
during object manipulation,"2015 IEEE/RSJ International Conference on Intelligent Robots
and Systems (IROS), Hamburg, 2015, pp. 4394-4401.
Capacitance sensing: Switch the
excitation mode of the electrodes
and measure the characteristics
inside the object during operation.
Detected based on the difference
between single-ended measurement
(capacity between electrode and
ground) and differential measurement
(capacity between electrodes).
Classify empty and non-empty bottles.
S1: Measure mode switching
Simulation of electric field change by object
Electrodes

41. ToF(Time of Flight) type
•Development
example of
ToFtype
41

42. Capacitive Proximity Sensor for Material Detection
42
VL53L0X
1.ToF:
Medium distance
2.Capacitive type:
Proximity distance
Non-contact material
discrimination
Material identification: Impedance
measurement
Y. Ding, H. Zhang and U. Thomas, "Capacitive Proximity Sensor Skin for Contactless Material Detection,"2018 IEEE/RSJ International Conference on Intelligent
Robots and Systems (IROS), Madrid, 2018, pp. 7179-7184.
Example of impedance
measurement
Real part
Imaginary part
Cooling Pad, Coated Steel, ESD Foam
(Antistatic agent), Pork and Human
from 0.2mm distance
Solid line: real part
dotted line: imaginary part

43. Proximity and Contact Sensor for Human Cooperative Robot
43
27x27mm/
cell
Sensor configuration
ToF(VL6180X) +
capacitance type module
24 modules connected
via I2C
Total measurement
speed is 58ms
(measurement +
transmission)
ToF: VL6180X
Enlarge
capacitance
Measurement results
Object (100 ×100mm): Paste white and
black paper on conductor and Acrylic.
Combination
Long distance: ToF
Short distance:
capacitance type
S. Tsuji and T. Kohama, “Proximity and Contact Sensor for Human Cooperative Robot by Combining Time-of-Flight and Self-Capacitance Sensors,” in IEEE
Sensors Journal, 2020.
Enlarge

44. Proximity Servoingtowards Safe Human-Robot-Interaction44
As a collision avoidance path, They propose a
proximity servo method that moves around
obstacles.
The avoidance motion maintains the task
motion as long as the collision avoidance
motion allows.
Compared to a 3D depth camera, most of the
workspace area can be covered with a minimum
number of measurement points.
The narrow field of view of the ToFsensing is
covered by the combination with the wide area
capacitive sensing.
Manipulator equipped with multimodal
proximity sensing modules distributed
on the robot’s surface
front back
capacitive
electrodes
TOF
RGB
LED
Proximity module: Combination of
capacitance and ToFsensor.
The robot performs collision avoidance
by reflex motion control in a changing
environment.
Y. Ding, F. Wilhelm, L. Faulhammer, and U. Thomas, “With proximityservoingtowards safe human-robot-interaction,” in 2019 IEEE/RSJ International
Conference on Intelligent Robots and Systems (IROS). IEEE, 2019, pp. 4907–4912.
Proximity sensor cuff (PSC)
12 elements/PSC
Proximity sensing cuffs allow the
robot to perform avoidance motions

45. Detecting both Target Object and Support Surface
45
K. Sasaki, K. Koyama, A. Ming, M. Shimojo, R. Plateauxand J. Choley, "Robotic Grasping Using Proximity Sensors for Detecting both Target Object and Support
Surface,"2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Madrid, 2018, pp. 2925-2932.
fingernail
ToF(VL6180X)
PhotRef( SY1200)
By the sensor, the hand can
approach the object and support
surface coarsely first, and then
can be controlled fast and
precisely to realize adequate
grasping motion.
Proximity sensor
Fingertip:
A photoreflectorcomposed of a
resistor network. Detects center
position and distance.
Fingernail:
Photo reflector. Measure
position and orientation with
object
ToF: Measures distance to
support surface regardless of
reflectance
Grasping a thin object using proximity sensors. Fingertip sensors are used for
detecting target object and finger nail sensors are used for detecting support surface

46. Visionless Tele-Exploration
46
VL6180X
Total 6 pieces
Interactionwithtargetsispossiblewithoutthenegative
consequencesofrobotcontactwithunknownobject.
Doesnotcausedamageorunwanteddisplacementofthe
target.
Theoperatorcanconcentratemoreactivelyonsearching.
Hapticfeedbackhaslessthanhalfthecollisioncomparedto
non-hapticfeedback.Usersconsistentlyapproachedthe
objectofinterest.
Benefits: Exploring dynamic objects and areas that
cannot be adequately viewed with due to space
constraints, accessibility, or occlusion
①Guidance force
②Fobiddenarea
force
③Proximity move
K. Huang, P. Lancaster, J. R. Smith and H. J. Chizeck, "Visionless Tele-Exploration of 3D Moving
Objects,"2018 IEEE International Conference on Robotics and Biomimetics (ROBIO), Kuala
Lumpur, Malaysia, 2018, pp. 2238-2244.
①
②
③

47. Proximity / Tactile type
•Development
example of
Proximity /
Tactile type
47

48. HEX-O-SKIN(1)(Force, proximity, temperature, acceleration)
48
Force, proximity, temperature, acceleration sensor
combined sensor (hexagonal structure)
Characteristic:
The hexagon is connected to an adjacent hexagon
at the port and transmits measurement
data.
Proximity (GP2S60), acceleration (BMA150),
temperature (PCS1.132), capacitive
force sensor (MEMS).
Low flexibility.
GP2S60
sharp
HEX-O-SKIN
Philipp Mittendorfer, Gordon Cheng,Integrating Discrete Force Cells into Multi-modal Artificial
Skin,Humanoid Robots (Humanoids), 2012 12th IEEE-RAS International Conference on

49. HEX-O-SKIN(2)(Force, proximity, temperature, acceleration)
4949
https://www.youtube.com/watch?v=M-Y2HW6JcGI
G. Cheng, E. Dean-Leon, F. Bergner, J. Rogelio
GuadarramaOlvera, Q. Leboutetand P. Mittendorfer,
"A Comprehensive Realization of Robot Skin: Sensors,
Sensing, Control, and Applications," inProceedings of
the IEEE, vol. 107, no. 10, pp. 2034-2051, Oct. 2019.

50. Dual-Mode Capacitive Proximity Sensor
50
HK Lee, SI Chang, E Yoon, Dual-Mode Capacitive Proximity Sensor for Robot Application: Implementation of Tactile and Proximity Sensing Capability on a Single
Polymer Platform Using Shared Electrodes, IEEE Sensors Journal, 9,12, 1748 -1755, 2009
Capacitive tactile / proximity sensor with 16 ×16
electrode matrix formed on PDMS
(Polydimethylsiloxane).
Tactile sensing by change of capacitance due to
deformation of contact force.
Proximity sensing by electrostatic coupling
generated between electrode and object.
The detector is 22mm square.
Proximity
mode
Tactile
mode

51. Tactile / proximity sensor is arranged all around the finger
51
Tactile proximity sensor configuration:
Embed the reflector-type proximity
sensor in silicone rubber,
Proximity: Reflected light from the
object + rubber surface reflection (B)
Contact: Increase in rubber surface
reflection (A)
A B
Reflector-type
proximity
Top: 4
pieces
4 sides: 8
pieces
36 in total
Take out the object from the bag
Detects objects around the
finger,
Avoid objects,
Follow the object surface,
To detect edges, etc.
can be executed.
内部
N. Yamaguchi, S. Hasegawa, K. Okada and M. Inaba, "A Gripper for Object Search and Grasp Through Proximity Sensing,"2018 IEEE/RSJ International Conference
on Intelligent Robots and Systems (IROS), Madrid, 2018, pp. 1-9.

52. Tactile / proximity sensor
52
VNCL40101
proximity sensors
PDMS
VNCL40101: proximity sensor
detecting objects a distance up to 20 cm.
reliable detection: atdistanceup to 6–7 cm
1.Proximity: The approach of the
object is detected from the
reflected light intensity.
2.Force: Force is estimated by
detecting the amount of PDMS
deformation after contact from the
reflected light intensity.
Dana Hughes, John Lammie,andNikolaus Correll, A Robotic Skin for
Collision Avoidance and Affective Touch Recognition, IEEE ROBOTICS
AND AUTOMATION LETTERS, VOL.3, NO.3, pp.1386-1393, 2018
Photoreflectors(VNCL40101) are arranged
below the highly transparent PDMS layer.

53. Proximity sensor with high accuracy and fast response(1)
53
It is not affected by the reflectance of the object
surface. This is due to the arrangement of the
photo reflector and its flashing phase.
Response time: 1 ms, accuracy: 50 mm.
High sensitivity contact detection is possible by
regarding the distance to the target as zero.
The contact force can be measured by
measuring the displacement of the flexible
fingertip after contact.
Koyama, K; Shimojo, M; Senoo, T; Ishikawa, M: High-Speed High-Precision Proximity Sensor for Detection of Tilt, Distance, and Contact, Koyama, IEEE Robotics
and Automation Letters 3(4) pp.3224-3231, 2018.
The distance and inclination to the object surface
are measuredat high speed and high accuracy
without being affected by the light reflectance.
1) proximity
2) tactile
elastomer
LEDs
Phot.Diode
elastomer

54. Proximity sensor with high accuracy and fast response(2)
54
Distance mode
https://www.youtube.com/watch?v=v0jTcjZWz88
https://www.youtube.com/watch?v=UVMg2qdhdYs

55. 4. Proximity Summary
55
4. Proximity
Summary

56. What is the sense of proximity
56
Extend the tactile sense spatially by
several tens of cm (Super Tactile).
New control / operation method using
pre-contact information.
What is the sense of proximity
Spatial expansion: proximity sense
Temporal expansion: Fast and slow /time shift
processing
Modality expansion : Interconversion and
presentation between different senses

57. Proximity Summary 1
57
The following are the problems of the conventional tactile sensor.
1.Information cannot be obtained without contact. Therefore, the
approaching is performed at a low speed so as not to collide with the
target object.Also when contact is lost during manipulation, control
becomes difficult.
2.The tactile sensor needs to have physical durability against bend and
stretch, rubbing, and impact, and chemical resistance against water,
oil, and chemical substances.
3.When the flexibility of the sensor is low, uniform contact is difficult. As
a result, the contact becomes uneven, making it difficult to obtain
information on the entire surface.
4.Tracing is difficult. It is difficult to control the tracking motion while
maintaining contact with the object.
5.To cover the surface, it is necessary to arrange a large number of
detection elements, and the wiring becomes difficult. (Proximity is
possible with a small number.).

58. Proximity Summary 2
58
1.Tactile is used for measurements, force and stiffness that really
require contact. Recognition of shapes, edge detection, etc. are left
to visual or proximity that can be measured without contact.
2.Tactile cannot be detected when contact is lost. The control becomes
extremely difficult if there is no contact during the grasping operation.
This is a major drawback in manipulation, and in this regard, it is
more reasonable to use the proximity, which allows continuous
measurement even if the contact is broken.
3.For these reasons, proximity servoingis considered better than
tactile servoing.
4.In the future, the development of the proximity with the contact force
detection function and the application to the proximity servoingcan
be expected.
Thus,mostofthedifficultyintactileisrelatedtocontact.Sowhatisthe
realneedforcontact?

59. Summary of robot hand by proximity sensor control
59
1.When the hand approaches the object, it automatically follows the
shape of the object and grasps it .
2.Enables high-speed grasping operation.
3.Since control is possible with one software for grasping, software for
each object is not required.
4.No vision needed. Or a very simple vision (kinect, etc.) is sufficient.
5.Autonomous following and grasping. Even if the object moves, it can
be grasped.
The control method using the proximity sensor complements the information
loss due to visual occlusion, and can detect a few centimeters before the
contact reliably, so that high-speed control is possible.
The robot hand by the proximity sensor control method has the
following advantages.
https://doi.org/10.1177/0278364919875811

60. end
60

61. Distribution measurement by proximity sensor array
61
Infrared LED sensors arranged in
an array on a strip-shaped
flexible printed circuit board
Detection range: 0 to 300mm
Responsivity: 500Hz
Interface: CAN
(NSK Ltd.)
https://www.nsk.com/jp/company/news/2015/press1201b.html

62. Gesture sensor using proximity
62
Gesture sensor that detects hand
movements away from the screen
Detecting the direction of hand
movement by holding your hand over
the sensor on a touch panel
Sharp Ltd.
http://www.sharp.co.jp/corporate/rd/n38/pdf/201310topics2.pdf