Transcript Slide 1

ECE5320 Mechatronics
Assignment#01: Literature Survey on Sensors and Actuators
Inductive Proximity Sensors
Prepared by:
Amin Hernandez
Dept. of Electrical and Computer
Engineering
Utah State University
T: (435)797-; F: (435)797-3054 (ECE Dept.)
[email protected]
Outline
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Reference List
To Explore Further
Major Applications
Basic Working Principle
Sensor Selection
Major Specifications
Limitations
Mounting Restrictions
Purchasing Information
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Reference List
http://www.pc-control.co.uk/Inductive.htm
Suffi, Guerrino; “Inductive Proximity Sensors: Design, Selection,
Specification and Implementation”: Proximity Sensor Product Marketing,
Omron Electronics LLC
Suffi, Guerrino; “Old School Proximity Sensor Implementation”: Proximity
Sensor Product Marketing, Omron Electronics LLC
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
To Explore Further
 To see more information concerning applications, and technical
information should visit BALLUFF: sensors worldwide
(http://www.balluff.com/Balluff/us/ProductsChannel/Overview/en/Inductive+Proximity+Sensors.htm)
 To see purchasing information and pricing should visit AUTOMATIONDIRECT
http://web1.automationdirect.com/adc/Technical/Catalog/Sensors_-z-_Encoders/Inductive_Proximity_Sensors
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Major Applications
 Automation
 Industrial
Processes
Processes
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal
 Inductive proximity sensors operate
under the electrical principle of inductance.
 Inductance is the phenomenon where a
fluctuating current, which by definition has
a magnetic component, induces an
electromotive force (emf) in a target object.
In circuit design, one measures this
inductance in H (henrys).
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal
An inductive proximity sensor has four components:
 Coil
 Oscillator
Detection circuit
Output circuit
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal
 When a metal object moves into the inductive proximity
sensor’s field of detection, Eddy circuits build up in the
metallic object, magnetically push back, and finally dampen
the Inductive sensor’s own oscillation field.
 The sensor’s detection circuit monitors the oscillator’s
strength and triggers an output from the output circuitry
when the oscillator becomes dampened to a sufficient level.
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal
Inductive proximity sensors come in two forms:
 shielded
It can be embedded flush in its mounting material without
affecting the sensor’s field of detection
 unshielded
It has the advantage of longer sensing distances, but the disadvantage
of not being embeddable.
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Sensor Selection
Inductive proximity sensors categorize in five specific types:
 Cylindrical
 Rectangular
 Miniature
 Harsh environment
 Special purpose
http://www.balluff.com/Balluff/us/ProductsChannel/Overview/en/Inductive+Proximity+Sensors.htm
Note: 70% of all inductive proximity sensor purchases are of the standardized cylindrical
threaded barrel type.
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Major Specifications
 Sensing Distance
 Reset Distance
 Setting Distance
 Standard Detectable Object
Connection Options
Housing Construction
Housing Style
Cable Type and Length
Features
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Major Specifications
Standard Detectable Object
 When an inductive proximity sensor’s data sheet refers to a
standard detectable object, it tells the specified shape, size, and
material which is used as the standard to examine the performance
of the proximity sensor.
 This understanding is important because the detection distance
of the inductive proximity sensor differs according to the shape
and material of an object. Typically, the standard detectable object
will be an iron plate with a thickness of 1mm and height and
width of equal length to the diameter of the inductive sensor.
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Major Specifications
Detection Distance
 Detection distance is the position at which the inductive proximity
sensor operates when a “standard detectable object” is moved in front of
the sensor in a defined manner. For an Inductive proximity sensor with an
end (or “front”) detection surface, the detection distance is determined by
aligning the center line of the Inductive sensor with the center line of the
standard detectable object.
 The standard detectable object is moved towards the face of the
inductive proximity sensor until the proximity sensor changes states and
the detection distance is determined.
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Major Specifications
Reset Distance
 The reset distance refers to the distance at which the inductive
proximity sensor releases its output when the standard detectable object is
removed from its field of detection. The difference in distance between the
detection distance and the reset distance is called the “Distance
differential.” Typically, the distance differential is from 3% to 10% of the
overall detection distance.
 The distance differential is incorporated into the design of the inductive
proximity sensor to prevent the proximity sensor from having its output
chatter due to noisy environments or detectable object vibrations.
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Major Specifications
 Inductive proximity sensors typically
include their silicon amplifiers and detection
circuitry inside the sensor head housing.
 Normal operating temperatures for silicon
based circuitry is within the realm of -25 to
70C (-13 to 158F).
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Major Specifications
 Inductive proximity sensors come in a wide
variety of body types.
 Rectangular style inductive proximity sensors
range from the sub-miniature (5.5mm X 5.5mm X
19mm) to the flat pack style (25mm X 10mm X
50mm) all the way up to the limit switch housing
size (40mm X 40mm X 115mm).
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Limitations
Influence of surrounding metals
When an inductive proximity sensor is mounted into its
sensing position, it is important to consider the effects of the
mounting hardware itself and other metallic objects that may be
present in the area of the sensor.
For the shielded type of inductive proximity sensor, the
device can be embedded into a metallic mounting fixture up to the
point when the sensor’s face is at an equivalent height as the
mounting surface.
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Limitations
 Alternated frequency types
Alternate frequency inductive sensors oscillate their
magnetic coils at different cycle rates that their standard
inductive proximity sensor counterparts.
 Mutual interference
When multiple inductive proximity sensors are
mounted in close proximity to one another either along side or
in an opposing directions to another inductive proximity sensor,
either inductive sensor can be subject to an effect called mutual
interference.
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Mounting Restrictions
 When it comes to miniaturization, few components so
strongly represent the micro-electronic revolution that has
occurred within the last 10 years as inductive proximity sensors.
Today, the world’s leading manufacturer of inductive proximity
sensors can manufacture a 5.5mm X 5.5mm X 19mm
rectangular proximity sensor with an extended sensing range of
1.6mm.
 Mounting requirements must be considered when
implementing the inductive proximity sensor into your design
otherwise you may encounter reduced sensing distance, false
triggering, or non-detection of the target.
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Purchasing Information
Selection of Inductive Proximity Sensors prices from AutomationDirect
 Popular DC models (8, 12, 18 and 30 mm) great all-around sensors start at $25.00 (AK1-AN-4A)
 Short body round (8, 12 mm) for very tight space applications starting at $30.00 (AM6-AN-4A)
 Analog output (8, 12, 18 and 30 mm) DC with analog output start at $91.75 (AM9-05-1A)
 AC powered (12, 18, and 30 mm) using AC field power start at $31.00 (VK1-A0-1B)
 Stainless steel DC triple sensing (8, 12, 18, and 30 mm) starting at $82.50 (PMW-AN-5A)
 Stainless steel DC (12 mm and 18 mm) - submersible protection starting at $38.00 (PMW-0N-1H)
 Rectangular - compact sizes for angular spaces starting at $16.00 (APS4-12S-E-D)
 Miniature (3, 4, 5 mm) for tight spaces and close-in sensing start at $35.00 (PD1-AN-1A)
http://web3.automationdirect.com/adc/Overview/Catalog/Sensors_-z_Encoders/Inductive_Proximity_Sensors?source=google&keyword=inductive%20proximity%20sensor&type=search&gclid=CK79hJWUjZkCFQ9Jagodmlefcw
ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators