トルクセンサー開発計画

Confidential
Presentation of
Torque Sensor(TQ3)
This is a presentation of a newly developed Torque Sensor
for an electric power-assisted bicycle.
March,2012
Mr. M..Baba / BM-Technology
Configuration of Electric Power-assisted Bicycle
Electric Power-assisted Bicycle
Battery-assisted bicycles are a bicycle and
the interim vehicles of a motorcycle, detect
power, number of rotations, etc. which step
on a pedal by a sensor, and assist the
power to step on by the carried motor.
Although the right figure is one example
of a commercial electric assistant bicycle, it
mainly consists of the following units.
Hand Controller
Battery
Main Control Unit
1.Body
2.Main Control Unit
3.Battery
4.Torque Sensor
5.Motor
6.Hand controller
•
Body
Torque Sensor
It is a sensor unit which detects the
power which steps on a pedal, and
outputs the important signal used as the
basis of motor drive control.
Since there is no general-purpose sensor
marketed, each assistant bicycle maker
developed uniquely and has included in the
in-house product.
2015/10/1
Torque Sensor
BMT
Motor
2
Torque Sensor Development Schedule
2011.12.21
@BMT
The main features
•
•
Radio, a thin shape
Distortion detection
system
L
e
v
e
l
4G
Step3
TQ4
3G
Step2
•
•
TQ3
Starting torque detection
Movement detection
system
•
Cheapness, a thin
shape
Phase difference
detection system
@2,000
2G
TQ2
Step1
•
@3,000
Target price
@1,500
OEM
BASIC
TQ1
TQ1xx
@1,000
Time
2015/10/1
BMT
3
Technical-specifications outline
Model : TQ-3/TQ-3R
Item
2015/10/1
TQ-3/TQ-3R*
Load detecting scheme
Movement detection
Detection principle
The relative distance between a
load side and the non-load side is
proportional to load.
Load signal output
Digital Data
Start-up load detection
yes
Number-of-rotations detection
yes*
Direction of Rotation
Received Data
Output cable
No cable (Radio)
Built-in electric circuit
CPU inside
Power supply for operation
Battery(3V)
Body attachment and wiring
No needed
Cost
Not expensive
BMT
4
Appearance of torque sensor TQ-3
Surface
Number of teeth: 38
Crank length: 170 mm
Back
2015/10/1
BMT
5
The comparison table of an another type torque sensor and TQ3
Detection
principle
Maker
Feature
Magnetost
riction
Panasoni
c
A twist of the metal bar by load is detected by
non-contact by a magnetostrictive element.
-The accuracy of a detection gap is required.
vertical
migration
Sanyo
Movement of the direction of rotation by load is
changed perpendicularly, and change of the
amount of inductance is detected by noncontact.
- Thickness is needed for vertical migration.
Body
Cost
Difficulty
Processing
accuracy
High
High
High
Low
Low
Mid.
Exclusi
ve use
Rotation
gap
Yamaha
Two gear rotation differences by load are
detected by non-contact.
- Structures are complexity, a motor, and solid
construction.
High
High
High
Rotational
transfer
BMT
(TQ3)
(TQ3R)
The movement of the direction of rotation is
detected by non-contact.
- Structure is easy and can make low-cost. .
-Fixed needlessness , Wiring needlessness
- By kit-izing with required parts, production of
an assistant bicycle is simply possible.
Mid.
High
Mid.
2015/10/1
BMT
Wide
use
6
The feature of torque sensor TQ-3
•
Feature
1.
For [ general-purpose ] the bodies
•Product specification (reference)
The body for exclusive use is unnecessary and it can
apply it to the usual bicycle frame easily.
2.
3.
4.
5.
6.
Item
Thin form
Since product thickness is thin, various bicycle
frames are suited. Moreover, it can respond
also to dedicating in a chain cover.
Attachment is easy.
Attachment can be simply done for the body.
Since it is radio system, there is no necessity
for wiring.
Number-of-rotations output (only TQ3R *)
Spec.
1
Load range
0 ‐ 65kgf (170mm)
2
Maximum pedal load
150kgf (170mm)
3
Output data
Load,Rotation,Vbattery
Operating time,etc
4
RF
ISM(2.4GHz) DSSS
5
Transmission distance
2m
The number of rotations of a crank can be outputted (6
p/r). An output becomes a digital data.
6
Transmission cycle
100 ms
Load proportionality output
7
Transmission form
Hex. Data
Wireless transfer of the torque numerical value by the
linear output proportional to the power which steps on a
pedal is carried out.
8
Battery
CR3032
9
Outside dimension
160Φx21H
Weight
800g (a crank is not
included)
Easy structure
10
Component parts were reduced according to an easy
structure, and low cost was realized.
2015/10/1
BMT
7