Magnetorheological (MR) Brake System

1
Magnetorheological (MR) Brake System

• Dr. Khisbullah Hudha

2
Problems with Conventional Hydraulic Brake System

• High energy consumptions
• Bulky
• Problems with leakage in hydraulic line
• Brake noise due to metal-with-metal friction
• Brake pad need to be replaced periodically
• Response delay due to pressure build up
• Require auxiliary components such as hydraulic
  pump, fluid transfer, brake valve fluid
  researvoir)

3
2 Types of Hydraulic Brake System
4
Why Magnetorheological Brake

• Low power requirement (only several ampere)
• Simple design construction
• Hydraulic free no hydraulic line need less
  space requirement
• No metal-with-metal friction
• No brake pad needed
• Easy to control (potential to be used for
  brake-by-wire (BBW) system)
• Fast response (0.02 second)

5
Components of MR Fluid

• Iron Particle micron or nano size
• Carrier fluids synthetic oil, silicone or water
• Binder Material (to prevent the iron particles
  from settling down) special grease

6
Behavior of MR Fluid
7
MR Fluid

• MR fluids are created by adding micron-sized iron
  particles to an appropriate carrier fluid such as
  oil, water or silicon.
• Their rheological behavior is almost the same as
  that of the carrier when no external magnetic
  field is present.
• When exposed to a magnetic field, the iron
  particles acquire a dipole moment aligned with
  the applied magnetic field to form linear chains
  parallel to the field

8
Basic design of MR Brake
9
Prototype of MR Brake developed in Autotronics
Lab - UTeM
10
(No Transcript)
11
MR Brake Test Rig available in Autotronics Lab -
UTeM
12
System Modeling
13
Equations of Motion

• Case 1 Belt tensioner on (Speed Control)
• - Torque of the motor will be transferred to
• the driven shaft via belt-pulley system

Where Tm torque of the motor Ts torque of
the shaft h efficiency of belt-pulley system
(96 - 98)
14
Where b viscous damping of the bearing Tmr
brake torque J load moment of inertia
15
Torque of MR Brake (Tmr)

• MR Fluid behavior
• MR Brake Torque Calculation

16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
Speed control
20
Case 2 Belt Tensioner off (torque control or
stopping time control)
Belt off Ts 0
21
Equations of Motion
Omega dot negatif deceleration
22
(No Transcript)
23
Motor Torque (belt tensioner off at t 4 sec)
24
Current applied starting from t4sec)
25
Stopping time