Difference between revisions of "RC08Brushless"

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In 2008 RoboCup switched to brushless DC motors. While brushless motors are smaller and far more efficient than brushed motors the commutation normally performed inside a brushed DC motor will need to be done externally using some control circuitry. There are two main parts to our brushless motor controller solution; the controller which uses sensors on the motor to gate signals to one of three coils, and the half-bridge motor drivers which actually drive the coils.For the controller a special-purpose brushless motor driver IC was used. For information on the motors or motor control software please see their respective pages.
 
In 2008 RoboCup switched to brushless DC motors. While brushless motors are smaller and far more efficient than brushed motors the commutation normally performed inside a brushed DC motor will need to be done externally using some control circuitry. There are two main parts to our brushless motor controller solution; the controller which uses sensors on the motor to gate signals to one of three coils, and the half-bridge motor drivers which actually drive the coils.For the controller a special-purpose brushless motor driver IC was used. For information on the motors or motor control software please see their respective pages.
−
 
−
==Motor Frequency Analysis==
 
  
 
==Tasks==
 
==Tasks==
 
*[ ] Get the motor and begin playing with it
 
*[ ] Get the motor and begin playing with it
−
**[X] Call Maxon and get a recommendation on motor drivers (They spec parts not sure which drivers they use)
+
**[X] Call Maxon and get a recommendation on motor drivers (Note: Already have design for motor drivers)
 
**[X] Figure out max current draw. (10A starting current)
 
**[X] Figure out max current draw. (10A starting current)
−
**[ ] Develope Model of Motor and get Frequency Response
+
**[X] Develop Model of Motor and get Frequency Response (Note: This is a task to be covered in firmware)
−
**[ ] Find and purchase Flat Flex Cable (FFC) connectors
+
**[X] Find and purchase Flat Flex Cable (FFC) connectors (Note: Found one)
−
**[ ] Purchase large mosfets for testing
+
**[X] Purchase large mosfets for testing (Note: Test rig built and verified with drive motors)
−
**[ ] Purchase Surfboard for mounting DSC
+
**[X] Purchase Surfboard for mounting DSC
−
**[ ] Build test rig
+
**[X] Build test rig
−
*[ ] Finalize on a DSC
+
*[X] Finalize on a DSC (Note: No DSC this year. Doing it in logic)
−
*[ ] Choose MOSFETS
+
*[X] Choose MOSFETS
−
*[ ] Sample all the parts
+
*[X] Sample all the parts
−
*[ ] Schematic Design
+
*[X] Schematic Design
 
*[ ] Build prototype
 
*[ ] Build prototype
 
*[ ] Prototype evaluation
 
*[ ] Prototype evaluation
 +
**[ ] Verify current draw under load especially start-up
 +
**[ ] Check if there is any temp rise in FETs in continuous operation
 
*[ ] Make necessary changes
 
*[ ] Make necessary changes
  
 
==Specifications==
 
==Specifications==
 
====Motor Controller Chip====
 
====Motor Controller Chip====
−
* The motor is spec'd at 12V and is 30W
+
* '''Using an FPGA instead of a DSC'''
−
* A decent transient response (dead-time + switching time)
 
−
* 3-Channels in one package
 
−
* Braking is not a requirement but would be nice
 
−
* High Impedance OFF state
 
−
* Fault protection (overvoltage, overcurrent, fast response)
 
−
* Small package
 
−
* Ability to operate in the >20kHz range
 
−
* Gate drive capability (either can directly driver the gate or is open drain.)
 
−
* Data sheet recommends a MOSFET
 
 
* [[RC08BLDCMotorDrivers | Matrix of Potential Drivers]]
 
* [[RC08BLDCMotorDrivers | Matrix of Potential Drivers]]
  
 
====MOSFET====
 
====MOSFET====
 +
* '''See below for the parts to be used this year'''
 
* NMOS and a PMOS  
 
* NMOS and a PMOS  
−
* The FETS have to be able to handle 10A drain current
+
* The FETS have to be able to handle 10A on current
−
* [[RC08MotorFETS | Matrix of Potential FETS]] Other FETs we considered
+
* [[RC08MotorFETS | Matrix of Potential FETS]]
  
 
==Schematics==
 
==Schematics==
−
Schematics
+
<gallery>
 +
Image:RC_mot_drvr_08.jpg|Brushless Motor Driver Schematic
 +
</gallery>
 +
 
 
==Parts==
 
==Parts==
 
We are performing commutation on the FPGA with gate drivers.  
 
We are performing commutation on the FPGA with gate drivers.  
Line 89: Line 84:
 
===Motor Connector===
 
===Motor Connector===
 
Hirose FH12-11S-1SH 11 position 1 mm pitch
 
Hirose FH12-11S-1SH 11 position 1 mm pitch
 +
 +
===Commutation===
 +
CW (looking along the shaft toward the motor)
 +
{| {{table}}
 +
| align="center" style="background:#f0f0f0;"|'''HS 1'''
 +
| align="center" style="background:#f0f0f0;"|'''HS 2'''
 +
| align="center" style="background:#f0f0f0;"|'''HS 3'''
 +
| align="center" style="background:#f0f0f0;"|'''Winding 1'''
 +
| align="center" style="background:#f0f0f0;"|'''Winding 2'''
 +
| align="center" style="background:#f0f0f0;"|'''Winding 3'''
 +
|-
 +
| 1||0||1||Vcc||Gnd||n.c.
 +
|-
 +
| 1||0||0||Vcc||n.c.||Gnd
 +
|-
 +
| 1||1||0||n.c||Vcc||Gnd
 +
|-
 +
| 0||1||0||Gnd||Vcc||n.c.
 +
|-
 +
| 0||1||1||Gnd||n.c.||Vcc
 +
|-
 +
| 0||0||1||n.c.||Gnd||Vcc
 +
|-
 +
|
 +
|}
 +
 +
CCW (looking along the shaft toward the motor)
 +
{| {{table}}
 +
| align="center" style="background:#f0f0f0;"|'''HS 1'''
 +
| align="center" style="background:#f0f0f0;"|'''HS 2'''
 +
| align="center" style="background:#f0f0f0;"|'''HS 3'''
 +
| align="center" style="background:#f0f0f0;"|'''Winding 1'''
 +
| align="center" style="background:#f0f0f0;"|'''Winding 2'''
 +
| align="center" style="background:#f0f0f0;"|'''Winding 3'''
 +
|-
 +
| 1||0||1||Gnd||Vcc||n.c.
 +
|-
 +
| 1||0||0||Gnd||n.c.||Vcc
 +
|-
 +
| 1||1||0||n.c||Gnd||Vcc
 +
|-
 +
| 0||1||0||Vcc||Gnd||n.c.
 +
|-
 +
| 0||1||1||Vcc||n.c.||Gnd
 +
|-
 +
| 0||0||1||n.c.||Vcc||Gnd
 +
|-
 +
|
 +
|}
 +
 +
To find this data:
 +
* Go to https://support.maxonmotor.com/
 +
* Guest Login
 +
* Search for commutation sequence
 +
* First link is "Block Commutation Sequence of maxon EC motors"
 +
 +
I duplicated the tables here because the text on the site is generated by Javascript, the frame URL contains a session ID, and the back button doesn't work.
  
 
==Articles==
 
==Articles==
−
[http://www.engin.umich.edu/group/ctm/examples/motor/motor.html Modeling a DC motor]
+
*[http://www.engin.umich.edu/group/ctm/examples/motor/motor.html Modeling a DC motor]
−
[http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=5042 Brush-Less Motor Simulink]
+
*[http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=5042 Brush-Less Motor Simulink]
  
 
==Links==
 
==Links==
Line 98: Line 150:
 
*[[RoboCupElectrical|Electrical System]]
 
*[[RoboCupElectrical|Electrical System]]
 
* '''Motor Datasheet:''' [[Media:07_197_e.pdf]]
 
* '''Motor Datasheet:''' [[Media:07_197_e.pdf]]
 +
 +
[[Category: RC Electrical]]
 +
 +
[[Category:2007-2008]]

Latest revision as of 20:01, 24 May 2020

In 2008 RoboCup switched to brushless DC motors. While brushless motors are smaller and far more efficient than brushed motors the commutation normally performed inside a brushed DC motor will need to be done externally using some control circuitry. There are two main parts to our brushless motor controller solution; the controller which uses sensors on the motor to gate signals to one of three coils, and the half-bridge motor drivers which actually drive the coils.For the controller a special-purpose brushless motor driver IC was used. For information on the motors or motor control software please see their respective pages.

Tasks

  • [ ] Get the motor and begin playing with it
    • [X] Call Maxon and get a recommendation on motor drivers (Note: Already have design for motor drivers)
    • [X] Figure out max current draw. (10A starting current)
    • [X] Develop Model of Motor and get Frequency Response (Note: This is a task to be covered in firmware)
    • [X] Find and purchase Flat Flex Cable (FFC) connectors (Note: Found one)
    • [X] Purchase large mosfets for testing (Note: Test rig built and verified with drive motors)
    • [X] Purchase Surfboard for mounting DSC
    • [X] Build test rig
  • [X] Finalize on a DSC (Note: No DSC this year. Doing it in logic)
  • [X] Choose MOSFETS
  • [X] Sample all the parts
  • [X] Schematic Design
  • [ ] Build prototype
  • [ ] Prototype evaluation
    • [ ] Verify current draw under load especially start-up
    • [ ] Check if there is any temp rise in FETs in continuous operation
  • [ ] Make necessary changes

Specifications

Motor Controller Chip

MOSFET

  • See below for the parts to be used this year
  • NMOS and a PMOS
  • The FETS have to be able to handle 10A on current
  • Matrix of Potential FETS

Schematics

  • Brushless Motor Driver Schematic

Parts

We are performing commutation on the FPGA with gate drivers.

Gate Driver

Microchip TC4428

  • 1.5 A
  • 6 mA quiescent
  • Noninverting low side
  • Inverting high side

FETS

Part No. Make Package ContIDS MaxIDS Rds MaxVGS Samples Data Sheet
NTMS4503N N-Channel ON Semi SO-8 14 A -- -- 28 V Y [1]
NTMS10P02 P-Channel ON Semi SO-8 10 A -- -- 20 V Y [2]

Motor Connector

Hirose FH12-11S-1SH 11 position 1 mm pitch

Commutation

CW (looking along the shaft toward the motor)

HS 1 HS 2 HS 3 Winding 1 Winding 2 Winding 3
1 0 1 Vcc Gnd n.c.
1 0 0 Vcc n.c. Gnd
1 1 0 n.c Vcc Gnd
0 1 0 Gnd Vcc n.c.
0 1 1 Gnd n.c. Vcc
0 0 1 n.c. Gnd Vcc

CCW (looking along the shaft toward the motor)

HS 1 HS 2 HS 3 Winding 1 Winding 2 Winding 3
1 0 1 Gnd Vcc n.c.
1 0 0 Gnd n.c. Vcc
1 1 0 n.c Gnd Vcc
0 1 0 Vcc Gnd n.c.
0 1 1 Vcc n.c. Gnd
0 0 1 n.c. Vcc Gnd

To find this data:

I duplicated the tables here because the text on the site is generated by Javascript, the frame URL contains a session ID, and the back button doesn't work.

Articles

Links


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