Renesas Electronics America Inc. © 2012 Renesas Electronics America Inc. All rights reserved. Class ID: Know your Precise Position with RX600 MCU Huangsheng Xu, Engineering Unit 7L01I
© 2012 Renesas Electronics America Inc. All rights reserved.2 Huangsheng Xu (Application Engineer) Six years at Renesas Primary focus on Motor Control Applications and Customer Support Twenty year experience on motor drives, power electronics, especially, sensorless vector control of PMSM motors and induction motors Published over 20 papers in IEEE journals and conference proceedings Presented “Sensorless Vector Control of PMSM Motors” at Embedded Systems Conference Three U.S. patents Ph.D. degree in EE from Texas A&M University
© 2012 Renesas Electronics America Inc. All rights reserved.3 Renesas Technology & Solution Portfolio
© 2012 Renesas Electronics America Inc. All rights reserved.4 Microcontroller and Microprocessor Line-up Wide Format LCDs Industrial & Automotive, 130nm 350µA/MHz, 1µA standby 44 DMIPS, True Low Power Embedded Security, ASSP 165 DMIPS, FPU, DSC 1200 DMIPS, Performance 1200 DMIPS, Superscalar 500 DMIPS, Low Power 165 DMIPS, FPU, DSC 25 DMIPS, Low Power 10 DMIPS, Capacitive Touch Industrial & Automotive, 150nm 190µA/MHz, 0.3µA standby Industrial, 90nm 200µA/MHz, 1.6µA deep standby Automotive & Industrial, 90nm 600µA/MHz, 1.5µA standby Automotive & Industrial, 65nm 600µA/MHz, 1.5µA standby Automotive, 40nm 500µA/MHz, 35µA deep standby Industrial, 40nm 200µA/MHz, 0.3µA deep standby Industrial, 90nm 1mA/MHz, 100µA standby Industrial & Automotive, 130nm 144µA/MHz, 0.2µA standby bit 8/16-bit
© 2012 Renesas Electronics America Inc. All rights reserved.5 Enabling the Smart Society Green Power Home Appliances Industrial Automation Automotive Medical & Fitness
© 2012 Renesas Electronics America Inc. All rights reserved.6 How Much Experience Do You Have with Renesas Microcontrollers and Position Control? 1.Extensive 2.Moderate 3.Low 4.None
© 2012 Renesas Electronics America Inc. All rights reserved.7 Agenda Lab Overview (5 minutes) Introduce RX Position Control (20 minutes) Basic Position Control Theory Proposed Two-loop Position Control Hall Sensor and Encoder for Position Measurement Rx62T Position Control Strategy and Implementation Lab (70 minutes) Lab Procedures Play Time and Q&A (15 minutes)
© 2012 Renesas Electronics America Inc. All rights reserved.8 External drive connector RPM SetStandalone operation control Hall Encoder Motor 24VDC Power Supply Motor E1 Emulator BLDC Motor Rx62T MCU GUI USB Lab Set-up
© 2012 Renesas Electronics America Inc. All rights reserved.9 Jumper Assignments OperationJP6JP7JP8JP9JP10JP11JP12JP13JP14JP15 External OPA 3 - Shunt1 - 2 –– 1 - Shunt–1 - 2 – Internal PGA 3 - Shunt1 - 2 –– Shunt–1 - 2 –
© 2012 Renesas Electronics America Inc. All rights reserved.10 GUI Position Control Window
© 2012 Renesas Electronics America Inc. All rights reserved.11 Motors Used for Position Control Stepper Motors DC Motors Positioning mechanism is simple Motor displacement under heavy load Motor capacity is small Poor precision at high speed Good precision Maintenance required for brushes Not suitable for high rotation speed AC Motors Good precision No maintenance required Positioning address can be easily changed Compact yet offer high power Position Control Motors
© 2012 Renesas Electronics America Inc. All rights reserved.12 Position Control Strategy Two-Loop Position Control Position loop: The position measured by encoder is compared with the commanded position through the PID controller to generate the torque current Current loop: Generates the required torque from position loop to move the motor to the commanded position (faster loop)
© 2012 Renesas Electronics America Inc. All rights reserved.13 Position Measurement by Encoder Two channels of Quadrature pulses allow sensing relative position, direction and speed of rotation Third channel “Z”-Pulse, once per rotation, provides an absolute reference Position accuracy is based on resolution or number of lines per revolution
© 2012 Renesas Electronics America Inc. All rights reserved.14 Encoder Signals A leads B -> Count Up B leads A -> count down Z provides absolute reference to rotor position Count = Position Speed = ∆Position / ∆t A B Z Angle = 0 counts Angle = 18 counts Angle = 34 counts One revolution
© 2012 Renesas Electronics America Inc. All rights reserved.15 RX62T Encoder Capture Function
© 2012 Renesas Electronics America Inc. All rights reserved.16 Position Calculation by RX62T
© 2012 Renesas Electronics America Inc. All rights reserved.17 Initial Position Using Hall Sensors at Start-up Encoder cannot provide initial position information Hall sensors are used for the initial position measurement First hall sensor signal change is captured to correct the position After start-up, position is counted and controlled by the encoder
© 2012 Renesas Electronics America Inc. All rights reserved.18 Position Control Implementation Two-loop control Outer position loop Inner current loop - use field oriented control PID controller is used
© 2012 Renesas Electronics America Inc. All rights reserved.19 Trajectory Generation The motion profile engine uses 5 variables: Angular Acceleration (degrees/sec2) Angular Velocity (degrees/sec) Angular Deceleration (degrees/sec2) Angular Accel/Decel “S” profile (%) Angular Distance (degrees) Encoder counts are used as units for these variables
© 2012 Renesas Electronics America Inc. All rights reserved.20 Position and Current Controller Tuning Position PID controller Id& Iq Current PI controller Kp & Ki are calculated by motor parameters and controller BW 1. Tune Kp by checking the dynamic response 2. Slowly increase Ki so that steady state error = 0
© 2012 Renesas Electronics America Inc. All rights reserved.21 Position Control Software Architecture
© 2012 Renesas Electronics America Inc. All rights reserved.22 Position Measurement Implementation Diagram
© 2012 Renesas Electronics America Inc. All rights reserved.23 Position Control Implementation Diagram
© 2012 Renesas Electronics America Inc. All rights reserved.24 Lab Procedures Phase 1: Set up position control lab (10 minutes) Phase 2: Measure motor position using Hall sensor and encoder (20 minutes) Phase 3: Drive motor by closing position control loop (20 minutes) Phase 4: Learn position controller tuning (20 minutes)
© 2012 Renesas Electronics America Inc. All rights reserved.25 Start Lab Please refer to the lab handout Go ahead and start the lab
© 2012 Renesas Electronics America Inc. All rights reserved.26 Questions? Questions?
© 2012 Renesas Electronics America Inc. All rights reserved.27 Summary Through the Lab, you will be able to learn How to use Renesas HEW with Rx62T Microcontroller Motor Position Measurement using Hall Sensors and Encoder Encoder Alignment with Hall Sensors Two-Loop Position Control Strategy and implementation Closing Position Control Loop to Drive Motor to Desired Positions Position Control Parameter Tuning
© 2012 Renesas Electronics America Inc. All rights reserved.28 Enabling the Smart Society Green Power Home Appliances Industrial Automation Automotive Medical & Fitness
© 2012 Renesas Electronics America Inc. All rights reserved.29 Please utilize the ‘Guidebook’ application to leave feedback or Ask me for the paper feedback form for you to use… Please Provide Your Feedback…
Renesas Electronics America Inc. © 2012 Renesas Electronics America Inc. All rights reserved.