Selection of controllers and integrated systems

Transcription

1 maxon motor: Selection of controllers and integrated systems 2017 maxon motor ag maxon_control-system-selection, WJ, Animated Version V2.31 Criteria to find the base drive controller family Base criteria 1: Control functionality? Control Issues Position? Speed? Torque? 1 1

2 Criteria to find the base drive controller family Base criteria 1: Control functionality? Digital Command Set Value Path Generator Actual Value Pos Speed Ramp Speed /Position Control t Motion / Positioning Controller Path generator + Position control Servo controller 4Q power stage Processing sensor signals Speed & Current control Current Set Value Actual Current Current Control Feedback Driver, Power Amplifier 4Q 2 Criteria to find the base drive controller family Base criteria 1: Control functionality depending on application Current or Torque control, e.g. in case of a demand for a fixed or adjustable motor torque. an electrical screwdriver, pressing tool, strapping tool, Speed control, e.g. in case of a demand for a fixed or adjustable speed (independent of load). a fan, drill, pump, centrifuge, conveyor belt, scanner, Position control, e.g. in case of any precise angular or linear movement to a defined position. an X/Y table, turntable, robot, pick-and-place device, door drive, 3 2

3 Criteria to find the base drive controller family Base criteria 2: Type of commanding Commanding by analog or digital signals Standalone operation or commanding by I/O signals (e.g. PLC, C) Analog and digital I/Os with configurable functionality. Commanding by a bus or serial interface Master controller, e.g. PLC, PC, Raspberry Pi, BeagleBone, C, ) USB, RS232, CAN, EtherCAT, or??? interface. Commanding by a fast, predictable, cyclic data exchange Real time master controller is mandatory! CAN, EtherCAT, or??? Interface. 4 Your notes 5 3

4 maxon motor control: Base product lines 2017 DEC Module ESCON EPOS2 / EPOS4 MAXPOS EPOS2 / EPOS4 EPOS4 only (optional) Controller 1-Q speed controller 4-Q current / speed controller 4-Q motion controller Highly dynamic 4-Q motion controller Control task Speed (open loop) Speed (closed loop) Current controller Speed (open loop) Speed (closed loop) Current controller Speed (closed loop) Positioning controller Current controller Speed (closed loop) Positioning controller Commanding Analog and digital signals Analog and digital signals typically with MASTER and bus communcition e.g. PLC, PC, C EtherCAT-MASTER mandatory (e.g. PLC, RTOS) Remark High-volume projects Configuration by input signals Flexible configuration by USB and PC software tool Housed, open frame, module versions Base for customized controllers USB, RS232, CAN + EtherCAT (EPOS4) PC software tool for configuration Windows & Linux Libraries for PC, Raspberry Pi, BeagleBone EtherCAT only Ethernet, USB for configuration only PC software tool for configuration 6 Selection based on application requirements End user device DEC ESCON EPOS2/EPOS4 MAXPOS RS232 Screw driver, Drill, Pressing or strapping tool, Fan, Pump, Roller blind, Conveyor belt, Centrifuge, Scanner, Open/Close - Door drive, On/Off - Valve, X/Y table, turntable, Valve, Door drive, Robot, Pick-and-Place, Multi-axis position control & drive synchronization, ( ) 1 st choice Bus 1 st choice ( ) ( ) 1 ( ) st choice 1 st choice 1Q 4Q 4Q 4Q 1 st choice commanding Bus commanding 1 st choice 1 st choice ( ) 1 st choice 7 4

5 Criteria to find the right product type Additional criteria: Size, mounting, system integration Modules "Motion Control" plug-in for integration in an electronic design. Additional electronics development (e.g. motherboard) required. Typically in use for medium and high volume applications. Space-saving, most compact in size. 8 Criteria to find the right product type Additional criteria: Size, mounting, system integration Compact / Open Frame Compact size with integrated connectors for all signals. Easy to mount close to the motor or in an electrical cabinet. For single piece applications, small and medium volume demand. Ready to use with optional cables. 9 5

6 Criteria to find the right product type Additional criteria: Size, mounting, system integration Housed Electronic board covered by a robust metal housing. Different kinds of mounting. Typically in use in an electrical cabinet or mounted on a machine. 10 Criteria to find the right product type Additional criteria: Size, mounting, system integration Integrated Motor and electronics integrated in one housing Catalog products + customized solutions Customized solutions maxon MCD with integrated positioning control maxon EC-flat i.e. with integrated speed control 11 6

7 Criteria to find the right product type Additional criteria? Supply Supply voltage Type of power supply ( Capability to handle reversed energy?) Special environmental conditions Operating temperature range ( Derating of technical data?) Humidity ( Coated electronics?) Vibration ( Mounting, components in use?) Pressure ( Components in use?) Special standards (Aerospace, Medical, Military, Subsea, ) 12 The solution triangle Commercial Issues Target price Quantity / year Market share Application's Requirements Solution Control Issues Position Velocity Torque Inhouse Experience or Add-on Engineering Motion Control? Programming? System/Control Design? System Environment Power & size constraints? Master or Standalone? Commanding: I/O or bus? Data Exchange: real-time? 13 7

8 Special demands? Customized solution instead of a catalog product? Commercial aspect -> Fully cost-optimized High-volume demand. Cost-optimization by getting rid of all components / connectors not needed. Special connectors adapted to existing cables for cost-optimized assembly. Special PCB design Controller's PCB has to fit into a given space (e.g. special PCB for a hand tool, ) Add-on hardware features Controller has to integrate additional components (e.g. LCD, brake chopper, ) 14 Special demands: Modification / Customization Firmware Modification Customization typ. 1 5 days of work HW- Components typ. 1 6 months of work New design based on another mmc product Integration of motor and control Low-cost, high volume control design Increasing level of effort (period of time + costs) 15 8

9 Modification business Modification = Limited adaptations to catalog products Enhanced functionality for special applications: Preconfiguration Modified firmware features PCB coating Reduced current limits Typically a total effort of 1-5 days for development, testing, and update of documents. The resulting product (very often) looks the same like the catalog product 16 Customization business Customization = Development of a fully tailor-made product Individual electronics designs for creative ideas! Enhanced, new features to fit special requirements! Cost-optimized solutions for high-volume series products! High effort for specification, development, test, and documentation, typ. 3 6 months 18 9

10 Steps to go for a fully customized product Everybody seems to "know" what is expected Hidden tasks & challenges End user: Let us automate the door! The required features look quite simple. The solution also has to be quite simple from the user's point of view. 20th Century Fox 20 10

11 20th Century Fox Obvious requirements of the end user Press button "Open" Open the two parts of the door simultaneously. Press button "Close" Close the two parts of the door simultaneously. Any button for "Stop" or automatic "Stop"? e.g. in case of something going wrong. Special points to take care about All movement should be smooth with less noise Make sure nobody is injured by the movement "Best possible price" 21 The engineer's first focus: Technical data Required technical details / data Speed, Torque, Load, Inertia Cycle times Mechanical dimensions Protection levels 22 11

12 20th Century Fox The engineer: System requirements? Functional requirements Open / close the doors of an elevator. What has to happen when? (Even in case of an error state or malfunction.) What safety level and standards have to be fulfilled? System design Usability Service handling and future service costs Lifetime expectations & operational availability Integration in the system environment Commercial aspects (e.g. "Best price / feature ratio") 23 Customization -> The "hidden" challenges Comprehensive engineering tasks Mechanical engineering Electronics hardware development Firmware development (Add-on features, customized protocols, ) Verification of required standards Test of module & complete system Project management & Documentation Specification, Design concepts, Implementation, Verification Rule of thumb: At least 30% of the effort is project management, testing, and documentation

13 Customization = Engineering business Process steps to go through: Requirements Analysis Feasibility Study Design Implementation Integration Verification Aim: Get a common and identical understanding of the requirements. Aim: Evaluation and checking concepts, feasibility, risk, and effort. Aim: Hardware, firmware, and mechanical engineering. Aim: Hardware, firmware, and mechanical development. Aim: Putting everything together to one system. Aim: Testing and finalization of documentation. Artifact: Requirements specification Artifact: Design specification Artifacts: HW-/FWarchitecture documentation Artifacts: Schematics, layouts, source code Artifacts: User manual, test plan Artifacts: Final product specification, test report 25 maxon motors and controllers set the world into motion 26 13

14 The complete solution?! System design. Looking beyond one's own nose. Get an overall system view. System design & components Sensors HMI: Human Machine Interface G Actuators Motor E Data base Master (Process) Controller Bus communication (Real time?) data exchange Motion Controller #1 #n #2 Worldwide network Power Supply 28 14

15 Understanding system levels & interfaces Integration level: Machine, Device, Hand tool, customer System Controller Drive Controller Electromechanical Drive unit User Interface Application Software Communication Interface Signal & Power lines Level 3 + 4: System & User Interface Engineering Level 1 + 2: Drive Engineering 29 Focus on application demands! Understand the expectations of the end user. Take functional, non-functional, and technical data into account! Get an overall system view. 15

16 Thinking further A drive system consists not only of a controller, hence What are the requirements for the master and the bus system? What to consider when selecting the motor? The sensor must be crucial for the position accuracy, isn t it? Where are the traps and hidden dependencies? 31 Thinking further. System performance Rule of thumb Higher level controller can be 10 times slower Requirement for bus performance Current control sampling rate = 100 khz => commanding with 0.1 ms sampling is reasonable Speed / position controller = 10 khz => commanding with 1 ms sampling is sufficient 32 16

17 Thinking further. Maximum dynamics Dynamics Dynamics = acceleration performance Maximum dynamics = mechanical time constant Influencing factors Motor design Mechanics at motor output Power supply & available peak currents 33 Thinking further. High dynamic motors Low mass inertia Low torque needed for motor acceleration High overload capability High peak torques for fast acceleration High efficiency Energy goes into motion! From 0 to nominal speed in milliseconds! 100% 34 17

18 Thinking further. Position accuracy Theory: Position accuracy Position accuracy = sensor resolution In practical: Influencing factors Backlash, mechanical play (e.g. gears) Elasticity (e.g. couplings, belts), slip Sensor accuracy Not optimally tuned controlled parameters 35 Thinking further. Traps: Power train Acceleration / deceleration: High motor currents! Energy recovery (-> back feeding)! Motor Cyclic motion: RMS current <= max. continuous motor current? Power stage of motion controller Continuous / max. current (duration) sufficient? Power supply Peak currents, capability to handle energy recovery, buffering capacities,...? 36 18

19 Conclusion: The Solution is more than drive engineering and single components. has to be focused on the comprehensive requirements. (Even soft factors!) 2017 maxon motor ag WJ, Join the spirit of success! 19