Manuals / RoboteQ / Computer Equipment / Computer Hardware

RoboteQ AX1500 Battery Current vs. Motor Current, Motor Current = Battery Current / PWM ratio

Models: AX2550 AX1500

1 186

Download 186 pages 53.05 Kb

Page 43

Battery Current vs. Motor Current

Battery Current vs. Motor Current

The numbers in the table are the max Amps allowed by the controller at a given tempera- ture point. If the Amps limit is manually set to a lower value, then the controller will limit the current to the lowest of the manual and temperature-adjusted max values.

This capability ensures that the controller will be able to work safely with practically all motor types and will adjust itself automatically for the various load and environmental con- ditions. The time it takes for the heat sink’s temperature to rise depends on the current output, ambient temperature, and available air flow (natural or forced).

Note that the measured temperature is measured on the PCB near the Power Transistors and will rise and fall faster than the outside surface.

Battery Current vs. Motor Current

The controller measures and limits the current that flows from the battery. Current that flows through the motor is typically higher. This counter-intuitive phenomenon is due to the “flyback” current in the motor’s inductance. In some cases, the motor current can be extremely high, causing heat and potentially damage while battery current appears low or reasonable.

The motor’s power is controlled by varying the On/Off duty cycle of the battery voltage 16,000 times per second to the motor from 0% (motor off) to 100 (motor on). Because of the flyback effect, during the Off time current continues to flow at nearly the same peak - and not the average - level as during the On time. At low PWM ratios, the peak current - and therefore motor current - can be very high as shown in Figure 18, “Instant and average current waveforms,” on page 44.

The relation between Battery Current and Motor current is given in the formula below:

Motor Current = Battery Current / PWM ratio

Example: If the controller reports 10A of battery current while at 10% PWM, the current in the motor is 10 / 0.1 = 100A.

AX1500 Motor Controller User’s Manual

43

Image 43

RoboteQ AX1500, AX2550 user manual Battery Current vs. Motor Current, Motor Current = Battery Current / PWM ratio

Contents

AX1500 Dual Channel Digital Motor ControllerUser’s Manual Version 1.9b. June 1 AX1500 Motor Controller User’s ManualVersion Revision HistoryRevision History DateVersion 1.9b. June 1 AX1500 Motor Controller User’s ManualRevision History General Operation Recommended Encoder Types SECTION Connector I/O Pin Assignment RS232 Mode Controller Identification Register Logging Data to Disk Version 1.9b. June 1 AX1500 Motor Controller User’s ManualWarnings Important SafetyAvoid Shorts when Mounting Board against Chassis Do not Connect to a RC Radio with a Battery AttachedAX1500 Motor Controller User’s Manual Important Safety WarningsVersion 1.9b. June 1 What you will need Locating the ConnectorsAX1500 Quick StartAX1500 Motor Controller User’s Manual AX1500 Quick StartConnecting to the Batteries and Motors Connecting to the Batteries and MotorsAX1500 Motor Controller User’s Manual RC Mode Connecting to the 15-pin ConnectorImportant Warning SignalAX1500 Motor Controller User’s Manual Connecting the R/C RadioConnecting the R/C Radio Important WarningAX1500 Quick Start Powering On the ControllerDefault Controller Configuration Default ValuesConnecting the controller to your PC using Roborun Connecting the controller to your PC using RoborunAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual Obtaining the Controller’s Software Revision NumberExploring further AX1500 Quick StartProduct Description SECTION 3AX1500 Motor Controller OverviewAX1500 Motor Controller User’s Manual AX1500 Motor Controller Overview Technical featuresMultiple Command Modes Automatic Joystick Command CorrectionsOptical Encoder Inputs optional Technical featuresLow Power Consumption High Efficiency Motor Power OutputsCompact Open Frame PCB Design Advanced Safety FeaturesAX1500 Motor Controller Overview Data Logging CapabilitiesImportant Warning Connecting Power and Motors to the ControllerPower Connections Power ConnectionsConnecting Power and Motors to the Controller Controller PowerAX1500 Motor Controller User’s Manual mended Off Configuration Controller PowerPower Control input is And Main BatteryPower Control input is Controller Powering SchemesPowering the Controller from a single Battery Connecting Power and Motors to the ControllerAX1500 Motor Controller User’s Manual Powering the Controller Using a Main and Backup BatteryController Powering Schemes Important WarningImportant Warning Connecting the MotorsConnecting Power and Motors to the Controller Important WarningAX1500 Motor Controller User’s Manual Single Channel OperationConverting the AX1500 to Single Channel Single Channel OperationImportant Warning Power FusesWire Length Limits Connecting Power and Motors to the ControllerElectrical Noise Reduction Techniques Power Regeneration ConsiderationsElectrical Noise Reduction Techniques Important WarningConnecting Power and Motors to the Controller Using the Controller with a Power SupplyOvervoltage Protection Undervoltage ProtectionAX1500 Motor Controller User’s Manual Using the Controller with a Power SupplyAX1500 Motor Controller User’s Manual Connecting Power and Motors to the ControllerVersion 1.9b. June 1 Basic Operation Input Command ModesGeneral Operation Basic OperationGeneral Operation Selecting the Motor Control ModesOpen Loop, Separate Speed Control Open Loop, Mixed Speed ControlAX1500 Motor Controller User’s Manual Closed Loop Speed ControlClose Loop Position Control Selecting the Motor Control ModesPosition Feedback Position Sensor Gear box User Selected Current Limit SettingsTemperature-Based Current Limitation TemperatureAX1500 Motor Controller User’s Manual Battery Current vs. Motor CurrentBattery Current vs. Motor Current Motor Current = Battery Current / PWM ratioGeneral Operation Regeneration Current LimitingMotor Current = Battery Current / PWM Ratio Important WarningSwitches Programmable AccelerationSetting Using Setting UsingSwitches Command Control CurvesSetting Using Setting UsingSelected Curve Left / Right Tuning AdjustmentLeft / Right Tuning Adjustment Exponentiation Parameter ValueParameter Value Speed AdjustmentSpeed Adjustment General OperationSpeed Adjustment Emergency Stop using External SwitchActivating Brake Release or Separate Motor Excitation Inverted OperationGeneral Operation Special Use of Accessory Digital InputsUsing the Inputs to Activate the Buffered Output Using the Inputs to turn Off/On the Power MOSFET transistorsAX1500 Motor Controller User’s Manual Connecting Sensors and Actuators to Input/OutputsAX1500 Connections AX1500 ConnectionsConnecting Sensors and Actuators to Input/Outputs AX1500’s Inputs and OutputsAX1500 Motor Controller User’s Manual Activated SignalAX1500’s Inputs and Outputs I/O typeSignal depending Pin1I/O List and Pin Assignment Connecting Sensors and Actuators to Input/Outputson Mode Connecting devices to Output CConnecting devices to Output C Signal dependingConnecting Sensors and Actuators to Input/Outputs Connecting Switches or Devices to Input EConnecting Switches or Devices to Input F Important warningConnecting Switches or Devices to EStop/Invert Input Connecting Switches or Devices to EStop/Invert InputAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual Connecting Position Potentiometers to Analog InputsAnalog Inputs Connecting Sensors and Actuators to Input/OutputsImportant Warning Connecting Tachometer to Analog InputsConnecting Tachometer to Analog Inputs Operating ModeAna 1 p11 Connecting Sensors and Actuators to Input/OutputsOperating Mode Important WarningResistance kOhm Connecting External Thermistor to Analog InputsConnecting External Thermistor to Analog Inputs Temp oCConnecting Sensors and Actuators to Input/Outputs Using the Analog Inputs to Monitor External VoltagesAX1500 Motor Controller User’s Manual Connecting User Devices to Analog Inputs Connecting User Devices to Analog InputsInternal Heatsink Temperature Sensors Internal Voltage Monitoring SensorsValue Temperature Conversion C Source CodeConnecting Sensors and Actuators to Input/Outputs AX1500 Motor Controller User’s ManualLoTemp = i * 5 Internal Heatsink Temperature SensorsAX1500 Motor Controller User’s Manual elseAX1500 Motor Controller User’s Manual Connecting Sensors and Actuators to Input/OutputsVersion 1.9b. June 1 AX1500 Motor Controller User’s Manual Installing Connecting and Using the Encoder ModuleOptical Incremental Encoders Overview Optical Incremental Encoders OverviewInstalling, Connecting and Using the Encoder Mod Recommended Encoder TypesAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual Installing the Encoder ModuleInstalling the Encoder Module Pulse Frequency in Hz = RPM / 60 * PPRInstalling, Connecting and Using the Encoder Mod Connecting the EncoderAX1500 Motor Controller User’s Manual Cable Color Cable Length and Noise ConsiderationsCable Length and Noise Considerations NameImportant Warning Voltage Levels, Thresholds and Limit SwitchesMotor - Encoder Polarity Matching Installing, Connecting and Using the Encoder ModAX1500 Motor Controller User’s Manual Wiring Optional Limit SwitchesWiring Optional Limit Switches Important WarningWhen the switch is activated, the module’s input is pulled to Installing, Connecting and Using the Encoder ModAX1500 Motor Controller User’s Manual Motor 1 Fwd Wiring Limit Switches Without EncodersEffect of Limit Switches Wiring Limit Switches Without EncodersMotor 2 Fwd Using the Encoder Module to Measure DistanceUsing the Encoder to Measure Speed Installing, Connecting and Using the Encoder ModAX1500 Motor Controller User’s Manual Using the Encoder to Track PositionImportant Notice Using the Encoder to Track PositionDistance = Destination - Counter value / Divider RS232 Communication with the Encoder ModuleInstalling, Connecting and Using the Encoder Mod Important NoticeEncoder Testing and Setting Using the PC Utility Encoder Testing and Setting Using the PC UtilityAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual Installing, Connecting and Using the Encoder ModVersion 1.9b. June 1 Mode Description Closed Loop Position ModeMode Description Selecting the Position ModePosition Feedback Position Sensor Gear box Position Sensor SelectionSensor Mounting Closed Loop Position ModeImportant Notice Feedback Potentiometer wiringFeedback Potentiometer wiring in RC or RS232 Mode Feedback Potentiometer wiringAX1500 Motor Controller User’s Manual Feedback Potentiometer wiring in Analog ModeClosed Loop Position Mode Important NoticeImportant Notice Feedback Wiring in RC or RS232 Mode on Single Channel ControllersFeedback Wiring in Analog Mode on Single Channel Controllers Analog Feedback on Single Channel ControllersImportant Warning Using Optical Encoders in Position ModeSensor and Motor Polarity Closed Loop Position ModeEncoder Error Detection and Protection Important Safety WarningEncoder Error Detection and Protection Adding Safety Limit SwitchesFIGURE 53. Safety limit switches interrupting power to motors Closed Loop Position ModeAX1500 Motor Controller User’s Manual Important Warning Using Current Limiting as ProtectionControl Loop Description Using Current Limiting as ProtectionClosed Loop Position Mode PID tuning in Position ModeAX1500 Motor Controller User’s Manual Applied Power = Command Value - Actual Position * Proportional Gain PID tuning in Position ModeAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual Closed Loop Position ModeVersion 1.9b. June 1 Mode Description Closed Loop Speed ModeSelecting the Speed Mode Using Optical Encoder for Speed FeedbackDigital Optical EncodAX1500 Motor Controller User’s Manual Tachometer wiringTachometer or Encoder Mounting Closed Loop Speed ModeAX1500 Motor Controller User’s Manual Speed Sensor and Motor PolarityImportant Warning Speed Sensor and Motor PolarityControl Loop Description Adjust Offset and Max SpeedClosed Loop Speed Mode Important WarningPID tuning in Speed Mode PID tuning in Speed ModeAX1500 Motor Controller User’s Manual In Speed Mode, the Integral component of the PID is the most important and must be set first. The Proportional and Differential component will help improve the response time and loop stability Closed Loop Speed ModeAX1500 Motor Controller User’s Manual Normal Operation Flashing Pattern Normal and Fault Condition LED MessagesPower On LED Diagnostic LEDNormal and Fault Condition LED Messages Output Off / Fault ConditionAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual SECTION 11 R/C OperationMode Description Mode DescriptionPin1 Selecting the R/C Input ModeConnector I/O Pin Assignment R/C Mode SignalR/C Input Circuit Description R/C Input Circuit DescriptionSupplied Cable Description SignalFIGURE 65. RC connection cable Powering the Radio from the controllerFIGURE 64. RC Cable wiring diagram R/C OperationWire loop bringing power from controller to RC radio Powering the Radio from the controller3 Channel 1 Command Pulses 4 Channel 2 Command Pulses 6 Radio battery - Ground 7 Radio battery + 8 Channel 3 Command PulsesAX1500 Motor Controller User’s Manual Connecting to a Separately Powered RadioOperating the Controller in R/C mode R/C OperationReception Watchdog Reception WatchdogAX1500 Motor Controller User’s Manual R/C Operation Important Notice about PCM RadiosR/C Transmitter/Receiver Quality Considerations Joystick Deadband ProgrammingDeadband as Percent of full Joystick Travel Command Control CurvesCommand Control Curves Deadband Parameter ValueR/C Operation Left/Right Tuning AdjustmentActivating the Accessory Outputs Joystick CalibrationData Logging in R/C Mode Data Logging in R/C ModeAX1500 Motor Controller User’s Manual To Controller R/C OperationAX1500 Motor Controller User’s Manual DB15 MaleImportant Notice Analog Control and OperationMode Description Mode DescriptionAnalog Control and Operation Connector I/O Pin Assignment Analog ModeSignal Pin1AX1500 Motor Controller User’s Manual Connecting to a Voltage SourceConnecting a Potentiometer Connecting to a Voltage SourceImportant Notice Selecting the Potentiometer ValueAnalog Deadband Adjustment Motor Power at 0% Power-On SafetyUnder Voltage Safety Data Logging in Analog ModeAX1500 Motor Controller User’s Manual Data Logging in Analog ModeAX1500 Motor Controller User’s Manual Analog Control and OperationVersion 1.9b. June 1 AX1500 Motor Controller User’s Manual Serial RS-232 Controls and OperationUse and benefits of RS232 Use and benefits of RS232Serial RS-232 Controls and Operation Connector I/O Pin Assignment RS232 ModeSignal Pin1AX1500 Motor Controller User’s Manual Cable configurationExtending the RS232 Cable Cable configurationSerial RS-232 Controls and Operation Communication Settings9600 bits/s, 7-bit data, 1 Start bit, 1 Stop bit, Even Parity Establishing Manual Communication with a PCAX1500 Motor Controller User’s Manual RS232 Communication with the Encoder ModuleEstablishing Manual Communication with a PC Roboteq v1.9b 06/01/07 sAX1500 Motor Controller User’s Manual Entering RS232 from R/C or Analog modeData Logging String in R/C or Analog mode Serial RS-232 Controls and OperationCommand Error Commands Acknowledge and Error MessagesRS232 Mode if default Command AcknowledgementSerial RS-232 Controls and Operation Controller Commands and QueriesRS-232 Watchdog CommandCommand Set Motor Command ValueSet Accessory Output Controller Commands and QueriesImportant Notice Query Power Applied to MotorsQuery Amps from Battery to each Motor Channel Important NoticeController Commands and Queries Query Heatsink TemperaturesQuery Battery Voltages Query Analog InputsSyntax Reset ControllerQuery Digital Inputs Serial RS-232 Controls and OperationRead parameter Accessing & Changing Configuration Parameter in FlashApply Parameter Changes Accessing & Changing Configuration Parameter in FlashDescription Flash Configuration Parameters ListSerial RS-232 Controls and Operation LocationAccess Input Control ModeMotor Control Mode Accessing & Changing Configuration Parameter in FlashSerial RS-232 Controls and Operation Amps LimitAccess After Reset or FFAccess Input Switches FunctionAcceleration Accessing & Changing Configuration Parameter in FlashAfter Reset or FF RC Joystick or Analog DeadbandExponentiation on Channel 1 and Channel AccessAccess Left/Right AdjustDefault Encoder Time Base 1 and Accessing & Changing Configuration Parameter in FlashAccess Default Encoder Distance DividerDefault PID Gains Joystick Min, Max and Center ValuesDefinition Reading & Changing Operating Parameters at RuntimeReading & Changing Operating Parameters at Runtime 1C - Joystick Max 2 MS 1D - Joystick Max 2 LS Effective InstantlyImportant Notice Operating Modes RegistersRead/Change PID Values AccessAddress Access Read/Write Effective Instantly PWM Frequency RegisterController Status Register 87 - D2 Access Read/Write Effective InstantlyAccess Controller Identification RegisterCurrent Amps Limit Registers Fault ConditionRS232 Encoder Command Set RS232 Encoder Command SetSet/Reset Encoder Counters and Destination Registers Read Encoder CounterAX1500 Motor Controller User’s Manual Read Speedq or !Q n SyntaxRS232 Encoder Command Set Read Encoder Limit Switch StatusRead Distance Read Speed/DistanceSwitch Important NoteRead / Modify Encoder Module Registers and Parameters SwitchAddress RS232 Encoder Command SetAccess Modify parameterSpeed or Distance 1 or Switch StatusRegister Description Encoder Hardware ID codeRegister Description Counter Read/Write MailboxCounter 1 and Destination Register 1 andEncoder Threshold Distance 1 andSpeed 1 and Time Base 1 andDecimal Counter Read Data FormatEncoder Testing and Setting Using the PC Utility Counter Read Data FormatVersion 1.9b. June 1 AX1500 Motor Controller User’s ManualAutomatic Switching from RS232 to RC Mode Automatic Switching from RS232 to RC ModeAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual 00 11 22 33 44 55 66 77 88 99 AA BB CCAnalog and R/C Modes Data Logging String Format Data Logging CablesDecimal to Hexadecimal Conversion Table Decimal to Hexadecimal Conversion TableAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual Decimal to Hexadecimal Conversion TableVersion 1.9b. June 1 AX1500 Motor Controller User’s ManualAX1500 Motor Controller User’s Manual SECTION 14 Using the Roborun Configuration UtilityDownloading and Installing the Utility System RequirementsUsing the Roborun Configuration Utility Connecting the Controller to the PCAX1500 Motor Controller User’s Manual 1- Program Revision Number Roborun Frame, Tab and Menu Descriptions3- Parameter Selection and Setting and Special Functions Roborun Frame, Tab and Menu Descriptions4- File and Program Management Commands Getting On-Screen HelpLoading, Changing Controller Parameters Using the Roborun Configuration UtilityLoading, Changing Controller Parameters Control Settings2- Motor Control Mode 3- Input Command Adjustment2- Left/Right Adjust Power SettingsUsing the Roborun Configuration Utility 4- Emergency Stop or Invert Switch Select2- Joystick Timing Analog or R/C Specific SettingsLoading, Changing Controller Parameters 1- DeadbandAX1500 Motor Controller User’s Manual Encoder Setting and TestingClosed Loop Parameters Using the Roborun Configuration UtilityEncoder Setting and Testing Encoder Module Parameters SettingAX1500 Motor Controller User’s Manual Using the Roborun Configuration Utility Running the MotorsExercising the Motors Viewing Encoder Data3- Measurement 2- Motor Power settingRunning the Motors 1- Run/Stop Button5- Transmit and Receive Data Using the Roborun Configuration Utility4- Real-Time Strip Chart Recorder 6- Input Status and Output Setting4- Reset Timer button Logging Data to DiskRunning the Motors 7- Data Logging and Timer 8- Joystick EnableParameter Header Using the ConsoleConnecting a Joystick Using the Roborun Configuration Utility3- Keep Watchdog Alive Using the Console2- Command Entry 1- Terminal ScreenUsing the Roborun Configuration Utility 4- Send Reset String Operating the AX1500 over a Wired or Wireless LANViewing and Logging Data in Analog and R/C Modes Loading and Saving Profiles to DiskAX1500 Motor Controller User’s Manual Operating the AX1500 over a Wired or Wireless LANImportant Warning Updating the Controller’s SoftwareUpdating the Encoder Software Using the Roborun Configuration UtilityCreating Customized Object Files Creating Customized Object FilesAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual Using the Roborun Configuration UtilityVersion 1.9b. June 1 AX1500 Motor Controller User’s Manual Mechanical SpecificationsMechanical Dimensions Mechanical DimensionsAX1500 Motor Controller User’s Manual Mounting ConsiderationsThermal Considerations Mechanical SpecificationsAttaching the Controller Directly to a Chassis Attaching the Controller Directly to a ChassisAX1500 Motor Controller User’s Manual Mechanical Specifications Precautions to observeAX1500 Motor Controller User’s Manual AX1500 Motor Controller User’s Manual Wire DimensionsWeight Wire DimensionsAX1500 Motor Controller User’s Manual Mechanical SpecificationsVersion 1.9b. June 1