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RoboteQ AX2850 user manual Regeneration Current Limiting, Off

Models: AX2850

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General Operation

Vbat

On

Motor

Off

FIGURE 19. Current flow during operation

On	Off
	I mot
	Avg
	I bat
	Avg

FIGURE 20. Instant and average current waveforms

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.

Important Warning

Do not connect a motor that is rated at a higher current than the controller. While the battery current will never exceed the preset Amps limit, that limit may be reached at a PWM cycle lower than 100% resulting in a higher and potentially unsafe level through the motor and the controller.

Regeneration Current Limiting

The AX2550’s current sensor is capable of measuring current in the reverse flow (regener- ation). Using this capability, the controller will automatically relax the braking effect of the power output stage to keep the regeneration current within safe values. Because of the controller’s high current handling capabilities, this protection mechanism activates only when abrupt deceleration are applied to high-inertia, ultra-low impedance motors.

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AX2550 Motor Controller User’s Manual

Version 1.9b. June 1, 2007

Image 46

RoboteQ AX2850 user manual Regeneration Current Limiting, Off

Contents

Dual Channel High Power Digital Motor Controller AX2550 AX2850 AX2550 Motor Controller User’s Manual Revision History Revision HistoryDate Version Changes AX2550 Motor Controller User’s Manual Section Section Installing, Connecting and Using the Encoder Module 100 127 152 177 AX2550 Motor Controller User’s Manual Important Safety Beware of Motor Runaway in Improperly Closed Loop Important Safety Warnings Quick Start Locating the Switches, Wires and ConnectorsAX2550 What you will need AX2550 Quick Start Optical Encoders Program LED Sensors AX2850 only Display Connecting to the Batteries and Motors Connecting to the Batteries and Motors Connecting to the 15-pin Connector Signal Pin RC Mode RS232 Mode Analog Mode Connecting the R/C Radio Connecting the R/C Radio Button Operation Powering On the ControllerProg and Set button status Function Default Controller Configuration Default Controller ConfigurationParameter Default Values Letter Connecting the controller to your PC using Roborun Obtaining the Controller’s Software Revision Number Obtaining the Controller’s Software Revision Number Exploring further = Software version 1.9b AX2550 Motor Controller Overview Product Description Technical features High Efficiency Motor Power Outputs Technical featuresLow Power Consumption Optical Encoder Inputs AX2850 only Data Logging Capabilities Advanced Safety FeaturesSturdy and Compact Mechanical Design Power Connections Connecting Power and Motors to the ControllerPower Connections Controller Power Connecting Power and Motors to the Controller Controller Power Mended Off Configuration Controller Powering Schemes Powering the Controller from a single Battery Powering the Controller Using a Main and Backup Battery Controller Powering Schemes Connecting the Motors Powering the AX2550 with a Main and Backup Supply Single Channel Operation Converting the AX2550 to Single Channel Power Fuses MCU Power Regeneration Considerations Wire Length LimitsElectrical Noise Reduction Techniques Overvoltage Protection Undervoltage Protection Using the Controller with a Power Supply Using the Controller with a Power Supply Connecting Power and Motors to the Controller Basic Operation Input Command ModesGeneral Operation Basic Operation Open Loop, Mixed Speed Control Selecting the Motor Control ModesOpen Loop, Separate Speed Control General Operation Close Loop Position Control Closed Loop Speed ControlSelecting the Motor Control Modes Temperature-Based Current Limitation User Selected Current Limit SettingsSetting Continuous High Amps Temperature Max Amps Battery Current vs. Motor CurrentBattery Current vs. Motor Current Motor Current = Battery Current / PWM ratio Regeneration Current Limiting Off Programmable Acceleration Programmable Acceleration Command Control Curves Left / Right Tuning Adjustment Left / Right Tuning AdjustmentExponentiation Parameter Value Selected Curve Parameter Value Speed Adjustment Activating Brake Release or Separate Motor Excitation Emergency Shut Down Using Controller SwitchesEmergency Stop using External Switch Activating Brake Release or Separate Motor Excitation Using the Inputs to Activate the Buffered Output Special Use of Accessory Digital InputsInverted Operation Self-Test Mode Self-Test Mode Important Warning AX2550 Connections Connecting Sensors and Actuators to Input/OutputsAX2550 Connections Connecting Sensors and Actuators to Input/Outputs AX2550’s Inputs and Outputs Signal Type Use ActivatedAX2550’s Inputs and Outputs Pin1 List and Pin Assignment Connecting devices to Output C Connecting devices to Output C Connecting Switches or Devices to Input E Connecting Switches or Devices to Input F Connecting Switches or Devices to Input F Connecting Switches or Devices to EStop/Invert Input Show how to wire the switch to this input Analog Inputs Connecting Position Potentiometers to Analog InputsAnalog Inputs Connecting Tachometer to Analog Inputs Ana Ana2 Operating Mode Pin Connecting Tachometer to Analog Inputs Operating Mode Ana 1 p11 Ana2 p10 Ana 3 p12 Ana 4 p8 Temp oC Connecting External Thermistor to Analog InputsResistance kOhm Using the Analog Inputs to Monitor External Voltages Using the Analog Inputs to Monitor External VoltagesConnecting User Devices to Analog Inputs Measured volts = controller reading + 128 * 0.255 Internal Heatsink Temperature Sensors Internal Voltage Monitoring Sensors Temperature Conversion C Source Code Temperature Conversion C Source Code Connecting Sensors and Actuators to Input/Outputs Optical Incremental Encoders Overview Installing Connecting Using Encoder ModuleOptical Incremental Encoders Overview Installing, Connecting and Using the Encoder Mod Recommended Encoder Types Installing the Encoder Module Installing the Encoder ModulePulse Frequency in Hz = RPM / 60 * PPR Position of Encoder Module on Controller’s main board Connecting the Encoder Connecting the EncoderPin Name Cable Color Cable Length and Noise Considerations Voltage Levels, Thresholds and Limit SwitchesMotor Encoder Polarity Matching Voltage Levels, Thresholds and Limit Switches Wiring Optional Limit Switches Wiring Limit Switches Without Encoders Wiring Limit Switches Without EncodersEffect of Limit Switches Motor 1 Fwd Motor 1 Rev Using the Encoder to Measure Speed Using the Encoder Module to Measure DistanceMotor Fwd Motor Rev Using the Encoder to Track Position Using the Encoder to Track Position RS232 Communication with the Encoder Module Distance = Destination Counter value / Divider Encoder Testing and Setting Using the PC Utility Encoder Testing and Setting Using the PC Utility Installing, Connecting and Using the Encoder Mod Selecting the Position Mode Closed Loop Position ModeMode Description Mode Description Position Sensor Selection Closed Loop Position ModeSensor Mounting Feedback Potentiometer wiring in RC or RS232 Mode Feedback Potentiometer wiringFeedback Potentiometer wiring Feedback Potentiometer wiring in Analog Mode Pot wiring for RS232 or RC Command and Analog Feedback Analog Feedback on Single Channel Controllers Analog Feedback on Single Channel Controllers Using Optical Encoders in Position Mode Sensor and Motor Polarity Adding Safety Limit Switches Encoder Error Detection and ProtectionEncoder Error Detection and Protection SW1 SW2 Using Current Limiting as Protection Using Current Limiting as ProtectionControl Loop Description PID tuning in Position Mode PID tuning in Position Mode Closed Loop Position Mode Closed Loop Speed Mode Selecting the Speed Mode Closed Loop Speed Mode Using Optical Encoder for Speed Feedback AX2850 onlyTachometer wiring Tachometer or Encoder Mounting Speed Sensor and Motor Polarity Speed Sensor and Motor Polarity Adjust Offset and Max Speed PID algorithm used in Speed mode Control Loop Description PID tuning in Speed Mode Use of the LED Display Normal Fault Condition LED MessagesUse of the LED Display Motor Direction Status Normal and Fault Condition LED MessagesPossible Display Motor Comment No Control Fault MessagesFault Messages Rapidly Flashing Permanent Faults Temporary FaultsSelf-Test Display = Software version 1.9b Self-Test Display 108 C radio control mode C Operation Pin Input or Number Output Signal Description Selecting the R/C Input ModeConnector I/O Pin Assignment R/C Mode Operation Supplied Cable Description Input Circuit DescriptionInput Circuit Description Powering the Radio from the controller RC Cable wiring diagram Powering the Radio from the controller Wiring for powering R/C radio from controller Connecting to a Separately Powered Radio Operating the Controller in R/C mode Reception Watchdog Reception Watchdog Important Notice about PCM Radios Transmitter/Receiver Quality Considerations Joystick Deadband Programming Joystick Deadband Programming Left/Right Tuning Adjustment Joystick Calibration Automatic Joystick Calibration Automatic Joystick Calibration Activating the Accessory Outputs Data Logging in R/C Mode Data Logging in R/C Mode 122 Analog Control and Operation Pin Input or Number Signal Output Description Connector I/O Pin Assignment Analog ModeAnalog Control and Operation Connecting a Potentiometer Connecting to a Voltage SourceConnecting to a Voltage Source Selecting the Potentiometer Value = U/R = 5V / 1000 Ohms = 0.005A = 5mA Analog Deadband Adjustment Analog Deadband Adjustment Under Voltage Safety Power-On SafetyData Logging in Analog Mode Data Logging in Analog Mode Modified Analog cable with RS232 output data logging for PC 130 Use and benefits of RS232 Serial RS-232 Controls OperationUse and benefits of RS232 Connector I/O Pin Assignment RS232 Mode Serial RS-232 Controls and Operation Cable configuration Cable configurationExtending the RS232 Cable Bits/s, 7-bit data, 1 Start bit, 1 Stop bit, Even Parity Communication SettingsEstablishing Manual Communication with a PC Establishing Manual Communication with a PC RS232 Communication with the Encoder ModuleRoboteq v1.9b 06/01/07 s Entering RS232 from R/C or Analog mode Data Logging String in R/C or Analog mode Commands Acknowledge and Error Messages Command Type Description Controller Commands and QueriesRS-232 Watchdog Set Accessory Output Set Motor Command ValueController Commands and Queries Query Analog Inputs Query Power Applied to MotorsQuery Amps from Battery to each Motor Channel Syntax ?r or ?R Query Heatsink TemperaturesQuery Battery Voltages ?m or ?M Reset Controller Query Digital Inputs Apply Parameter Changes Accessing & Changing Configuration Parameter in FlashAccessing & Changing Configuration Parameter in Flash Read parameter Flash Configuration Parameters List Location Description Active after Address Access Read/Write Effective After Reset Input Control ModeMotor Control Mode Value Mode See pages Amps Limit Bit Definition See pages Input Switches Function Acceleration RC Joystick or Analog Deadband Address Channel Access Read/Write Effective InstantlyExponentiation on Channel 1 and Channel Left/Right Adjust Default Encoder Time Base 1 Default PID Gains Default Encoder Distance DividerJoystick Min, Max and Center Values Reading & Changing Operating Parameters at Runtime Location Function Bit Function Operating Modes RegistersRead/Change PID Values Address 82 P1 83 I1 84 D1 85 P2 PWM Frequency Register Controller Status Register Current Amps Limit Registers Controller Identification RegisterBit Model or Function Set/Reset Encoder Counters and Destination Registers RS232 Encoder Command SetRead Encoder Counter Read Speed Or !Q n Read Distance Read Encoder Limit Switch StatusRead Speed/Distance Read / Modify Encoder Module Registers and Parameters Switch ValueDD= parameter value Address Parameter Description Size Access Encoder Hardware ID code Switch StatusRegister Description Speed or Distance 1 or Destination Register 1 Counter Read/Write MailboxCounter 1 Register Description Time Base 1 Distance 1Speed 1 Encoder Threshold Counter Read Data Format Counter Read Data FormatDecimal Bit Hex Controller Output 164 Automatic Switching from RS232 to RC Mode Automatic Switching from RS232 to RC Mode Analog and R/C Modes Data Logging String Format Data Logging Cables Decimal to Hexadecimal Conversion Table Decimal to Hexadecimal Conversion TableDec Hex UDec Hex AX2550 Motor Controller User’s Manual 169 170 Programming using built-in Switches and Display Configuring Controller using SwitchesProgramming Methods Entering Programming Mode Configuring the Controller using the Switches Changing parameters Restoring factory defaultsSpecial Case of Joystick Calibration Exiting the Parameter Setting Mode Programmable Parameters List Programmable Parameters List Order Letter Description Possible Values default PagesSee 176 Downloading and Installing the Utility Using the Roborun Configuration UtilitySystem Requirements Connecting the Controller to the PC Using the Roborun Configuration Utility Roborun Frame, Tab and Menu Descriptions Roborun Frame, Tab and Menu Descriptions View Controller Connector Pinout Parameter Selection and Setting and Special FunctionsFile and Program Management Commands Getting On-Screen Help Loading, Changing Controller Parameters Control SettingsMotor Control Mode Loading, Changing Controller Parameters Power Settings Acceleration Setting Analog or R/C Specific SettingsLoading, Changing Controller Parameters Left/Right Adjust Deadband Encoder Setting and Testing Closed Loop Parameters Encoder Module Parameters Setting Encoder Setting and Testing Exercising the Motors Running the MotorsViewing Encoder Data Run/Stop Button Motor Power settingRunning the Motors Measurement Input Status and Output Setting Real-Time Strip Chart RecorderTransmit and Receive Data Logging Data to Disk Connecting a Joystick Parameter Header Data type/range Measured Parameter Command Entry Using the ConsoleUsing the Console Terminal Screen Loading and Saving Profiles to Disk Send Reset StringViewing and Logging Data in Analog and R/C Modes Keep Watchdog Alive Operating the AX2550 over a Wired or Wireless LAN Operating the AX2550 over a Wired or Wireless LAN Roboserver screenshot when idle Updating the Controller’s Software Updating the Encoder Software Creating Customized Object FilesCreating Customized Object Files Objectmaker creates controller firmware with custom defaults Mechanical Dimensions Mechanical SpecificationsMechanical Dimensions Mechanical Specifications Mounting Considerations Thermal Considerations Wire DimensionsWire Gauge Outside Diameter Color Length Attaching the Controller Directly to a Chassis Weight