Servo Drive Aces Military And Harsh Industry Environments
March 1, 2008
Related To: Copley Controls Corp.
Copley Controls has developed a hardened version of the versatile panel-mounting Accelnet servo drive to meet both military and extreme industrial environments. The drive’s extended temperature, humidity, vibration and shock ranges provide added security in non-extreme applications. Designated Series R20, the hardened drives provide networking and stand-alone motion control for brush and brushless motors, and direct drive linear motors and actuators. R20 drives deliver up to 3.200 kW peak power and are available for operating voltages: 55V, 90V and 180V, and deliver 9A, 18A and 36A peak currents.R20 drives operate in stand alone and networked operating modes. Their very wide span of Command, Encoder Feedback and Communications interfaces allow users to put a single drive model to work in widely differing motion control systems. Control modes include indexing, point-to-point, PVT (position, velocity, and torque control), as well as electronic camming and gearing. Specific command interfaces include CAN/open, DeviceNet, ASC11/Discrete I/O, Stepper, ±10V position/velocity/torque, and PWM velocity/torque command. This communications flexibility highlights the drive’s compatibility with so many different motion control architectures. Copley’s CME 2™ setup software enables drive users to automate otherwise time-consuming system setup and commissioning functions. The software provides auto tuning of the amplifier’s current loop, and auto phasing of Hall sensors for both rotary and linear motors & actuators. With setup and tuning completed, the user stores software settings in the drive’s non-volatile flash memory.Copley has developed extensive libraries of motion control software (Copley Motion Libraries) and software COM objects, to make system development fast and simple. The development of low level code to control a CANopen network of intelligent drives is eliminated. All network housekeeping is taken care of automatically by a few simple commands linked into the user’s Visual Basic, Labview or C++ application program. Dynamic SpecificationsThe R20 drives use the advanced carrier cancellation modulation (CCM) for zero crossing linearity and low ripple current. Ripple frequency is 30 kHz. Current loop bandwidth is 2.5 kHz. The amplifier provides 15 kHz current loop update rate (67 µs) and 3 kHz (333 µs) position and velocity loop update rate. Mechanical Design, ProtectionR20 drives are housed in shielded enclosures measuring 6.6” x 3.9” x 1.2”. The drives are protected against over-current, over-temperature, and incorrect operating voltages. They are further protected from short circuits between outputs, from output to ground, against over-current, over-temperature, and against incorrect operating voltages. In addition, protection circuits guard against loss of signal from either the encoder or the motor’s Hall sensors. Built-in computation algorithms monitor the I2•T heating effect of load current, enable a motor to run safely at its outer performance envelope. ApplicationsHardening the Accelnet R20 drive for COTS military, aviation and marine applications also creates a motion control solution for extreme industrial environments. R20 drives handle the high temperatures of solar energy collection, food manufacturing, oil refinery and steel foundry uses, plus the opposite extremes of arctic satellite tracking, industrial cold rooms, and refrigerated meat packing operations. Model R20 also qualifies for oil rig use, ship-board cargo handling equipment, and off-road vehicles, where resistance to shock and vibration are critical.