2. Hydraulic Controller
The controller is a key component that controls the required movement by reading movement from the hydraulic actuator into the sensor. Unlike conventional industrial hydraulic controllers, robot controllers typically have distributed controls that perform control per axis, as they are small and have various controls. It is configured by connecting the Axis controller, which controls each axis, and the Robot controller, which creates and controls the completed robot-type motion.
Unlike motor controllers, hydraulic sub-controllers control the flow of hydraulic pressure without using high voltage and current, so they can be directly embedded into or attached to the actuator and require performance and functionality similar to a motor-type robot controller. Even if it is not a finished multi-DOF robot, it is often used in one to two axis or independent actuator configurations, so there is a high demand for the system to be configured with only sub-controllers, hydraulic actuators and valves.
The subcontroller responsible for controlling each axis of the hydraulic robot must be implemented small enough to be located close to the actuator, incorporate a variety of control algorithms, and be able to be connected to the outside world through major communications. KNR Systems’ HAC series standard controller is currently developed up to version 2.2 and consists of a high-performance Cortex M4 chip that can be controlled internally at up to 5 kHz intervals and supports control communications including CAN/SPI/SSI/Analog. The internal controller provides a default selection of location, force, and compliance controls, and provides an option board for more than five types of feedback sensors. The HAC Pro 1.0, which is in the final stage of development, is being developed for the sole purpose of actuators and is designed to support a range of the latest real-time high-speed communications, including faster operations such as MCU and CANFD, EtherCAT, and Pronfinet.
KNR Systems is a high-performance eight-axis multi-axis controller using TMS320 DSP, which provides Ethernet communication, and develops and sells LCUs as a high-level robot controller. This high-performance controller is small enough to be attached to the robot arm, but it has the ability to compute more than 1 kHz of robot mechanics every time.