Tag: Hydraulic Components

Hydraulic Components

Hydraulic component of KNR Systems Inc. (Series #4 Hydraulic Power Unit)

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4. Hydraulic Power Unit (HPU)

To operate a complete hydraulic robot consisting of actuators, valves, sensors, controllers, etc., a power source that generates and supplies hydraulic pressure is required, which is called the HPU (Hydraulic Power Unit). When used in general industries, it is efficient to install a fixed HPU in the factory and to use multiple robots by connecting hydraulic lines from a single HPU. However, if a mobile robot is to be configured, a mobile hydraulic power source is required, and a power source that increases size and efficiency for the robot’s application will have a significant impact on the robot’s usability. In general, it is common to customize and use the power source of a mobile robot for its intended use, and ensuring reliable performance also affects the performance of the entire robot.

<Mobile Hydraulic Power Unit : mHPU>

KNR Systems develops and supplies mobile hydraulic power Unit mHPU and LHPU for robot purposes among HPUs that supply hydraulic power.
The mobile hydraulic power unit is a device that supplies hydraulic pressure to power the hydraulic actuators and is compact for use in robotics and defense applications. It is compact and has sufficient flow rate and hydraulic pressure, so it can be mounted on mobile systems such as mobile robots, walking robots, and transport platforms, and has excellent functions that operate even when overturned by providing optional pressurized models.

<Hydraulic Power Unit : LHPU>

Hydraulic component of KNR Systems Inc. (Series #3 Hydraulic Controller)

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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.

<Hydraulic Actuator Controller : HAC>

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.

Hydraulic component of KNR Systems Inc. (Series #2 Servo valve)

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2. Servo valve

The servo valve is a key component in the hydraulic robot configuration that is paired with the actuator to control the flow of hydraulic pressure.
The construction excavator is designed to perform relatively easy tasks, so it consists of a simple valve that can be operated on and off control.
However, hydraulic robots require more precise control, requiring a high-performance servo valve that can control the flow rate quickly and accurately. In addition to performance, the size must be small to attach to the robot, and the price is also important because it requires as many valves as the number of actuators. The size of the servo valve used in robots is about the size of a thumb, but the price is very high and requires high manufacturing technology, so there are only a few suppliers.

hydraulic servo valve - KSV

<Servo valve : KSV-NF07>

Hydraulic servo valve technology needs to be very difficult to implement, especially small servo valves with excellent performance are limited to defense industries such as missiles and rockets, and only five or fewer companies worldwide produce most servo valves. KNR’s servo valve has more than 90% of Moog’s performance, which is a top-notch global company, and has equivalent or higher performance compared to STAR’s servo valve in the UK. It also has price competitiveness compared to its competitors by realizing low manufacturing costs with the latest special manufacturing method.