Anna Konda – The fire fighting snake robot
Anna Konda was developed in order to demonstrate the SnakeFighter concept. The robot is to our knowledge the biggest and strongest snake robot in the world and also the first water hydraulic snake robot ever constructed.
Length: 3 m
Weight: 75 kg
Number of DOFs: 20
Angular flexion in each joint: +/- 33 degrees
Actuators: Water hydraulic cylinders
Max system pressure: 100 bar (1450 PSI)
Max torque (at 100 bar): 300 Nm
Water hydraulic cylinders
The joints in Anna Konda are moved by a total of 20 water hydraulic cylinders. The cylinders were custom-built in order to make them as compact as possible. They can handle a system pressure of 100 bar (1450 PSI).
Water hydraulic valves
Each joint module in Anna Konda is equipped with two water hydraulic valves in order to control the pressure applied to the two cylinders in the joint module. The limited availability of compact water hydraulic valves in the market today forced us to custom-build these valves. The two valves for each joint module are integrated in a single valve block in order to save space.
Embedded control system
Microcontrollers (AVR ATmega128) are used to control the motion of the joints of Anna Konda. A communication bus through the robot allows for communication between the microcontrollers and a dedicated controller in the head of the robot (the brain). The brain can communicate with an external computer through a wireless connection based on Bluetooth. This allows the robot to be remotely controlled by an operator.
Anna Konda has a steel skeleton. The parts were designed based on strength calculations that were performed to ensure that the hydraulic actuation forces would not destroy the robot.
Assembled joint module
The figure on the left shows a joint module assembled from the mechanical components.
The robot is covered by skin plates in order to give the robot a smooth exterior surface and to protect internal components. Contact force sensors are mounted beneath the skin plates to allow the robot to sense external contact forces along the snake body.
Anna Konda is equipped with nozzles in the front that enable the robot to spray water and thereby demonstrate the fire fighting application.
Contact person at SINTEF Applied Cybernetics: Aksel Transeth