Biomimetic robot helps milk cows

Faced with automating the procedure of milking cows, IceRobotics has developed a system that provides three-dimensional coordinate data on the position of the cow’s teats in real time.

The first fully automated robotic milking stall was introduced in the Netherlands in 1992. These robot systems enable ‘self-service milking’ by the cow, whereby the milking robot is accessible by the cow without the need for the farmer to be present.

Such use of robotics promises increased milk yields, reduced labour requirements and numerous cow welfare benefits. This new approach to dairy farming has already been proven to increase the cow’s milk yield by as much as 20% as a result of milking 3 or 4 times each day instead of the conventional twice a day approach. Many in the industry are now predicting a dramatic move to robotics on dairy farms over the forthcoming decade. Already, nearly 2,000 farms worldwide have installed a robot milking system.

Existing milking robots use laser-scanning technology to locate the cow’s teats and then guide a conventional robot mechanism to attach automated milking cups to each of the four teats in turn. However, the dairy parlour setting starkly contrasts the clean and controlled environment of the manufacturing plants in which conventional robot systems have evolved. Such robot technology has a difficult transition into dairy farm environments because of vulnerability to dirt and fluids, the need for expensive adaptation to minimise injury risks to the animal, the requirement for regular ongoing maintenance and the low price demanded by farmers. Now, biomimetic robotics is offering an alternative solution.

Taking inspiration from the natural world, biomimetic engineering seeks to mimic the sensory and biological systems found in biology. The combination of advanced sensory perception with organic motion and dexterity enables the development of robots that can operate in complex ‘real world’ environments. IceRobotics is an Edinburgh based company that is applying this new biomimetic paradigm to help increase the range of markets accessible to the robotics industry. IceRobotics has now been approached by the milking equipment industry to use its biomimetic expertise to develop a new generation of automated milking robots that rise to the challenges posed by the dairy farm environment.

In applying the biomimetic paradigm to the teat location problem, the IceRobotics solution uses stereo vision technology to provide three-dimensional coordinate data on the position of cow teats in real time.

Dr. Oliver Lewis, Project Manager at IceRobotics, explains ‘using laser technology to detect cow teats is like using a sledgehammer to crack a nut. The teat cups are attached using a suction mechanism, and so when positioning cups, the robot only requires millimetre accuracy – rather than the sub micron accuracy many laser systems can achieve. At IceRobotics we have developed a stereo vision system using a pair of calibrated low cost CMOS image sensors to locate and track natural point targets. We have now adapted this technology to track cow teats to millimetre accuracy at 10Hz.’

Dr. Lewis sees further possibilities for the cow teat sensor, ‘One disadvantage of fully automated milking is that contact between the farmer and the cow is reduced, making it harder to pick up and treat sick animals at an early stage. By putting cameras into the system, we open up possibilities for automatic visual inspection for cuts and malformations, this could be a key tool in supporting animal health and welfare.’

IceRobotics has also developed the use of flexible actuators as an alternative to the conventional kinematic chain approach to robotics. These actuators produce movements by bending an elastic continuum without the need for additional skeletal structure. Differential air pressure between three parallel flexible actuators, causes bending in any plane perpendicular to the longitudinal axis of the device.

The greater the pressure differential, the larger the deflection of the free end. The original arm, made from convoluted grey polymer tubing, became known as the ‘elephants trunk’. This technology was originally developed at Heriot-Watt University by robotics technologist Dr. Bruce Davies, founder of IceRobotics. Operating in conjunction with the CMOS sensor technology, IceRobotics is now developing the Mimetix actuator for robot systems. This actuator will enable the continuing evolution of the early designs of milking robot into advanced biomimetic service robot solutions which can reliably perform a wide range of tasks on the dairy farm, including teat cleaning prior to milking, the placing and removal of milk cups, and post-milking teat disinfection. Furthermore, biomimetic components will be replaceable at very low cost, introducing the potential for disposable robot arms and end-effectors in the interests of animal health and food hygiene.

The use of biomimetics on dairy farms heralds a new era not only in dairy farming but also in the robotics industry at large. Biomimetic technology offers the potential to greatly extend the current boundaries of robotics beyond traditional industrial environments. With capability for direct and safe interaction with people and animals, a new breed of robot is now on the horizon.

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