Keeping things rolling: Saarbrücken engineers develop sensor-free smart wheel technology
At this year’s Hannover Messe, Matthias Nienhaus and his research group from Saarland University will be exhibiting a technology that not only allows wheels to ‘know’ when and how to rotate, but also enables them to work together in interactive teams. The new technology can be used wherever there is a need for additional support when pulling, pushing or driving a system that uses wheels. Potential applications range from mobility aids, such as wheeled walkers and wheelchairs, to sack trucks, wheelbarrows and shopping trolleys.
Simply monitoring the data generated when the motors inside the wheels rotate, allows the motors and hence the wheels to be controlled without the need for any additional sensors.
The team is in Hannover to look for partners interested in using this new technology in practical wheel-based applications.
The team of engineers will be showcasing their new technology at Hannover Messe from the 23rd to the 27th of April at the Saarland Research and Innovation Stand (Hall 2, Stand B46).
Anyone who has ever tried to manoeuvre a washing machine on a sack truck will know the feeling of wishing for an invisible force that springs into action whenever the load threatens to become unbalanced. A bit here, a bit there, just enough additional support to keep everything level so that you can push and pull the load to its destination without worrying about it tipping over. Wheels equipped with novel drive technology developed at Saarland University offer exactly this capability. The wheels recognize immediately whenever there is increased or reduced loading on the right or left hand side of the sack truck and they are aware of any changes in their own position. And this is achieved without the need for any additional sensors. Simply by monitoring the data generated by small electric motors within the rotating wheels, the system knows the positions of the wheels and the forces applied by the drive motors. But the technology is not restricted to sack trucks; it can be used in any application involving motor-driven wheels. ‘At Hannover Messe, we’re looking for project partners who can work with us to develop these wheels for a range of applications,’ says Professor Matthias Nienhaus.
The focus of the research work conducted by Nienhaus – a drive systems specialist at Saarland University – is smart motors that generate operational data without the need for additional sensors. ‘We essentially turn the motor itself into a sensor, effectively creating a new category of sensor. It’s a very cost-effective but powerful technique,’ explains Nienhaus. ‘We are currently carrying out multiple research projects in which we examine how we can extract the greatest possible quantity of data from electric motors that we then use to control the drives more efficiently. But we also use the data to monitor whether the motor is operating properly or whether there are indications of faults or signs of wear,’ he adds. For example, the research engineers observe how the electromagnetic field is distributed at particular locations within the motor and how this field changes while the motor is running. A patent application has been filed to protect the novel procedures that make the data even more reliable by computationally filtering out unwanted artefacts and noise.
At Hanover Messe, the team will be demonstrating their system using an installation equipped with multiple wheels. ‘If the new technology is introduced into multi-wheeled applications, we have the ability to control wheels individually and can therefore have as many wheels working together as we like,’ explains Nienhaus. This is all done automatically using a tiny microcontroller that gathers the data from the individual drive motors and then calculates when and with what power a particular motor needs to switch on.
The engineers have carefully studied how the measured data correlates with specific motor states and how a specific measured quantity changes when a wheel rotates. The more data they collect on the motor that drives the wheel, the more precisely they can control the motor and hence the wheel. The research team analyses the huge amount of motor data in order to identify signal patterns that can be used to infer knowledge about the current state of the motor or to flag up changes. The team is developing mathematical models that simulate the various motor states. If the signals coming from the wheels change, the control system can identify the underlying change in the motor’s state and can almost immediately respond with appropriately programmed commands. When a number of these ‘sentient’ motors are connected via a databus system, the wheels can work together in one integrated network.
Prof. Dr. Matthias Nienhaus (Laboratory of Actuation Technology, Saarland University, Saarbrücken, Germany) Tel.: +49 (0)681 302-71681; Email: firstname.lastname@example.org
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German Version of the Press Release:
The Saarland Research and Innovation Stand is organized by Saarland University’s Contact Centre for Technology Transfer (KWT). KWT is the central point of contact for companies interested in exploring opportunities for cooperation and collaboration with researchers at Saarland University.