Energy management for cleaning vehicles
A major challenge is to cope with the dirt in megacities. For this purpose, there is municipal technology such as sweepers that absorb large amounts of dirt or absorb impurities easily even on blocked areas or in narrow streets. The aim is to clean efficiently in order to reduce the impact on the environment. The sweepers used on roads, pavements and in public areas usually work with diesel engines. In Berlin alone (capital of Germany), all cleaning vehicles had covered a distance of 1.5 million kilometres in 2014. Alternative drive options are therefore a sensible starting point towards greater sustainability and environmental protection. For this, Kärcher, in cooperation in with the Baden-Württemberg Ministry of Economic Affairs started a pilot project for the development of sweepers with electric drive. Under the pilot project Five vehicles are currently being tested and the application profiles as well as the effects on the environment are being analysed. “The use of electric drives is only one aspect,” says Peter Stanzel, Head of Development Municipal Cleaning at Kärcher. “In future, builder’s yards on which vehicles are parked would be able to generate electricity from environmentally-friendly sources, i.e. photovoltaic systems, combined heat and power plants or biogas. The vehicle batteries are charged and used either for operational purposes or the vehicles are connected to the mains and serve as a buffer in times of higher consumption.” This scenario shows that smart energy management across different areas of the infrastructure, in this case electricity generation, storage and cleaning, is crucial for the future alignment of smart cities.
Focus on emissions – reducing fine dust
Megacities such a Peking demonstrate that air pollution is mainly responsible for affecting the quality of life. On the one hand, the drive issue plays a role, which is why the focus is increasingly on electric motors. On the other hand, for large sweepers, research is being carried out to optimise the performance of the utilised filter to reduce the occurrence of fine dust.
Philipp Röhrle explains the basic principle: “There are two different filter technologies, depending on the function of the machines. In the case of mechanical waste pick up, we work with mechanical filtration which, for example, is relevant in cold regions – since water would freeze immediately. In hot, dry regions, waste pick up using a vacuum sweeper takes place by so-called separating filtration with water.” In both cases, the utilised filters up to 2.5 μ must be capable of retaining the fine dust. This is already possible for small machines; there is currently a space problem with larger machines, which is currently in the process of being resolved.
Using data for cleaning on demand
Another important aspect is the efficient control of cleaning activities for maximum utilisation of the vehicle fleet. Dr. Friedrich Völker, responsible for Digital Products at Kärcher, describes the latest product in his department: “With Kärcher Fleet, an operator who has 50 machines in use throughout Germany, for example, can keep constant track of the location of his machines, ascertain whether they are functional, monitor the state of charge of the battery and determine if they are working to full capacity.” For this purpose, Kärcher has fitted its vehicles with a telematics unit including GPS and SIM card, which is connected to the machine control. “If required, the data can be sent in realtime to the smartphone of the person responsible; with the customer’s consent, we can also access this data and, e.g. automatically initiate the maintenance of a machine, if necessary.”
Kärcher Fleet is already in use today, however such systems also offer potential with regard to new business models. “It is conceivable that a machine operator will no longer need a machine fleet, but only pay for the square metres cleaned using our machines based on a rental agreement. Guarantee, service and cleaning agents included. For the operator, this would be a 100 per cent safe calculation, as no investment is necessary. The utilisation of our machines would also be able to be controlled, as they are not stationed in one place, but operate wherever they are needed nationwide.”
Apart from nationwide utilisation of cleaning machines, demandorientated cleaning control is a topic for the future. GPS monitoring is already in use in the control centre. However, a basic plan is available that tends to make the system inflexible. This means that cleaning takes place time and again in areas that are clean and not in other areas that need cleaning. The future vision is to use data to enable cleaning on demand. Dr. Völker explains: “This is comparable with route planning using Google Maps: smartphones always send the location and speed of their users – if the function is not deactivated. Google Maps uses these movement profiles to ascertain the traffic situation in order to suggest alternative routes as required.”
In essence, it is about establishing an integrated concept and collecting and interpreting data intelligently. In future, networking and automation could go much further than previously imagined. “Here, it is worthwhile looking at the Smart Home concept,” says Dr. Völker. “There are research projects where the heating of buildings is coupled with sensors that measure the oxygen content in the air. This decreases when people are in the room – and the heating turns on. Future cleaning concepts could be orientated on such scenarios.”
It is conceivable that the same system could be used for cleaning roads, coupled with sensors in traffic lights that monitor the volume of traffic or weather sensors, which provide feedback on specific conditions such as slush. In order to have stringent procedures in place, it is also important to plan the infrastructure of modern cities differently. Philipp Röhrle, Product Manager Municipal Sweepers at Kärcher, explains: “Up to now, numerous cities have had a centralised structure, i.e. a sweeper covers a distance of 15 kilometres to reach the location of use. If there were decentralised routes in combination with demandorientated cleaning models, far more efficiency could be achieved in route management and energy consumption.”