PhD modelling and control for sustainable dairy farming Wageningen University & Research, Netherlands
This PhD is part of the Synergia project . Synergia is a crossover program funded by the Netherlands Organisation for Scientific Research (NWO). Synergia contributes to the UN Sustainability Development Goals for the environment (depletion of scarce resources, global warming, acidification, eutrophication, nutrient losses, and biodiversity loss), labour (availability of skilled workers), and society (consumer/societal acceptance of novel technology and production methods). Synergia goes beyond current precision agriculture (PA) and precision livestock farming (PLF) and is developing the new concept of ‘Technology-4-Ecology-based farming’ (T4E) where biological/ecological principles in farming lead the development of new farming systems, and the required technological knowledge, principles and tools. Our multi-disciplinary team with biology, ecology, agronomy, technology and social science backgrounds, will explore how current and future farming technologies can enable and support truly ecology-based farming systems.
The aim of this PhD project is to employ the latest sensing and actuating technology in an optimal way, by designing a model-based strategy to control feed intake of cows. Controlling feed intake on a herd level is too coarse; there is a lot of variation between cow feed intake response. For example, some cows are lactating, and others not. The feed intake should be tailored to serve the needs each cow individually: maintaining a healthy internal energy balance, while minimizing harmful emissions of phosphate, nitrogen, and methane.
The research challenges
The development of a model based controller raises the following scientific challenges, that will form the backbone of your research.
The first challenge is to select a mechanistic energy model, and transform it into an input-state-output form that is suitable for control design. The next challenge is to extend the model with some chemical/physiological processes that describe excretion of phosphate, nitrogen, and methane. Mechanistic models that describe the internal energy balance of cows have been developed. Such models describe how food of different compositions are processed into energy, and how this energy is allocated to milk production, gestation, body mass, fat storage, and resilience. The selected model can be trained via data sets made available within our consortium.
Thereafter, the model parameters can be tuned to enable controller design for individual cows, for example via a parameter estimation algorithm.
Finally, a controller can be designed that provides reliable and automated advice on feed intake, even under uncertainty in model predictions or circumstances, for example a robust or stochastic controller. This is a basic plan. There is flexibility to develop your own research objectives and methods.
Within our research consortium there are already models, data and knowledge on cow physiology, and feed intake response, which will be expanded throughout the project. Also several companies are involved that represent the state of the art in industry. This PhD project provides a unique opportunity for developing a novel control design that is tailored to the needs of the modern farming industry, and embedded in a solid scientific background.