The use of a digital controller in the loading system of the test bench to improve the accuracy of simulating the modes of oil pumping unitsTimur Petrov, Vladimir Kornilov, Alfred Safin, Nikita Kuvshinov, Alexey Tsvetkov and Ramil GibadullinE3S Web Conf., 220 (2020) 01072DOI: https://doi.org/10.1051/e3sconf/202022001072