  In data-driven predictive cloud control tasks, the privacy of data stored and
used in cloud services could be leaked to malicious attackers or curious
eavesdroppers. Homomorphic encryption technique could be used to protect data
privacy while allowing computation. However, extra errors are introduced by the
homomorphic encryption extension to ensure the privacy-preserving properties,
and the real number truncation also brings uncertainty. Also, process and
measure noise existed in system input and output may bring disturbance. In this
work, a data-driven predictive cloud controller is developed based on
homomorphic encryption to protect the cloud data privacy. Besides, a
disturbance observer is introduced to estimate and compensate the encrypted
control signal sequence computed in the cloud. The privacy of data is
guaranteed by encryption and experiment results show the effect of our
cloud-edge cooperative design.
