Massflow and vent temperature management for zonal air temperature control and disturbance rejection in vehicle cabins

Abstract

Cars are commonly sold with multi zone air conditioning systems. These systems rely on various cooling and heating devices to achieve desired temperatures in multiple zones of a vehicle cabin. Even though various approaches have been presented, the task of temperature tracking and disturbance rejection remains challenging. A control approach is presented which allows for simultaneous air outlet temperature and mass flow management to control the cabin temperature in multiple vehicle zones. Based on recently presented grey-box models of the vehicle vent systems, as well as the cabin itself, a real-time mass flow optimization scheme is developed. The scheme is compatible with both accurate disturbance rejecting temperature control and application restrictions. Based on this mass flow controller, a previously presented model predictive outlet temperature controller is further researched to accurately track temperature references in multiple vehicle zones. Accurate tracking and fast disturbance rejection is experimentally validated with a test vehicle. Step response times between 27 s and 193 s were consistently achieved based on step height and massflow controller setting. Rejection of large disturbances such as opening windows is furthermore demonstrated for the two zone control case.