A particulate estimation system is configured for estimating a mass of particulate matter accumulated in a particulate filter of an exhaust system. The system includes a memory device, an interface, and a controller. The memory device stores a plurality of modules. Each of the plurality of modules is configured to uniquely estimate an amount of the particulate matter accumulated within the particulate filter over a period of time. The interface receives a plurality of input signals. The plurality of input signals correspond to a plurality of modules that are stored in the memory device. The controller derives a hybrid model based on the input signals. The hybrid model is configured to provide an output that is an estimation of the amount of particulate matter accumulated within the particulate filter over the period of time as a function of the plurality of input signals.