Starting with FPGA boards

Well, when writing code for FPGA you need to think about the hardare. You describe the hardware and everything you need must be in your design. You cannot create a new "object" when the design is running. But, without knowing your algorithms, it is possible to redesign the control system. Object oriented design is not really VHDL. You might think of the entities as objects, but my advice would be to take the control algorithm with the parameters from the current design and create an VHDL equivalent. If you hope to copy and past the code, this is not the case. As for resources to read, I don't know. Maybe use your favorite web search engine and search for FPGA control system.