Comparative Overview of Motor Controls

Microcontrollers, Field Programmable Gate Arrays (FPGA), and Application-Specific Integrated Circuits (ASIC) are three types of technology used in motor controllers for space applications. At a minimum, the command interfaces of these controllers need to communicate the simple commands to move a motor such as when to move and what direction to go. However, each technology has unique nuances that separate one another.

The Choices

ASICs are designed for specific tasks and require less support circuitry. They have established test and verification programs, making them reliable. However, developing an ASIC is expensive and involves designing, laying out, and fabricating a custom integrated circuit. ASICs have limited flexibility but can be cost-effective if existing designs meet the requirements.

FPGAs are commonly used in space applications for motor controllers. They are very flexible and can be configured for different commands and control schemes. FPGAs come in different sizes and with different features, making them suitable for both simple and complex designs. Some designs can start running almost immediately after being powered up. FPGAs can support complex interfaces, control multiple motors, and run multiple control loops. They offer high performance and customization but are more expensive, more challenging to update, and consume more power compared to microcontrollers.

Microcontrollers are like minicomputers on a single chip. They come with built-in bootloaders, RAM, non-volatile memory, oscillators, and many hardware peripherals. They provide communication links, interfaces for external memory, and converters to change signals from analog to digital and vice versa. Microcontrollers allow new software to be loaded without needing to access the hardware directly. They can control motors and adjust their performance while in space. Microcontrollers are easier and quicker to integrate for standard interfaces and cost less.

Advancing Motor Control Solutions for Space Applications

The space industry has trusted Moog as a reliable source for solutions that work every time. For microcontrollers, Moog offers a versatile and cost-effective alternative to FPGAs in designs that control one or two motors per board. They simplify the integration of command interfaces and feedback systems, making it easier to develop control loops that align with simulations. When working with designs that need two or more motors, microcontrollers can still be cost efficient by adding more boards to a system. Software development can start on a Microchip Development Board, migrate to a pin for pin compatible Software Development Unit and then directly transfer to engineering Model and Flight Hardware. This makes microcontrollers an attractive option for multiple motor controllers linked to a Single Board Computer to achieve a comprehensive movement solution. As spacecraft missions become more complex, the number of subsystems and components that need to be controlled and monitored increases. Microcontrollers meet those requirements by providing next generation motor controllers in spacecraft.