Reaction wheel

When moving in orbit, many spacecraft require precise orientation with certain faces in the right direction - relative to Earth, the Sun, stars, or otherwise. For example, to aim the Earth observation camera or solar panels at the Sun. On small spacecraft, to maintain the desired orientation of the spacecraft in space relative to the center of mass, reaction wheels are often used.

The Reaction wheel is an electromechanical device that consists of an electric motor with a wheel attached to its axis of rotation. The motor rotates, either accelerating or decelerating, and according to the law of conservation of angular momentum, it rotates faster or slower than the spacecraft itself. Since there are no external forces in space and the amount of motion cannot change, rotating the reaction wheel clockwise leads to the entire spacecraft rotating counterclockwise. By controlling the motor and the rotation of the reaction wheel, we can control the movement around the center of mass (essentially, the rotation) of the entire spacecraft.

In our model of the Orbix constructor, and therefore of the reaction wheel, free rotation is only possible around one axis - the vertical one. Therefore, only one orientation reaction wheel is installed on the "space probe."

The following functions (in the C++ language) are used to work with the reaction wheel:

int32_t motor_set_speed(uint16_t num,int16_t RPM,int16_t *confirm); 

Allows setting the speed of the reaction wheel, returns the code LSS_OK and the value of confirm equal to the required RPM in case of success. However, the actual acceleration of the reaction wheel to the required speed may take a considerable amount of time.

The following function allows to request the current speed of the reaction wheel:

int32_t motor_request_speed(uint16_t num,int16_t *pRPM);