Space Vehicle Control Systems Know the elements of a control system. Know the difference between open-loop and closed-loop control systems. Know the steps in the control process

Space Control Systems Describe the elements of a control system. Explain the difference between open-loop and closed-loop control systems. Describe the steps in the control process. Describe the functions of control systems

The Systems-Engineering Process

The Design Process The spacecraft design process shows how a spacecraft’s subsystems depend on each other. When we adjust the design of one subsystem, we’re likely to have to adjust some, or all, of the others.

The Design Process The Space Systems- Engineering Process

Designing Payload and Subsystems: The Spacecraft Bus The Spacecraft Bus exists solely to support the payload, with all the necessary housekeeping to keep it healthy and safe. The best way to visualize the relationship between the payload and subsystems is to picture a common, everyday, school bus.

Understanding Systems A system is any collection of things that work together to produce something. Systems have three main parts: inputs (what goes in) outputs (what comes out) some process in between that turns the inputs into outputs In electronic systems, the inputs and outputs are called signals.

Elements of Control Systems For space-vehicle applications, the mission’s success or failure depends on the output of various subsystems. So we’re most interested in a specific class of systems called control systems. Control systems are everywhere. You have used one if you’ve ever: Driven a car Turned up the thermostat on a frigid winter night

Elements of Control Systems: A Simple Heating Control System We throw logs on a fire and wait for heat to come out, warming the room. Unfortunately, this simple control system has two major drawbacks: If we put on too many logs, the room can get too hot. When we go to sleep at night, nothing ensures the house will still be warm in the morning. A system that can’t dynamically adjust the inputs based on what’s happening is an open-loop control system.

Elements of Control Systems: A Complex Control System As with any control system, we have some desired result—a house at 20° Celsius (75° Fahrenheit), which is what we tell the thermostat when we set the dial.

Elements of Control Systems: Closed-loop Control System We call this type of system a feedback-control system or a closed-loop control system because we have a thermometer (sensor), which continually measures the current temperature and feeds this information back to the thermostat (controller). With this information, the thermostat produces the correct furnace (actuator) commands to maintain the house at 70° Fahrenheit, despite environmental inputs.

Elements of Control Systems: Control System’s Tasks All control systems must do four basic tasks: Understand the system’s behavior—how the plant will react to inputs, including environmental ones, to produce outputs. This also is known as the plant model. Observe the system’s current behavior—using sensors. Decide what to do—through the controller. Do it—using actuators.

So Systems Integration is about making sure all the elements work seamlessly together…

Space Vehicle Control Systems Know the elements of a control system. Know the difference between open-loop and closed-loop control systems. Know the steps in the control process