Our flight computers store their flight data in a text file every few milliseconds. When this occurs, a new line is created inside this file, which accumulates to over 85,000 lines over the flight duration. Analyzing this data by hand proved daunting and impractical. Therefore, we developed a GUI in July 2020 to optimize this process. This GUI can either represent life-transmitted data in real-time during a flight or help to analyze the data of past flights. When simulating past flights, the program reads out the text file and represents all flight data through animations, graphs, and text fields.

Note: As the visualization software was created back in 2020, the software still uses the old JM space logo.

JM Eagle Control - Mode Selection Window

When starting the application, users can choose from three modes:

Launch Mode: capable of remotely initiating the launch of the Buffalo rocket. For this purpose, an additional transmitter board is connected, through which the laptop can communicate with the launchpad computer.

Reconstruct Mode: designed for reviewing past flights.

Close/Save Mode: used to save flight data generated during “Launch Mode” to an SD card.

Launch Mode

After selecting the launch mode, a pop-up field appears in which the user enters the name of the flight file. If the laptop is able to connect with the transmitter PCB, the flight file is generated, and the launch application appears.

Within the GUI, a start button can be activated. However, a security code must be entered before initiating the countdown sequence to prevent unauthorized access. After successfully entering the code, the countdown sequence begins, the back button disappears, and the start button is replaced by a stop button to be able to cancel the countdown.

An animation of an LED simulates the built-in RGB LED of the Buffalo flight computer. Below this animation, the countdown time is displayed.

The protocol field displays the radio communication that occurs between the launchpad and the flight computer. The times at which the messages were sent are indicated within the square brackets.

Moreover, the rocket orientation in the pitch and yaw axes is visualized by a 3D rendering of a rocket rotated by the corresponding amount. In addition, the TVC mount is shown below the rendering of the rocket to indicate the current angle of the TVC

Additionally, these orientation values are plotted in a line graph to show their progression over time. We created all these line plots in this application by using the real-time data plotter class by Sebastian Nilsson. For added functionality, we modified the class to enable automatic scaling of the vertical axis and to allow for the adjustment of the displayed sample size.

The launch application contains several of these line graphs: two to show the orientation of the rocket and TVC in the pitch and yaw axes, one to show the servo angles in the pitch and yaw axes, one for altitude, and one for acceleration in the Z axis.

Moreover, the altitude is represented by a yellow rendering of the rocket. This 3D rendering indicates the total orientation combining the pitch, yaw, and roll axes rotation.

After completing the flight sequence, the back button above the stop button reappears. If this button is pressed, one returns to the mode selection window. There, the close/save mode must be selected to store the flight file to the SD card of the transmitter PCB.

Reconstruct Mode

In reconstruction mode, a pop-up text box prompts the user to enter the text file containing the flight data to be analyzed.

At its core, this mode is the same as the launch mode. However, the protocol field is spared, and additional features for better analysis capabilities are added.

Instead of the start button, a play button is featured. When the user presses this button, it initiates a real-time simulation of the selected flight and countdown. The user can pause this simulation by pressing the stop button that appears after the play button is pressed. With the replay button left next to the play/stop button, the flight simulation can be restarted.

Using the sliders above the acceleration diagram (Figure 28), the user can adjust the flight playback speed within a range of 10% to 200% and select the number of samples displayed on the graphs.

The user can access the flight specifications by clicking the specs button above the acceleration graph. These include engine details (force and burn time), ignition delay time, and rocket mass.

Furthermore, it provides values such as maximum apogee, estimated time to reach this altitude, and approximate descent times, both with and without a parachute.

The user can switch between diagrams using the top-left button. For example, the user can switch the TVC orientation diagram to a PID diagram that allows a more detailed analysis of each PID component. Likewise, the user can change the acceleration diagram to a temperature diagram.

Video Overview of JM Eagle Control

Project by Johannes Moser

JM Eagle Control

Launch Mode

Reconstruct Mode

Video Overview of JM Eagle Control

Buffalo Pro & Max

Buffalo

JM Space