Traces Menu / Plotting

Showing the Plot

Click on the Display button to show a plot of the data that was collected from the test that was just run. Previously saved data can also be collected and graphed.

The default view is shown above. The red line is the closed loop response. The blue line is the open loop response (simulated from the closed loop response). The top half of the window is the Amplitude Response and the bottom half is the Phase Response.

Traces

Under Traces on the Bode Plot window menu, six traces can be selected. Each trace represents a different colored line displayed on the graph. This allows you to choose which traces you wish to display in the graph.

Simply click on a trace to either have the data graphed or not. The traces that are graphed are denoted by a check mark (The data collected from a sine sweep test is Closed Loop -> Measured).

The following traces are available:

Open Loop -> Measured - (G) This is the simulated open loop response calcluated from the closed loop data collected.

Open Loop -> Simulated - (G) This is the simulated open loop response above with a simulated fitler simulated in addition.

Closed Loop -> Measured - (G / (1 + G)) This is the data collected directly by the sine sweep test.

Closed Loop -> Simulated - (G / (1 + G)) This is the data collected with the filter on the axis being tested applied via simulation.

Filter -> Simulated - This is a simulation of the filter on the controller.

Filter -> Measured - This is a simulation of the filter that was on the controller at the time the Bode data was taken.

Sensitivity -> Simulated - (1 / (1 + G)) This is the Sensitivity of the closed loop response using the simulated filter.

Sensitivity -> Measured - (1 / (1 + G)) This is the Sensitivity of the closed loop response using the filter that was on the controller at the time the Bode data was taken.

Any combination of the above traces can be shown at the same time. Shown below is a plot of the open loop response, filter, and filtered open loop response of a particular system.

For more information on how the filters are simulated, see the Filter Simulation section.

All - You can quickly turn groups of traces on and off using the All menu item. The menu items in the All section do not get checks next to them. The associated items that they operate get checks turned on or off.

All -> Measured -> On Turns on all the measured traces mentioned above

All -> Measured -> Off Turns off all the measured traces mentioned above

All -> Simulated -> On Turns on all the simulated traces mentioned above

All -> Simulated -> Off Turns off all the simulated mentioned above

All -> On Turns on all the traces mentioned above

All -> Off Turns off all the traces mentioned above

Stability

There are two types of stability measurement available. You can use these measures to get a quantitative measure of how stable the system is.

Traces -> Stability -> Stability Displays the Stability plot as show on the stability page

Traces -> Stability -> Gain / Phase Margin Displays the Gain and Phase Margin plot as show on the stability page

Traces -> Stability -> None Turns off all stability measures

Smoothing Data

You can smooth out noisy data with the Smooth Data menu item. The data smoothing is not saved to the file, so you don't have to worry about corrupting your data.

To smooth the data, click Traces -> Smooth Data. You will get a pop up window to select the amount of smoothing you want to perform.

You can choose the amount of smoothing you would like to perform by adjusting the slider or typing in a value into the edit box. The smoothing is performed by averaging all data points within x percent of the data point in question, where x is the smoothing value you choose in the smoothing pop up window.

An example of before and after smoothing:

Before

After: The same data after 3 percent smoothing.

Trace Legend

Because several traces can be show at the same time, the Bode Tool uses a rigid set of colors to indicate which trace is which. A legend is displayed bBy clicking Traces -> Legend.

A small window will pop up that shows which color trace is which. The line width is exagerated in the legend so the colors are easier to see. The window can be repositioned to a convenient location for reference when looking at the plots in the view window.

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