Invalid workspace variable specified as workspace input in 'RangeEsti​mation_Sim​ulink/From Workspace'. Time values must be non-decreasing.

I was using Kalman Filter Block from Control Toolbox. It asks for Input(U) and Measurement(Y) which I gave correctly. But I also need to add a time column with it ?

Answer 1

[Ayush Aniket]

Hi Sahil,

As per my understanding, the error message you have encountered, "Invalid workspace variable specified as workspace input in 'RangeEstimation_Simulink/From Workspace'. Time values must be non-decreasing," indicates a problem with the time values provided as workspace input in the 'From Workspace' block in Simulink.

The 'From Workspace' block in Simulink necessitates the data to be in a specific format, such as timeseries. Moreover, the time values in the input data should be of double data type and should increase monotonically, as these are referenced during the simulation time. For more information about the data types supported by this block, please refer to the following documentation link:

https://www.mathworks.com/help/simulink/slref/fromworkspace.html#bs_pusu

Assuming that you are using the 'From Workspace' block to provide the input variables Input(U) and Measurement(Y) for the Kalman Filter, these inputs must be paired and formatted into a time series format to be used as input with this specific block. Please refer to the example that utilizes both the 'From Workspace' and 'Kalman Filter' blocks, explaining the required format for the input data:

https://www.mathworks.com/help/control/ug/state-estimation-using-time-varying-kalman-filter.html

Hope it helps.