This menu is used to generate stick inputs that are introduced to the system. This is a way to check how the system behaves when a stick commands enters in the autopilot. For each channel, the user can set a continuos movement formed for example by a sine wave or a group of steps. There are a set of parameters to be modified for each one of the signals.
Test Stick Configuration
Configured parameters can be shown on the checklist in order to test the system prior to change flight phase. To activate the automatic movement, use the activation button on the virtual stick configured on the workspace.
Configure stick parameters for manual and assisted manual system control.
The movement that the pilot makes on the stick produces variations on a vector called R. The values reached by the components of R are limited between 0 and 1. These stick movements need to be processed to produce the input signals that will go into the navigation system (in the case of arcade), or directly into the servos (purely manual). The process begins by “mapping” each one of the sticks inputs to a vector called Y which has the size of the number of servos and relates the sticks with each one of them. For example, let’s consider a quadrocopter. In this case, if the pilot wants to apply more thrust, he moves one stick up so one value of R will become different from zero. In reality, this movement should produce an increase in the rotation speed of the four engines, so here the mapping will be that an increase in one component of R (throttle stick) has to produce an increase in the rotation of four engines, i.e one component of R affects four components of Y. Doing that with the rest of stick positions (pitch, yaw, roll) will generate a matrix, YR, which will transform the stick position into a servo movement.
The process will end here if the manual mode is used, but if the arcade mode is used, the objective is to obtain control input for the controller so the Y vector has to be further processed. The components of Y are transformed to “real” servo movement through the curve of each actuator (the one that appears in section 220.127.116.11). Then, the US matrix will transform the servo movement (S) into control inputs for the system (U).
To obtain the values of the YR matrix, the resultant matrix obtained after multiplying YR and US should be the identity matrix, so when SU is calculated, the matrix YR can be deduced.
These values of YR indicate the slope for the transformation between values of R and Y (its relation), so an offset has to be indicated to obtain the final expression. The equation that transforms raw stick inputs (R) to Y is: Y=YR*R+Y0.
- YR= Raw Channels to servo transformation matrix.
- R= Inputs from Stick.
- Y0=Offset after applying transformation to servos.
The offset is calculated by setting R and Y with the same values and solving the previous equation. For example, considering the neutral position of the sticks (0.5), if all the components of R and Y are set to this value, the solution for the offset vector will be: Y0=Yn-YR*Rn. The resultant would be the one to introduce in the blue box of the previous figure.
The option “Mask Servos” is used to select which servos will “listen” the commands sent by the stick. If the servo is selected (green box), it means that servo will be moved if a stick channel is configure to do so. On the other side, if a servo is not selected (gray box), it will ignore the commands sent from the stick.
It is possible to set multiple joystick inputs with the respective priority, from top to bottom.
UAV, MCU & Port refers to the Veronte unit where the servo is connected, time is the time without reception to change to the following input. Enable permits the reception of data from that stick and overwrite permits to have multiple inputs for different channels.
Configure virtual sticks on the system, select an input variable containing the stick data and select the Veronte unit destination to control.
Virtual Stick Configuration
The arcade trim is used to set as the zero the current stick position. In the process detailed above to obtain U from the stick input R, the final value is not the one that enters in the navigation algorithm, but the difference between the input U and another vector Uo, this one is the arcade trim. So when the sticks are trimmed at a certain position, the movement from that point will be the value of R that after the transformation will generate the U.
The values of the trim vector Uo can be written manually in the corresponding field or an automation can be created to do that automatically (recommended).
Arcade Trim Configuration Menu
In order to perform the Arcade Trim, once the automation is configured as described in the Automation section, it is sufficient to move the stick main levers to center and click on the Trim Arcade button. Then wait for 2-3 seconds and return the levers to default positions.