Route parameters and path finding
Third step is to review and set missing parameters of the route. In order to ensure a safe execution of the mission, it is crucial to understand and review all parameters before route is confirmed.
Take-off point altitude above ground m is drone real altitude relative to the ground. If drone is placed on an object above the ground level or in the pit below the ground level not represented in elevation data. Take-off point altitude is vital parameter for route calculation. It must be used when a vehicle takes off from a surface that is higher or lower than the ground (for example, a podium or a building roof). Another case when "Takeoff altitude" must be used is when the elevation data is incorrect. For example, if inspecting the career (or mound) that doesn't exist in the elevation model. If the career (or mound) doesn't exist in the elevation data, the below message will appear:
This message only appears when the drone is in RTK_FIX mode.
Note: it is highly recommended to always check altitude values. Altitude drift problems cannot be solved by software only and require operator attention. Always check, after power cycling a vehicle or mission upload, whether the altitude is reported correctly. UgCS tries to detect such conditions and issues a warning “It looks as if you have to power on/off your drone in order to reset barometer...” if RAW altitude reported by the vehicle is very different from 0 at the time of mission upload.
Home location - is a point where the vehicle should return in the case of a failsafe condition. Triggered automatically or by the operator giving the command to return home. Failsafe execution conditions usually include emergencies such as loss of RC or low battery charge level.
Option “Do not modify” defines that autopilot actions for this settings remain default and not modified. Option is located in the drop-down list for each Failsafe action.
The home position is usually the point of initialization.
To view additional data about the home location, move the mouse cursor on it. The available information consists of corresponding vehicle, current distance to the vehicle, coordinates and altitude of the home location and ground elevation at that point.
For ease of use, it is possible to view home location of the vehicle by clicking on “Focus on home location” command in the corresponding vehicle context.
Note: Every autopilot and thus vehicle might handle Home Location functionality differently. For safe use, please read the corresponding section in the vehicles VSM User guide.
Maximum altitude is the altitude used by the vehicle to return to the home position in emergency cases or when the operator recalls it during the mission. This altitude is default when setting new waypoint by double-clicking on the map.
Emergency return altitude is the altitude used by the vehicle to return to the home position in emergency cases or when the operator recalls it during the mission. This altitude is default when setting new waypoint by double-clicking on the map.
Altitude origin specifies whether altitudes are calculated from the mean sea level or from the level of terrain. Usually it is more convenient to specify altitudes relative to the ground level. Please note that once the choice is made, all the altitudes specified in the created route are interpreted in the chosen type. There is the option to change the altitude origin afterwards via the route options window.
Trajectory type is the parameter for defining the pattern of the route between two waypoints. Choosing the Straight option results in a direct line segment between the points whilst the Safe option generally produces two segments, one vertical and one horizontal, as schematically shown below.
The behavior of vehicles in different types of trajectories, and applicability of failsafe conditions, depend on the autopilot’s capabilities. For more information, check the manual and specifications of the device.
Action on GPS loss, action on RC loss, action on battery discharge and datalink loss are the pre-defined emergency actions. In all cases the option to wait or to land the vehicle can be chosen. Options to return to home position and to continue flight along the route are also available, provided GPS is operational.
Usually it is only required to specify the home position and safe altitude; other parameters have reasonable default values based on known vehicle properties. Still, it should be ensured that defaults are correct. The software will perform checks and will cancel route creation if incorrectly defined or conflicting values of parameters are present. Notifications about errors in values will display at the bottom of the window, and the particular parameter is highlighted.
After the route is formed with all segments in place and their parameters are double-checked, the mission is ready for processing.
The calculation process is executes automatically. The mission saves automatically when the route calculates. Calculation might take some time.
During the calculation process, the route is checked for feasibility according to predefined rules. First, it checks whether figures and parameters are specified correctly. All polygons must be connected and all parameters must be correctly specified before proceeding. Correct parameters must also be specified for actions attached to the route segments.
Calculated route build around NFZ and (refer par. “No Fly Zones”) and buildings.
To ease error correction for a route, a message will displayed pointing to incorrect values before route calculation proceeds. The first route segment with an invalid parameter is automatically selected. After the problem is fixed, UgCS automatically start route re-calculation. If there are no more errors, the calculation process will be launched.
The route card displays the status of the calculation (in the upper right corner).
• green check mark - the route is calculated, no errors are detected;
• yellow circle with a rotating - there is a route calculation;
• red triangle with an exclamation point - in the itinerary there is an error, change the parameters of points in the route.
To access log file saved on disk, see Troubleshooting section for default log paths.