Project Achievements - Phase 1
The main findings from the field trials in a real cargo hold on-board a bulk carrier were that the position of the probe head was not actuated with enough degrees of freedom in order to reach all the points of interest on the stiffener structures.
The next phase of design therefore focused on improving the agility of the probe holder and to improve the thickness reading capability.
Besides a few other improvements, an interesting modification, which was explored by the next design update, was the position of the LIDAR sensor. It was to be transferred to the moving actuator.
Project Achievements - Phase 2
An important and difficult maneuver when using the BIKE platform is the transition from one plane to another by means of crossing through a concave corner or by crossing over an edge (convex corner).
Figure 8: BIKE crossing over a convex corner (edge)
Figure 9: BIKE crossing over a concave corner
This maneuver relies on precise alignment of the BIKE robot with the edge. Furthermore, during the crossing, the operator needs to interpret the visual feedback correctly and manually adjust the robot controls for successful completion of the task.
For execution of the corner-crossing maneuver itself, the BIKE controller needs to switch from front-wheel to rear-wheel control, depending on the position of the robot in the corner and the direction of the maneuver. So far, this switch of wheel control schemes was either not performed at all (resulting in wheel slippage), or the operator needed to judge when to switch based on the visual feedback.
With the current implementation of the local controller, also an improved corner crossing controller was implemented, taking advantage of the IMU and Odometry based robot pose estimator used for path following and map building. Using only gyro-data from the IMU and wheel rotations, this pose estimator generates very accurate (local) robot pose updates. For the corner crossing, mainly the gyro-data is used to determine in what state of the transition from one plate to the next the robot currently is.