Fig. 5: Closed-loop control with fluidic sensing.
a Superimposed pictures taken at the start and end of the size sorting experiment. The input order of the cylindrical objects was randomly selected. b gripper actuation pressure and coordinates of the Tool Center Point (TCP) over time during the sorting. The manipulations during each actuation cycle are explained in the corresponding schematics. The red band in the plot represents the pressure feedback measurement, and the yellow band represents the object movement. The four pressure feedback measurements (average ± standard deviation) are 34.80 ± 0.07 kPa, 35.36 ± 0.07 kPa, 35.05 ± 0.08 kPa, 34.13 ± 0.07 kPa, respectively. c Snapshots of the tomato picking experiment representing the measurement of pressure reference Pref and picking of the three tomatoes, respectively. d Gripper actuation pressure and TCP coordinates over time during the tomato picking. The red band represents the measurement of equilibrium pressure Peq, and the yellow band represents the tomato placement on the table. A pressure difference ΔP = Peq − Pref larger than 0.2 kPa is considered as a successful picking event.
