Advance Modeling of a Skid-Steering Mobile Robot for Remote ...

1.2 The sensors 91.2 The sensorsFor this project, we employed three SCA620-CF8H1A 1-AXIS ANALOG ACCELEROMETERS[13]. The main characteristics are: power supply V dd = +5 V, voltage output V out ∈ [−0.3, V dd +0.3] V, acceleration range a ∈ [−1.7g, 1.7g], sensitivity error e a = [−3, +3]% and low-passbandwidth, in laboratory conditions, at 80 Hz [13].In order to characterize the robot vibrations as well as identify some dynamic parameters,each accelerometer was welded to one face of a small cube of wood, so that the accelerometer’sacceleration coincides with the cube’s acceleration. They were also fixed in such away that their axes intersect in one point, the origin of the cube frame, and their positivedirections satisfy the right-hand rule (Figure 1.2).The data are acquired from the accelerometers as Voltage signals by using the NI-DAQmxdevice, as data acquisition device (DAQ), and LabVIEW software, both produced by NationalInstruments Co.Figure 1.2: Picture of the wood-cube with the three 1-axis analog accelerometers and their axes.Also, the eXpert 2653 ADMET universal testing machine [14] in the mechanics laboratoryat Roger Williams University was utilized to perform tests for the identification ofthe tire reaction forces. The testing machine is capable of performing compression, tension,and flexure tests, thanks to its axial alignment, stiffness and cross-head guidance. The mainsystem specifications are: load capacity 50 kN, speed range [0.0025, 508] mmminand position