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manufacturing After the parts for the gripper and HIC subsystem and the robotic arm and RID subsystem, the separate subsystems were integrated into a complete and functional haptic manipulator complete with user interface. It was then determined that many experiments had to be done done to determine how well the system worked. These experiments were split into two separate categories, based on the subsystems that they involved. The gripper and HIC were tested separate from the arm controller and RID. Most of the parameters that were tested characterize the dynamic performance of the entire system. From analyzing the performance of each subsystem, the dynamic response of the functional haptic manipulator was determined. The dynamic performance of the system was the most important thing to test because the success of the system depended on how well the robotic arm responded to an input and how well the HIC conveyed forces to the operator of the robot. The tests done on the gripper and HIC are as follows: gripper and HIC pallet size, gripper and HIC mass, delay time, rise time, and percent overshoot. The gripper was measured to have a pallet size of 3.93 in2 with an uncertainty of plus or minus 0.53 in2. The HIC was measured to have a pallet size of 3.87 in2 with an uncertainty of 0.49 in2. The weight of the gripper was 1.188 kg with an uncertainty of 0.002 kg. The weight of the HIC was found to be 1.201 kg with an uncertainty of 0.002 kg. The uncertainty in measuring the pallet area was not determined because the accuracy of the measurement was not critical. The uncertainty in measuring the mass of the gripper and HIC was do to the instrument uncertainty inherent in the electronic scale. The delay time, rise time, and percent overshoot of the gripper and HIC were all determined by plotting 20 plots of the response of the system. A representative graph can be found in figure 1 below. 2.5 2.25 2 1.75 1.5 Force (N) 1.25 1 0.75 0.5 0.25 0 0 2 4 6 Tim e (sec) 8 10 12 Gripper HIC Figure 1 The delay time of the system was found to be 120 ms with an uncertainty of 6ms. The 10 to 90% rise time of the system was found to be 800 ms with an uncertainty of 35 ms. It was also determined that there was no overshoot, but that there was a steady state offset of 0.01 N with an uncertainty of 0.0005 N. The uncertainties were determined by adding an uncertainty of 0.5% FSO do to the Labview reading to the uncertainty inherent in reading the graph. It was assumed that the uncertainty do to reading the graph was 5%. These parameters indicate that the gripper and HIC subsystem accurately and quickly conveyed the force felt by the gripper to the operator of the system. The system meets the goals set by the team in the beginning of the year. The capability of the gripper and HIC system was greatly affected by the behavior of the force sensing resistors. Therefore, there were also several parameters of the sensors that were tested. The first parameter tested was repeatability. Assuming that the object comes in contact with the sensor in the same place in all trials, the repeatability of the sensors was found to be 100%. A mass was placed on a sensor 20 times, and it produced the same voltage output every time. The second parameter that was tested was the maximum and minimum force that the sensor was capable of sensing. The maximum force that was sensed was 13.33 N. The minimum that force the FSR could sense was 0.735 N. The last parameter that we test was the accuracy of the FSR. It was determined that the accuracy of the sensor was 0.36 N. This means that the actual force could be 0.36 N greater than or less than the sensed force. After determining that the gripper and HIC system worked well, the performance of the arm and RID were tested. The tests done on the robotic arm and RID are as follows: range of motion of the robotic arm, position repeatability of the system, and the delay time, rise time, and percent overshoot of the robotic arm and RID system were also measured. The rotational movement of the robotic arm was given in the IBM manual as 270 degrees. This was validated by physically moving the arm from one extreme to the other. The potentiometers used as sensors could be rotated by 360 degrees, so they did not affect the range of motion of the arm. The position repeatability was measured by taking data using Labview. The response of the arm to the same input was measured 20 times. From this test, it was determined that the greatest deviation from the desired position of 115.32 degrees was 1.5 degrees and 50% of the time, the resulting position of the arm was the desired position. The delay time, rise time, and percent overshoot of the robotic arm and RID were all determined by plotting 20 plots of the response of the system. A representative graph can be found in figure 2 below. -100 0 -115 -130 Angular Position (deg) -145 -160 -175 -190 -205 -220 -235 -250 RID Robotic Arm 1 2 3 4 Tim e (s) 5 6 7 8 9 10 11 Figure 2 From the graph, it was determined that the delay time of the system was 120 ms with an uncertainty of 6 ms. The 10 to 90% rise time of the system was determined to be 2.5 seconds with an uncertainty of 0.125 seconds. The graph shows that the response of the robotic arm displayed no overshoot, however it did display a steady state offset of 2 degrees with an uncertainty of 0.1 degrees. These parameters obtained from the graph, and the graph itself, indicate that the robotic arm is over-damped and that it never reaches the exact desired position, but the offset is very small. The uncertainty of the values obtained from the graph can be contributed to the uncertainty of 0.5% in the reading taken by Labview and also the uncertainty in reading the graph. The uncertainty in reading the graph was assumed to be 5%, and this value was the biggest contributor to the total uncertainty value obtained. The uncertainty do to the variance in values from test to test were negligible. The overall results of the experiments done to the robotic arm and RID show that the system is adequate and fulfills the initial goals of the project. The experiments done on the different subsystems measured some of the physical properties of each subsystem and also characterized the dynamic response of the system. The physical properties of the subsystem match well to the initial estimates first made during the design process. The dynamic behavior of the system as a whole also correlates well with the initial design estimates, but more importantly the plot in figure?? Shows that the gripper and HIC convey the force to the user, and the plot in figure?? Shows that the robotic arm reaches the desired position indicated by the RID. Therefore, these graphs illustrate that the entire robot and its user input devices are functional.

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