3._CRD Test_NN1 Method_NN1 and_CJC Sensor_NN1 Description_NN1 
The_AT0 Identification_NN1 and_CJC Isolation_NN1 of_PRF Robot_NP0 Workcell_NP0 Accuracy_NN1 Degradation_NN1 test_NN1 method_NN1 was_VBD developed_VVN in_PRP concert_NN1 with_PRP a_AT0 multirobot_AJ0 testbed_NN1 at_PRP NIST_NN1 ._SENT Figure_NN1 1_CRD presents_VVZ the_AT0 NIST_NN1 's_POS PHM_NN1 for_PRP Robot_NN1 Systems_NN2 testbed_NN1 with_PRP many_DT0 representative_AJ0 features_NN2 of_PRF a_AT0 manufacturing_NN1 robot_NN1 workcell_NN1 including_PRP robots_NN2 ,_PUN controllers_NN2 ,_PUN and_CJC end-of-arm_AJ0 tools_NN2 ._SENT The_AT0 testbed_NN1 features_VVZ two_CRD six_CRD degrees-of-freedom_NN1 (_PUL 6DOF_AJ0 )_PUR Universal_AJ0 Robots_NN2 ,_PUN each_DT0 with_PRP industrial_AJ0 controllers_NN2 ._SENT The_AT0 smaller_AJC robot_NN1 ,_PUN a_AT0 UR3_NN1 (_PUL shown_VVN on_PRP the_AT0 left_NN1 in_PRP Fig._NN1 1_CRD )_PUR ,_PUN is_VBZ configured_VVN to_TO0 perform_VVI path-planning_AJ0 operations_NN2 including_PRP drawing_VVG several_DT0 unique_AJ0 patterns_NN2 while_CJS the_AT0 larger_AJC robot_NN1 ,_PUN a_AT0 UR5_NN1 (_PUL shown_VVN on_PRP the_AT0 right_NN1 in_PRP Fig._NN1 1_CRD )_PUR ,_PUN is_VBZ configured_VVN to_TO0 perform_VVI a_AT0 material_NN1 handling_NN1 operation_NN1 ._SENT The_AT0 UR3_NN1 is_VBZ configured_VVN with_PRP a_AT0 pen_NN1 at_PRP its_DPS tool-center-position_NN1 using_VVG a_AT0 specially_AV0 designed_VVN mount_NN1 ._SENT The_AT0 UR5_NN1 is_VBZ configured_VVN with_PRP an_AT0 RG2_AJ0 gripper_NN1 that_DT0 is_VBZ controlled_VVN through_PRP the_AT0 UR5_NN1 's_POS controller_NN1 ._SENT Supervisory_AJ0 commands_NN2 are_VBB issued_VVN to_PRP both_DT0 the_AT0 UR3_NN1 and_CJC the_AT0 UR5_NN1 by_PRP a_AT0 single_AJ0 Beckhoff_NP0 PLC_NN1 ._SENT 
The_AT0 testbed_NN1 's_POS primary_AJ0 manufacturing-relevant_AJ0 use_NN1 case_NN1 is_VBZ for_PRP the_AT0 larger_AJC robot_NN1 to_TO0 physically_AV0 place_VVI test_NN1 parts_NN2 on_PRP fixtures_NN2 within_PRP the_AT0 reach_NN1 of_PRF the_AT0 path-planning_AJ0 robot_NN1 for_PRP this_DT0 smaller_AJC robot_NN1 to_TO0 draw_VVI on_PRP the_AT0 test_NN1 part_NN1 ._SENT This_DT0 drawing_NN1 activity_NN1 is_VBZ analogous_AJ0 to_PRP welding_NN1 ,_PUN adhesive_AJ0 application_NN1 ,_PUN and_CJC additive_AJ0 manufacturing_NN1 processes_NN2 performed_VVN by_PRP six-degree-of-freedom_AJ0 robot_NN1 systems_NN2 ._SENT Additional_AJ0 information_NN1 on_PRP the_AT0 testbed_NN1 and_CJC use_NN1 case_NN1 is_VBZ shown_VVN in_PRP Refs_NN2 ._SENT ._SENT 
The_AT0 Identification_NN1 and_CJC Isolation_NN1 of_PRF Robot_NP0 Workcell_NP0 Accuracy_NN1 Degradation_NN1 test_NN1 method_NN1 involves_VVZ testing_VVG the_AT0 positioning_NN1 repeatability_NN1 ,_PUN and_CJC therefore_AV0 the_AT0 health_NN1 ,_PUN of_PRF different_AJ0 components_NN2 along_PRP the_AT0 robot_NN1 workcell_NN1 's_POS kinematic_AJ0 chain_NN1 ._SENT The_AT0 test_NN1 method_NN1 uses_VVZ the_AT0 NIST-developed_AJ0 Position_NN1 Verification_NN1 Sensor_NN1 with_PRP Discrete_AJ0 Output_NN1 (_PUL PVS_NN2 )_PUR sensor_NN1 (_PUL depicted_VVN in_PRP Fig._NN1 2_CRD )_PUR to_TO0 measure_VVI the_AT0 positioning_NN1 of_PRF the_AT0 components_NN2 in_PRP question_NN1 ._SENT The_AT0 test_NN1 method_NN1 is_VBZ robot_NN1 agnostic_NN1 ;_PUN it_PNP can_VM0 be_VBI integrated_VVN and_CJC executed_VVN with_PRP any_DT0 6DOF_AJ0 robot_NN1 workcell_NN1 ._SENT When_CJS different_AJ0 measurement_NN1 points_NN2 along_PRP the_AT0 kinematic_AJ0 chain_NN1 are_VBB tested_VVN ,_PUN the_AT0 test_NN1 method_NN1 's_POS results_NN2 aim_VVB to_TO0 isolate_VVI any_DT0 source_NN1 (_PUL s_ZZ0 )_PUR of_PRF the_AT0 error_NN1 ,_PUN so_AV0 the_AT0 responsible_AJ0 component_NN1 can_VM0 be_VBI appropriately_AV0 addressed_VVN ._SENT Implementing_VVG the_AT0 test_NN1 method_NN1 first_ORD involves_VVZ affixing_VVG mechanical_AJ0 keys_NN2 at_PRP strategic_AJ0 locations_NN2 along_PRP the_AT0 workcell_NN1 's_POS kinematic_AJ0 chain_NN1 that_CJT can_VM0 present_VVI positional_AJ0 degradation_NN1 ._SENT The_AT0 PVS_NN2 is_VBZ physically_AV0 installed_VVN within_PRP the_AT0 workcell_NN1 's_POS work_NN1 volume_NN1 ._SENT The_AT0 keys_NN2 are_VBB commercial-off-the-shelf_AJ0 (_PUL COTS_NN2 )_PUR items_NN2 with_PRP precise_AJ0 geometries_NN2 ._SENT The_AT0 dimensions_NN2 of_PRF the_AT0 keys_NN2 are_VBB in_PRP English_AJ0 units_NN2 so_CJS the_AT0 sensor_NN1 's_POS clearance_NN1 dimension_NN1 is_VBZ manufactured_VVN in_PRP English_AJ0 units_NN2 ._SENT 
In_PRP the_AT0 case_NN1 of_PRF the_AT0 NIST_AJ0 testbed_NN1 ,_PUN keys_NN2 have_VHB been_VBN attached_VVN to_PRP multiple_AJ0 elements_NN2 including_PRP the_AT0 robot_NN1 's_POS tool_NN1 flange_NN1 ,_PUN physical_AJ0 mount_NN1 of_PRF the_AT0 gripper_NN1 jaws_NN2 ,_PUN and_CJC the_AT0 movable_AJ0 gripper_NN1 jaws_NN2 ,_PUN themselves_PNX (_PUL shown_VVN in_PRP Fig._NN1 3_CRD )_PUR ._SENT Once_CJS the_AT0 keys_NN2 are_VBB installed_VVN ,_PUN the_AT0 robot_NN1 ,_PUN along_AVP with_PRP the_AT0 other_AJ0 movable_AJ0 elements_NN2 in_PRP the_AT0 kinematic_AJ0 chain_NN1 (_PUL e.g._AV0 ,_PUN gripper_NN1 )_PUR ,_PUN is_VBZ systematically_AV0 programmed_VVN to_TO0 "_PUQ insert_VVI "_PUQ their_DPS keys_NN2 into_PRP the_AT0 PVS_NN2 ._SENT The_AT0 PVS_NN2 is_VBZ designed_VVN such_DT0 that_CJT the_AT0 key_NN1 can_VM0 be_VBI successfully_AV0 inserted_VVN within_PRP a_AT0 specific_AJ0 tolerance_NN1 as_CJS determined_VVN by_PRP the_AT0 dimensions_NN2 of_PRF the_AT0 key_NN1 and_CJC the_AT0 opening_NN1 of_PRF the_AT0 PVS_NN2 ._SENT If_CJS the_AT0 key_NN1 's_POS position_NN1 is_VBZ inaccurate_AJ0 beyond_PRP the_AT0 tolerance_NN1 of_PRF the_AT0 PVS_NN2 '_POS opening_NN1 ,_PUN then_AV0 the_AT0 test_NN1 of_PRF that_DT0 specific_AJ0 point_NN1 will_VM0 fail_VVI ._SENT Otherwise_AV0 ,_PUN if_CJS the_AT0 movement_NN1 of_PRF the_AT0 key_NN1 is_VBZ within_PRP the_AT0 tolerance_NN1 of_PRF the_AT0 PVS_NN2 '_POS opening_NN1 ,_PUN then_AV0 the_AT0 key_NN1 will_VM0 be_VBI successfully_AV0 inserted_VVN into_PRP the_AT0 PVS_NN2 and_CJC this_DT0 specific_AJ0 point_NN1 will_VM0 pass_VVI ._SENT The_AT0 element_NN1 to_PRP which_DTQ the_AT0 key_NN1 is_VBZ attached_VVN when_CJS a_AT0 failure_NN1 is_VBZ observed_VVN highlights_VVZ the_AT0 approximate_AJ0 location_NN1 of_PRF the_AT0 degradation_NN1 within_PRP the_AT0 kinematic_AJ0 chain_NN1 ._SENT More_DT0 details_NN2 are_VBB available_AJ0 in_PRP Refs_NN2 ._SENT ._SENT 
The_AT0 insertion_NN1 of_PRF the_AT0 key_NN1 into_PRP the_AT0 PVS_NN2 is_VBZ being_VBG verified_VVN to_TO0 determine_VVI what_DTQ uncertainty_NN1 ,_PUN if_CJS any_DT0 ,_PUN exists_VVZ regarding_PRP the_AT0 known_AJ0 tolerances_NN2 of_PRF the_AT0 fit_NN1 ._SENT For_PRP example_NN1 ,_PUN if_CJS the_AT0 clearance_NN1 between_PRP the_AT0 key_NN1 and_CJC the_AT0 PVS_NN2 is_VBZ designed_VVN to_PRP 25_CRD μm_NN2 ,_PUN then_AV0 the_AT0 ideal_AJ0 scenario_NN1 is_VBZ that_CJT the_AT0 key_NN1 has_VHZ a_AT0 range_NN1 of_PRF motion_NN1 of_PRF 25_CRD μm_NN2 regarding_PRP its_DPS insertion_NN1 into_PRP the_AT0 PVS_NN2 ._SENT Realistically_AV0 speaking_VVG ,_PUN uncertainties_NN2 exist_VVB including_PRP manufacturing_NN1 tolerances_NN2 of_PRF the_AT0 key_NN1 and_CJC the_AT0 PVS_NN2 ,_PUN the_AT0 setup_NN1 error_NN1 of_PRF the_AT0 key_NN1 with_PRP respect_NN1 to_PRP the_AT0 PVS_NN2 ,_PUN etc._AV0 
As_CJS noted_VVN earlier_AV0 ,_PUN the_AT0 PVS_NN2 provides_VVZ binary_AJ0 output_NN1 ,_PUN meaning_VVG that_CJT the_AT0 element_NN1 being_VBG tested_VVN either_AV0 passes_VVZ or_CJC fails_VVZ its_DPS specific_AJ0 positioning_NN1 test_NN1 ._SENT If_CJS all_DT0 elements_NN2 can_VM0 insert_VVI the_AT0 key_NN1 into_PRP the_AT0 PVS_NN2 ,_PUN then_AV0 the_AT0 workcell_NN1 is_VBZ considered_VVN healthy_AJ0 to_PRP the_AT0 designed_VVN tolerance_NN1 between_PRP the_AT0 key_NN1 and_CJC the_AT0 PVS_NN2 ._SENT If_CJS an_AT0 element_NN1 fails_VVZ ,_PUN then_AV0 that_CJT data_NN0 can_VM0 be_VBI used_VVN to_TO0 determine_VVI specifically_AV0 where_CJS within_PRP the_AT0 workcell_NN1 a_AT0 change_NN1 or_CJC degradation_NN1 has_VHZ occurred_VVN ._SENT By_PRP itself_PNX ,_PUN or_CJC coupled_VVN with_PRP other_AJ0 data_NN0 from_PRP the_AT0 workcell_NN1 's_POS operations_NN2 ,_PUN these_DT0 data_NN0 can_VM0 be_VBI used_VVN to_PRP then_AV0 efficiently_AV0 respond_VVI to_PRP that_DT0 change_NN1 ._SENT The_AT0 declaration_NN1 that_CJT the_AT0 workcell_NN1 is_VBZ healthy_AJ0 to_PRP the_AT0 designed_VVN tolerance_NN1 is_VBZ only_AV0 true_AJ0 if_CJS all_DT0 uncertainties_NN2 are_VBB known_VVN and_CJC quantified_VVN ._SENT If_CJS not_XX0 ,_PUN for_PRP example_NN1 ,_PUN a_AT0 kinematic_AJ0 chain_NN1 that_CJT successfully_AV0 passes_VVZ all_DT0 tests_NN2 with_PRP a_AT0 tolerance_NN1 of_PRF 25_CRD μm_NN2 may_VM0 only_AV0 be_VBI healthy_AJ0 to_PRP 50_CRD μm_NN2 or_CJC larger_AJC ._SENT Whatever_DTQ it_PNP may_VM0 be_VBI ,_PUN it_PNP is_VBZ critical_AJ0 for_PRP the_AT0 manufacturer_NN1 to_TO0 know_VVI exactly_AV0 what_DTQ they_PNP are_VBB testing_VVG ._SENT The_AT0 verification_NN1 testing_NN1 of_PRF the_AT0 PVS_NN2 is_VBZ a_AT0 core_NN1 step_NN1 in_PRP ultimately_AV0 determining_VVG the_AT0 uncertainty_NN1 of_PRF the_AT0 overall_AJ0 test_NN1 method_NN1 ._SENT 
4._CRD Experimental_AJ0 Design_NN1 
The_AT0 PVS_NN2 '_POS performance_NN1 needs_VVZ to_TO0 be_VBI verified_VVN to_TO0 understand_VVI its_DPS capability_NN1 and_CJC measurement_NN1 uncertainties_NN2 as_CJS it_PNP is_VBZ used_VVN within_PRP the_AT0 test_NN1 method_NN1 ._SENT The_AT0 PVS_NN2 is_VBZ actively_AV0 being_VBG tested_VVN to_TO0 gather_VVI this_DT0 information_NN1 ._SENT A_AT0 verification_NN1 test_NN1 process_NN1 has_VHZ been_VBN developed_VVN using_VVG an_AT0 automated_AJ0 ,_PUN linear_AJ0 ,_PUN three-axis_AJ0 stage_NN1 ._SENT The_AT0 test_NN1 stand_NN1 is_VBZ set_VVN up_AVP such_DT0 that_CJT a_AT0 standard_AJ0 key_NN1 is_VBZ mounted_VVN to_PRP the_AT0 three-axis_AJ0 stage_NN1 and_CJC a_AT0 PVS_NN2 is_VBZ mounted_VVN directly_AV0 below_AV0 (_PUL as_CJS shown_VVN in_PRP Fig._NN1 4_CRD )_PUR ._SENT The_AT0 stage_NN1 can_VM0 then_AV0 be_VBI commanded_VVN to_TO0 move_VVI and_CJC insert_VVI the_AT0 key_NN1 into_PRP the_AT0 PVS_NN2 at_PRP different_AJ0 locations_NN2 in_PRP an_AT0 attempt_NN1 to_TO0 achieve_VVI a_AT0 positive_AJ0 response_NN1 from_PRP the_AT0 PVS_NN2 (_PUL i.e._AV0 ,_PUN the_AT0 key_NN1 is_VBZ successfully_AV0 inserted_VVN into_PRP the_AT0 sensor_NN1 )_PUR ._SENT This_DT0 test_NN1 stand_NN1 simulates_VVZ robot_NN1 movement_NN1 with_PRP an_AT0 attempt_NN1 to_TO0 insert_VVI the_AT0 key_NN1 into_PRP the_AT0 PVS_NN2 and_CJC the_AT0 repeatability_NN1 uncertainties_NN2 that_CJT exist_VVB within_PRP them_PNP ._SENT 
This_DT0 test_NN1 process_NN1 was_VBD previously_AV0 performed_VVN manually_AV0 where_CJS there_EX0 was_VBD a_AT0 desire_NN1 to_TO0 automate_VVI the_AT0 process_NN1 because_CJS of_PRF the_AT0 manual_AJ0 process_NN1 being_VBG tedious_AJ0 ,_PUN cumbersome_AJ0 ,_PUN and_CJC susceptible_AJ0 to_PRP human_AJ0 error_NN1 ._SENT Stage_NN1 movement_NN1 had_VHD previously_AV0 been_VBN controlled_VVN using_VVG manual_AJ0 micrometers_NN2 ,_PUN for_PRP the_AT0 X-_NN1 and_CJC Y-axis_NN1 ,_PUN and_CJC a_AT0 lever_NN1 for_PRP the_AT0 Z-axis_NN1 (_PUL shown_VVN in_PRP Fig._NN1 5_CRD )_PUR ._SENT The_AT0 X_ZZ0 and_CJC Y_ZZ0 movements_NN2 test_NN1 different_AJ0 locations_NN2 or_CJC points_NN2 of_PRF the_AT0 sensor_NN1 while_CJS the_AT0 Z-axis_NN1 movement_NN1 is_VBZ used_VVN to_TO0 engage_VVI or_CJC disengage_VVI the_AT0 key_NN1 from_PRP the_AT0 PVS_NN2 ._SENT The_AT0 chosen_AJ0 devices_NN2 enabled_VVD the_AT0 user_NN1 to_TO0 move_VVI the_AT0 stage_NN1 in_PRP increments_NN2 of_PRF 1_CRD μm_NN2 at_PRP a_AT0 time_NN1 providing_VVG very_AV0 granular_AJ0 control_NN1 of_PRF the_AT0 stage_NN1 's_POS movements_NN2 ._SENT To_TO0 automate_VVI the_AT0 movement_NN1 of_PRF the_AT0 stage_NN1 ,_PUN the_AT0 micrometers_NN2 and_CJC lever_NN1 have_VHB been_VBN replaced_VVN with_PRP three_CRD motor_NN1 controllers_NN2 that_CJT are_VBB connected_VVN to_PRP three_CRD actuators_NN2 (_PUL shown_VVN in_PRP Fig._NN1 4_CRD )_PUR ._SENT This_DT0 new_AJ0 hardware_NN1 has_VHZ the_AT0 same_DT0 range_NN1 of_PRF motion_NN1 and_CJC resolution_NN1 as_PRP the_AT0 manually_AV0 driven_AJ0 stage_NN1 ._SENT 
A_AT0 matlab_AJ0 program_NN1 (_PUL running_VVG off_AVP a_AT0 laptop_NN1 personal_AJ0 computer_NN1 (_PUL PC_NP0 )_PUR that_DT0 is_VBZ connected_VVN via_PRP a_AT0 universal_AJ0 serial_AJ0 bus_NN1 (_PUL USB_NP0 )_PUR to_PRP the_AT0 motor_AJ0 controllers_NN2 of_PRF the_AT0 linear_AJ0 stage_NN1 )_PUR provides_VVZ a_AT0 test_NN1 grid_NN1 encompassing_VVG the_AT0 top_AJ0 hole_NN1 of_PRF the_AT0 PVS_NN2 ._SENT This_DT0 grid_NN1 consists_VVZ of_PRF points_NN2 to_TO0 be_VBI tested_VVN ,_PUN with_PRP the_AT0 size_NN1 and_CJC resolution_NN1 of_PRF the_AT0 grids_NN2 (_PUL i.e._AV0 ,_PUN the_AT0 number_NN1 of_PRF points_NN2 to_TO0 be_VBI tested_VVN and_CJC spacing_NN1 between_PRP points_NN2 )_PUR determined_VVN by_PRP user_NN1 input_NN1 ._SENT The_AT0 program_NN1 then_AV0 selects_VVZ the_AT0 order_NN1 for_PRP which_DTQ the_AT0 test_NN1 points_NN2 are_VBB evaluated_VVN by_PRP using_VVG one_CRD of_PRF three_CRD user-selected_AJ0 methods_NN2 (_PUL i.e._AV0 ,_PUN random_AJ0 pattern_NN1 ,_PUN vertical_AJ0 movement_NN1 testing_VVG each_DT0 Y-column_NN1 before_CJS moving_VVG onto_PRP the_AT0 next_ORD ,_PUN or_CJC horizontal_AJ0 movement_NN1 testing_VVG each_DT0 X-row_NN1 before_CJS moving_VVG onto_PRP the_AT0 next_ORD )_PUR and_CJC commands_VVZ the_AT0 stage_NN1 to_TO0 move_VVI the_AT0 key_NN1 to_PRP those_DT0 points_NN2 ._SENT At_PRP each_DT0 point_NN1 ,_PUN the_AT0 stage_NN1 will_VM0 attempt_VVI to_TO0 insert_VVI the_AT0 key_NN1 into_PRP the_AT0 PVS_NN2 ._SENT The_AT0 PVS_NN2 '_POS digital_AJ0 output_NN1 is_VBZ connected_VVN to_PRP an_AT0 oscilloscope_NN1 ,_PUN which_DTQ is_VBZ used_VVN to_TO0 determine_VVI the_AT0 success_NN1 of_PRF each_DT0 attempted_AJ0 insertion_NN1 ._SENT The_AT0 oscilloscope_NN1 measures_VVZ the_AT0 output_NN1 voltage_NN1 of_PRF the_AT0 sensor_NN1 at_PRP each_DT0 test_NN1 point_NN1 ,_PUN which_DTQ is_VBZ then_AV0 input_VVN into_PRP the_AT0 matlab_AJ0 program_NN1 ._SENT The_AT0 oscilloscope_NN1 is_VBZ connected_VVN to_PRP the_AT0 same_DT0 PC_NN1 laptop_NN1 via_PRP USB_NP0 connection_NN1 ._SENT Upon_PRP receiving_VVG the_AT0 signal_NN1 input_NN1 from_PRP the_AT0 oscilloscope_NN1 ,_PUN the_AT0 program_NN1 can_VM0 determine_VVI if_CJS the_AT0 insertion_NN1 was_VBD successful_AJ0 or_CJC not_XX0 based_VVN on_PRP the_AT0 captured_VVN voltage_NN1 value_NN1 (_PUL high_AJ0 voltage_NN1 indicates_VVZ success_NN1 )_PUR ._SENT Each_DT0 test_NN1 result_NN1 is_VBZ recorded_VVN within_PRP the_AT0 program_NN1 ._SENT Sample_NN1 output_NN1 from_PRP the_AT0 matlab_NN1 is_VBZ shown_VVN in_PRP Fig._NN1 6._CRD Movements_NN2 of_PRF the_AT0 stage_NN1 are_VBB programmed_VVN via_PRP matlab_NN1 in_PRP English_AJ0 Units_NN2 given_VVN the_AT0 English_AJ0 dimensions_NN2 of_PRF the_AT0 COTS_NN2 key_AJ0 ._SENT 
The_AT0 results_NN2 of_PRF the_AT0 insertion_NN1 at_PRP each_DT0 point_NN1 are_VBB stored_VVN ,_PUN formatted_VVN into_PRP grids_NN2 ,_PUN and_CJC exported_VVN into_PRP MS_NP0 Excel_VVB ®_NN0 ._SENT Each_DT0 point_NN1 in_PRP the_AT0 grid_NN1 contains_VVZ either_AV0 a_AT0 green_AJ0 "_PUQ 1_CRD "_PUQ (_PUL indicating_VVG a_AT0 successful_AJ0 test_NN1 point_NN1 )_PUR or_CJC a_AT0 red_AJ0 "_PUQ 0_CRD "_PUQ (_PUL indicated_VVN as_PRP a_AT0 failed_AJ0 test_NN1 point_NN1 )_PUR ._SENT These_DT0 grids_NN2 advance_VVB the_AT0 understanding_NN1 of_PRF how_AVQ the_AT0 sensor_NN1 performs_VVZ ._SENT Due_AJ0 to_PRP the_AT0 circular_AJ0 shape_NN1 of_PRF the_AT0 mating_AJ0 hole_NN1 on_PRP the_AT0 sensor_NN1 ,_PUN it_PNP is_VBZ expected_VVN that_CJT the_AT0 results_NN2 from_PRP each_DT0 test_NN1 will_VM0 be_VBI a_AT0 grid_NN1 with_PRP a_AT0 tight_AJ0 center_NN1 circle_NN1 of_PRF successful_AJ0 test_NN1 points_NN2 surrounded_VVN by_PRP unsuccessful_AJ0 test_NN1 points_NN2 ._SENT Figure_NN1 7_CRD present_AJ0 results_NN2 of_PRF random_AJ0 ,_PUN horizontal_AJ0 ,_PUN and_CJC vertical_AJ0 ordered_AJ0 tests_NN2 with_PRP a_AT0 12_CRD ×_PRP 12_CRD grid_NN1 (_PUL for_PRP 144_CRD total_AJ0 test_NN1 points_NN2 )_PUR and_CJC a_AT0 stated_AJ0 key_NN1 and_CJC sensor_NN1 clearance_NN1 of_PRF 25_CRD μm_NN2 ._SENT 
5._CRD Testing_NN1 and_CJC Results_NN2 
Preliminary_AJ0 sensor_NN1 testing_NN1 has_VHZ been_VBN performed_VVN using_VVG this_DT0 new_AJ0 automated_AJ0 test_NN1 method_NN1 ._SENT Testing_NN1 was_VBD performed_VVN on_PRP two_CRD unique_AJ0 PVS_NN2 's_VBZ that_CJT differed_VVD in_PRP the_AT0 material_NN1 of_PRF a_AT0 single_AJ0 internal_AJ0 component_NN1 ;_PUN one_CRD sensor_NN1 's_POS component_NN1 is_VBZ made_VVN from_PRP 3D-printed_AJ0 plastic_NN1 ,_PUN and_CJC the_AT0 other_AJ0 sensor_NN1 's_POS component_NN1 is_VBZ made_VVN from_PRP machined_AJ0 stainless_AJ0 steel_NN1 (_PUL SS_NP0 )_PUR ._SENT The_AT0 PVS_NN2 with_PRP the_AT0 SS_NP0 component_NN1 was_VBD found_VVN to_TO0 be_VBI of_PRF much_DT0 higher_AJC precision_NN1 than_CJS the_AT0 PVS_NN2 with_PRP the_AT0 3D-printed_AJ0 plastic_NN1 component_NN1 ._SENT 
Testing_NN1 of_PRF the_AT0 measurement_NN1 test_NN1 stand_NN1 ,_PUN along_AVP with_PRP capturing_VVG preliminary_AJ0 verification_NN1 results_NN2 of_PRF the_AT0 PVS_NN2 ,_PUN began_VVD by_PRP conducting_VVG 55_CRD total_AJ0 tests_NN2 on_PRP a_AT0 single_AJ0 PVS_NN2 ._SENT These_DT0 tests_NN2 consisted_VVD of_PRF grid_NN1 size_NN1 XX_NP0 and_CJC resolution_NN1 YY_NP0 ,_PUN where_AVQ XX_NP0 and_CJC YY_NP0 are_VBB test-specified_AJ0 variables_NN2 for_PRP grid_NN1 size_NN1 and_CJC resolution_NN1 ,_PUN respectively_AV0 ._SENT The_AT0 order_NN1 that_CJT the_AT0 individual_AJ0 observations_NN2 were_VBD collected_VVN varied_AJ0 across_PRP the_AT0 55_CRD tests_NN2 such_DT0 that_DT0 19_CRD tests_NN2 were_VBD collected_VVN in_PRP random_AJ0 order_NN1 ,_PUN 18_CRD tests_NN2 in_PRP vertical_AJ0 order_NN1 ,_PUN and_CJC 18_CRD tests_NN2 in_PRP horizontal_AJ0 order_NN1 ._SENT Ideally_AV0 ,_PUN it_PNP is_VBZ expected_VVN that_CJT the_AT0 successful_AJ0 sensor_NN1 results_NN2 would_VM0 create_VVI a_AT0 precise_AJ0 circular_AJ0 pattern_NN1 ,_PUN within_PRP the_AT0 resolution_NN1 of_PRF the_AT0 test_NN1 grid_NN1 ,_PUN with_PRP a_AT0 diameter_NN1 equal_AJ0 to_PRP the_AT0 diameter_NN1 of_PRF the_AT0 key_NN1 ._SENT All_DT0 other_AJ0 areas_NN2 of_PRF the_AT0 test_NN1 grid_NN1 should_VM0 result_VVI in_PRP unsuccessful_AJ0 sensor_NN1 results_NN2 ._SENT The_AT0 results_NN2 of_PRF the_AT0 testing_NN1 done_VDN with_PRP this_DT0 PVS_NN2 deviated_VVN from_PRP the_AT0 expected_AJ0 results_NN2 ._SENT The_AT0 circle_NN1 of_PRF successful_AJ0 test_NN1 observations_NN2 encompassed_VVD most_DT0 of_PRF the_AT0 grid_NN1 as_CJS opposed_VVN to_PRP the_AT0 tight_AJ0 ,_PUN expected_AJ0 center_NN1 region_NN1 ._SENT This_DT0 led_VVD to_PRP the_AT0 dissection_NN1 of_PRF the_AT0 first_ORD PVS_NN2 revealing_VVG the_AT0 internal_AJ0 3D-printed_AJ0 component_NN1 ._SENT Given_VVN that_CJT the_AT0 parts_NN2 from_PRP this_DT0 material_NN1 type_NN1 are_VBB less_AV0 precise_AJ0 than_CJS the_AT0 parts_NN2 machined_VVN in_PRP SS_NP0 ,_PUN the_AT0 SS_NP0 PVS_NN2 was_VBD then_AV0 integrated_VVN into_PRP the_AT0 measurement_NN1 test_NN1 stand_NN1 ._SENT Fifteen_CRD total_AJ0 tests_NN2 were_VBD run_VVN with_PRP the_AT0 SS_NP0 PVS_NN2 :_PUN five_CRD random_AJ0 order_NN1 ,_PUN six_CRD vertical_AJ0 order_NN1 ,_PUN and_CJC four_CRD horizontal_AJ0 order_NN1 ;_PUN each_DT0 with_PRP grid_NN1 size_NN1 XX_CRD =_NP0 12_CRD and_CJC resolution_NN1 YY_NP0 =_NP0 20.8_CRD μm_NN1 ._SENT The_AT0 grids_NN2 created_VVD using_VVG this_DT0 sensor_NN1 were_VBD more_AV0 closely_AV0 aligned_VVN with_PRP what_DTQ was_VBD originally_AV0 anticipated_VVN ;_PUN the_AT0 grid_NN1 was_VBD comprised_VVN of_PRF unsuccessful_AJ0 insertion_NN1 tests_NN2 ,_PUN while_CJS the_AT0 center_NN1 of_PRF the_AT0 grid_NN1 was_VBD comprised_VVN of_PRF a_AT0 tight_AJ0 ,_PUN circular_AJ0 shape_NN1 of_PRF successful_AJ0 tests_NN2 ._SENT In_PRP total_NN1 ,_PUN 71_CRD tests_NN2 have_VHB been_VBN completed_VVN as_CJS of_PRF the_AT0 preliminary_AJ0 development_NN1 of_PRF this_DT0 publication_NN1 ;_PUN 25_CRD random_AJ0 order_NN1 ,_PUN 24_CRD vertical_AJ0 order_NN1 ,_PUN and_CJC 22_CRD horizontal_AJ0 order_NN1 ._SENT These_DT0 tests_NN2 ranged_VVD in_PRP size_NN1 from_PRP 12_CRD observations_NN2 (_PUL a_AT0 very_AV0 preliminary_AJ0 3_CRD ×_PRP 4_CRD grid_NN1 to_TO0 confirm_VVI the_AT0 matlab_AJ0 code_NN1 )_PUR to_PRP 2500_CRD observations_NN2 ._SENT Test_NN1 times_NN2 ranged_VVN in_PRP duration_NN1 from_PRP about_AV0 five_CRD minutes_NN2 to_PRP about_AV0 13_CRD h_ZZ0 ._SENT 
Some_DT0 tests_NN2 had_VHD unexpected_AJ0 anomalies_NN2 ;_PUN there_EX0 were_VBD unsuccessful_AJ0 insertions_NN2 in_PRP the_AT0 middle_NN1 of_PRF the_AT0 grid_NN1 where_AVQ successful_AJ0 insertions_NN2 were_VBD expected_VVN or_CJC successful_AJ0 insertions_NN2 on_PRP the_AT0 outside_NN1 of_PRF the_AT0 grid_NN1 where_AVQ failed_AJ0 insertions_NN2 were_VBD expected_VVN ._SENT This_DT0 was_VBD a_AT0 very_AV0 common_AJ0 problem_NN1 that_CJT was_VBD faced_VVN throughout_PRP the_AT0 entire_AJ0 testing_NN1 process_NN1 ._SENT Figure_NN1 7_CRD presents_VVZ three_CRD ,_PUN 12_CRD ×_PRP 12_CRD grid_NN1 test_NN1 results_NN2 from_PRP random_AJ0 ,_PUN horizontal_AJ0 ,_PUN and_CJC vertical_AJ0 tests_NN2 using_VVG the_AT0 SS_NP0 PVS_NN2 that_CJT had_VHD a_AT0 designed_VVN key_NN1 /_PUN sensor_NN1 tolerance_NN1 of_PRF 25_CRD μm_NN2 ._SENT This_DT0 means_VVZ that_CJT the_AT0 PVS_NN2 opening_NN1 is_VBZ nominally_AV0 25_CRD μm_NN2 larger_AJC than_CJS the_AT0 diameter_NN1 of_PRF the_AT0 key_NN1 ._SENT For_PRP the_AT0 specific_AJ0 tests_NN2 that_CJT have_VHB been_VBN run_VVN and_CJC are_VBB discussed_VVN below_AV0 ,_PUN the_AT0 PVS_NN2 circular_AJ0 opening_NN1 has_VHZ a_AT0 machined_AJ0 tolerance_NN1 of_PRF 6.375_CRD mm_NN0 –_PUN 0.0_CRD to_PRP +12_CRD μm_NN2 while_CJS the_AT0 tolerance_NN1 of_PRF the_AT0 cylinder_NN1 key_NN1 is_VBZ 6.350_CRD mm_NN0 –_PUN 0_CRD to_PRP +5_CRD μm_NN2 ._SENT 
