Verification of a Dynamic Grinding Model

1988 ◽  
Vol 110 (4) ◽  
pp. 403-409 ◽  
Author(s):  
T. R. Kurfess ◽  
D. E. Whitney ◽  
M. L. Brown
Keyword(s):  
Dynamic Model ◽  
Force Feedback ◽  
Intelligent System ◽  
Industrial Robot ◽  
Final Height ◽  
Feedback System ◽  
Weld Bead ◽  
Simulation Based ◽  
Measured Profile ◽  
Process Behavior

Many applications of industrial robot automation can be made possible or improved with the introduction of a force feedback system. The task of weld bead removal is being studied in an effort to develop a real time force controlled intelligent system. The process of weld bead grinding must be analyzed and modelled to develop a weld bead removal system. Previous research has developed and verified static models of grinding. This paper describes a dynamic model developed from the grinding characteristics demonstrated previously. An experimental grinding system was built and the measured process behavior was compared with a grinding simulation based on the dynamic model. The profile of the specimen was measured prior to and subsequent to grinding. The initial profile was used as an input to the simulation, and the output from the simulation was compared with the final measured profile. A variety of conditions was tested. For typical mean cut depths of 0.10 mm the simulator predicted the final height of the grinding specimen within a standard deviation of 0.02 mm. The dynamic model was verified within 10 percent of the actual results.

An Extended Kalman Filter for Collision Detection During Manipulator Contact Tasks

2014 ◽  
Author(s):  
Andy Zelenak ◽  
Mitch Pryor ◽  
Kyle Schroeder
Keyword(s):  
Kalman Filter ◽  
Dynamic Model ◽  
Extended Kalman Filter ◽  
Collision Detection ◽  
Force Feedback ◽  
Industrial Robot ◽  
Detection Algorithm ◽  
Industrial Robots ◽  
Joint Torque ◽  
Contact Tasks

The development of control strategies that allow stiff industrial robots to operate safely in unstructured environments is a significant challenge. This paper integrates two strategies that improve safety for industrial manipulators in uncertain conditions. First, software compliance in the task space is implemented using force feedback. End-effector compliance is vital for many tasks, such as interacting with humans or manipulating uncertain payloads. Beyond compliance, a collision detection algorithm detects collisions based on joint torque deviation from a dynamic model. Collisions can be detected at any point along the manipulator via loading or impulse anomalies. Joint torque data is typically noisy, and the accuracy of the robot dynamic model is limited, so an Extended Kalman Filter (EKF) was developed to improve the torque estimates. Experiments and demonstrations were performed using a commercially available 7DOF industrial robot. The EKF improved collision detection during unplanned contact tasks, and the method described here is hardware agnostic and extensible.

scholarly journals Use of Force Feedback Device in a Hybrid Brain-Computer Interface Based on SSVEP, EOG and Eye Tracking for Sorting Items

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7244
Author(s):  
Arkadiusz Kubacki
Keyword(s):  
Eye Tracking ◽  
Computer System ◽  
Force Feedback ◽  
Industrial Robot ◽  
Real Life ◽  
Feedback System ◽  
Human Organism ◽  
Special Role ◽  
Positioning Accuracy ◽  
The Real

Research focused on signals derived from the human organism is becoming increasingly popular. In this field, a special role is played by brain-computer interfaces based on brainwaves. They are becoming increasingly popular due to the downsizing of EEG signal recording devices and ever-lower set prices. Unfortunately, such systems are substantially limited in terms of the number of generated commands. This especially applies to sets that are not medical devices. This article proposes a hybrid brain-computer system based on the Steady-State Visual Evoked Potential (SSVEP), EOG, eye tracking, and force feedback system. Such an expanded system eliminates many of the particular system shortcomings and provides much better results. The first part of the paper presents information on the methods applied in the hybrid brain-computer system. The presented system was tested in terms of the ability of the operator to place the robot’s tip to a designated position. A virtual model of an industrial robot was proposed, which was used in the testing. The tests were repeated on a real-life industrial robot. Positioning accuracy of system was verified with the feedback system both enabled and disabled. The results of tests conducted both on the model and on the real object clearly demonstrate that force feedback improves the positioning accuracy of the robot’s tip when controlled by the operator. In addition, the results for the model and the real-life industrial model are very similar. In the next stage, research was carried out on the possibility of sorting items using the BCI system. The research was carried out on a model and a real robot. The results show that it is possible to sort using bio signals from the human body.

scholarly journals Development and Testing of a Methodology for the Assessment of Acceptability of LKA Systems

Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 47 ◽  
Author(s):  
Luca Salvati ◽  
Matteo d’Amore ◽  
Anita Fiorentino ◽  
Arcangelo Pellegrino ◽  
Pasquale Sena ◽  
...  
Keyword(s):  
Force Feedback ◽  
Feedback System ◽  
Operating Conditions ◽  
Experimental Methodology ◽  
Driving Safety ◽  
Steering Wheel ◽  
Human In The Loop ◽  
Automation Systems ◽  
Driving Stability ◽  
Lane Keeping

In recent years, driving simulators have been widely used by automotive manufacturers and researchers in human-in-the-loop experiments, because they can reduce time and prototyping costs, and provide unlimited parametrization, more safety, and higher repeatability. Simulators play an important role in studies about driver behavior in operating conditions or with unstable vehicles. The aim of the research is to study the effects that the force feedback (f.f.b.), provided to steering wheel by a lane-keeping-assist (LKA) system, has on a driver’s response in simulators. The steering’s force feedback system is tested by reproducing the conditions of criticality of the LKA system in order to minimize the distance required to recover the driving stability as a function of set f.f.b. intensity and speed. The results, obtained in three specific criticality conditions, show that the behaviour of the LKA system, reproduced in the simulator, is not immediately understood by the driver and, sometimes, it is in opposition with the interventions performed by the driver to ensure driving safety. The results also compare the performance of the subjects, either overall and classified into subgroups, with reference to the perception of the LKA system, evaluated by means of a questionnaire. The proposed experimental methodology is to be regarded as a contribution for the integration of acceptance tests in the evaluation of automation systems.

Development and Testing of a Telemanipulation System With Arm and Hand Motion

2000 ◽  
Author(s):  
Michael L. Turner ◽  
Ryan P. Findley ◽  
Weston B. Griffin ◽  
Mark R. Cutkosky ◽  
Daniel H. Gomez
Keyword(s):  
Force Feedback ◽  
Haptic Feedback ◽  
Industrial Robot ◽  
Robot Hand ◽  
Robot Arm ◽  
Task Execution ◽  
Hand Motion ◽  
Instrumented Glove ◽  
Simple Manipulation ◽  
Dexterous Robot Hand

Abstract This paper describes the development of a system for dexterous telemanipulation and presents the results of tests involving simple manipulation tasks. The user wears an instrumented glove augmented with an arm-grounded haptic feedback apparatus. A linkage attached to the user’s wrist measures gross motions of the arm. The movements of the user are transferred to a two fingered dexterous robot hand mounted on the end of a 4-DOF industrial robot arm. Forces measured at the robot fingers can be transmitted back to the user via the haptic feedback apparatus. The results obtained in block-stacking and object-rolling experiments indicate that the addition of force feedback to the user did not improve the speed of task execution. In fact, in some cases the presence of incomplete force information is detrimental to performance speed compared to no force information. There are indications that the presence of force feedback did aid in task learning.

Evidence of positive force feedback among hindlimb extensors in the intact standing cat

1995 ◽  
Vol 73 (6) ◽  
pp. 2578-2583 ◽  
Author(s):  
C. A. Pratt
Keyword(s):  
Force Feedback ◽  
Functional Organization ◽  
Force Plate ◽  
Feedback System ◽  
Implanted Electrodes ◽  
Golgi Tendon Organs ◽  
Ia Afferents ◽  
Extensor Muscles ◽  
Stimulation Of ◽  
Positive Force

1. The functional organization of heterogenic reflexes produced by activation of extensor force receptors (Golgi tendon organs) was studied in intact cats during stationary stance. Intramuscular stimulation (200 Hz, 20 ms) of hindlimb extensor muscles via chronically implanted electrodes was used to evoke weak muscle contractions and naturally activate Golgi tendon organ Ib afferents while cats stood unrestrained with each paw on a moveable triaxial force plate. 2. Intramuscular stimulation of every hindlimb extensor muscle tested in this study evoked excitatory responses that were widely distributed among hindlimb extensor muscles. Source and target specializations in the functional organization of this positive force feedback system were also observed. For example, stimulation of ankle extensors typically excited extensors and flexors at the ankle and hip (but not knee), whereas stimulation of hip extensors typically excited only extensors at all three joints. In addition, intramuscular stimulation of either lateral (LG) or medial (MG) gastrocnemius consistently inhibited soleus while exciting other extensors at the ankle and more proximal joints. 3. The electromyographic (EMG) reflex responses described above are attributed to the natural (via muscle contraction) activation of extensor group Ib afferents. Direct activation of intramuscular afferents by the stimulus was unlikely because there was no evidence that Ia afferents, which have the lowest electrical thresholds, were activated. Both the observed inhibition of the synergist, soleus, and the excitation of the antagonist, tibialis anterior, produced by gastrocnemius stimulation are opposite to the reflex effects that would be produced at the ankle by activation of gastrocnemius Ia afferents.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Method for the Detection of Tumor Blood Vessels in Neurosurgery Using a Gripping Force Feedback System

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5157
Author(s):  
Hiroki Yokota ◽  
Takeshi Yoneyama ◽  
Tetsuyou Watanabe ◽  
Yasuo Sasagawa ◽  
Mitsutoshi Nakada
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Force Feedback ◽  
Correlation Coefficients ◽  
Feedback System ◽  
Force Sensor ◽  
Robot System ◽  
Blood Vessel Detection ◽  
Operating Space ◽  
Gripping Force

Avoiding unnecessary bleeding during neuroendoscopic surgeries is crucial because achieving hemostasis in a narrow operating space is challenging. However, when the location of a blood vessel in a tumor cannot be visually confirmed, unintentional damage to the vessel and subsequent bleeding may occur. This study proposes a method for tumor blood vessel detection using a master–slave surgical robot system equipped with a force sensor in the slave gripper. Using this method, blood pulsation inside a tumor was detected, displayed as a gripping force wave, via the slave force sensor. The characteristics of gripping force due to blood pulsation were extracted by measuring the fluctuation of the force in real time. The presence or absence of blood vessels was determined on the basis of cross-correlation coefficients between the gripping force fluctuation waveform due to blood pulsation and model fluctuation waveform. Experimental validation using two types of simulated tumors (soft: E = 6 kPa; hard: E = 38 kPa) and a simulated blood vessel (E = 1.9 MPa, radius = 0.5 mm, thickness = 0.1 mm) revealed that the presence of blood vessels could be detected while gripping at a constant angle and during transient gripping.

Sign in / Sign up

Export Citation Format

Share Document