• Journal of the Korean Society for Precision Engineering
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• v.32 no.4
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• pp.359-367
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• 2015

The forces and moments exerted on humanoid robot foot are important information for controlling or monitoring the robot. Multi-axis force/moment sensor can be installed under humanoid robot foot to measure forces and moments. The sensor should have large stiffness to support the robot weight and small size not to disturb the motion of the robot. In this paper, we designed a 6-aixs force/moment sensor which has good accuracy, large measuring range, and new compact structure. In addition, the proposed sensor is evaluated using analytical method and FEM(Finite Elements Method) method. Finally, it turned out that it has good performance.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1814-1819
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• 2005

This paper describes the development of a Stewart platform-based robot force sensor with distinctive structure of ball joints. The number of ball joints is only a half of the similar style sensors, so it is possible to reduce size and weight of the sensor. The structure of ball joint is described and discussed. Furthermore, we use strain gauges, but not liner voltage differential transformers, as sensing elements, in order to reduce size and weight of the sensor. It is also proposed that beams are replaced with pipes as sensing elements of the sensor. The ball joints and sensing elements with pipes can effectively reduce the error of the sensor. A geometric analysis model is also proposed. The external force and its moment can be measured with this model. Moreover, the performance of this sensor was tested. The test results conducted to evaluate the sensing capability of the sensor is reported and discussed.

• 한국기계연구소 소보
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• s.18
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• pp.67-74
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• 1988

The force sensor is essentially required in controlling robot manipulator in such applications as precise assembly of mechanical parts, deburring and polishing and various kinds of 6-axis force sensors are developed for these application. This paper presents the algorithm of horizontal assembly of circular cross-sectional workpiece using 3-axis force sensor and procedure to develop the sensor. The sensor is calibrated and tested using AID converter and 16 bit micro computer. The result is $\pm$0.03% FS of zero stability, 0.1%FS of linearity and $\pm$0.05% FS of resolution. The sensor will be used in the research of robot application such as assembly and deburring interfaced with micro computer based robot controller which is under development at the robotics lab.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.211-215
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• 2023

In this paper, the stability and effectiveness of the force control with a 6-axis compliance device are verified by performing comparative experiments with a commercial F/T sensor. The position/force control algorithm based on the Cartesian stiffness of a compliance device is briefly introduced and the design result of a 6-axis compliance device with F/T sensing is presented. The comparative experiments show that the force control using a compliance device is much more stable than that with rigid F/T sensor due to the enough compliance of a compliance device larger than robot positional resolution.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.5
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• pp.529-536
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• 2013

Most serious stroke patients have the paralysis on their wrists, and can't use their hands freely. But their wrists can be recovered by rehabilitation exercises. Recently, professional rehabilitation therapeutists help stroke patients exercise their wrists in hospital. But it is difficult for them to rehabilitate their wrists, because the therapeutists are much less than stroke patients in number. Therefore, the wrist twist-exercise rehabilitation robot that can measure the twist force of the patients' wrists is needed and developed. In this paper, the six-axis force/moment sensor was designed appropriately for the robot. As a test result, the interference error of the six-axis force/moment sensor was less than 0.85%. It is thought that the sensor can be used to measure the wrist twist force of the patient.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.285-293
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• 2017

Jump rope has two motions. It starts as hand motion and ends as jump motion. Therefore, two motions should be considered together to detect rotations accurately. But previous researches only consider one of the two motions as in push-up, sit-up, lift dumbbells etc, which results in inaccurate detection of rotations. In this paper, detection of rotation in jump rope using two motions through 6-axis accelerometer gyro sensor is proposed. Jump motion is detected using accelerometer sensor and hand motion is detected using gyro sensor. Also start point and end point of jump rope is detected using magnitude and standard deviation of accelerometer and gyro sensor values. The count of rotation is detected using y-axis of gyro sensor value. Y-axis of gyro sensor value indicate hand motion of jump rope motion. The usefulness of the proposed method is confirmed through experimental results.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.59-64
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• 2001

The necessity of six axis force-torque sensors have been increased in the field of automatic assembly, polishing and deburing using robotic manipulator recently. This paper presents a simple and compact elastic structure design of the six axis force-torque sensor with a cross-shaped structure and the expected deflection value was induced by theoretical method to design a six axis force-torque sensor and then this theoretical method was verified by comparing with the results using the Finite Element Method(FEM).

• International Journal of Control, Automation, and Systems
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• v.3 no.3
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• pp.469-476
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• 2005

Performance of a force-torque sensor is affected significantly by an error signal that is included in the sensor signal. The error sources may be classified mainly into two categories: one is a structural error due to inaccuracy of sensor body, and the other is a noise signal existing in sensed information. This paper presents a principle of 6-axis force-torque sensor briefly, a double-hole structure to be able to improve a structural error, and then a signal conditioning to reduce the effect of a noise signal. The validity of the proposed method is investigated through experimental study, which shows that SIN ratio is improved significantly in our experimental setup, and the sensor can be implemented cheaply with reasonable performance.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.11
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• pp.37-45
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• 2010

Stroke patients can't use their hands because of the paralysis of their fingers. Their fingers are recovered by rehabilitating training, and the rehabilitating extent can be judged by grasping a spherical object. At present, the used object in hospital is only a spherical object, and can't measure the force of fingers. Therefore, doctors judge the rehabilitating extent by touching and watching at their fingers. So, the spherical object measuring system which can measure the force of their fingers should be developed. In this paper, the finger-force measuring system with a six-axis force/moment sensor which can measure the spherical-object grasping force is developed. The six-axis force/moment sensor was designed and fabricated, and the force measuring device was designed and manufactured using DSP (digital signal processing). Also, the grasping force test of men was performed using the developed finger-force measuring system, it was confirmed that the average force of men was about 120N.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.146-151
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• 2001

The importance of sensing the force and torque with arbitrary direction and magnitude is becoming more crucial for robotic applications and manufacturing automations. Recently, several designs of a multi-axis force-torque sensor have been tried to sense this force and torque. This paper deals mainly with the signal processing of a six-axis force-torque sensor using cross-shaped elastic structures with circular holes. In this paper, we show principle of sensing force and torque, the signal processing methodology, and efficient methods of seeking strain gage positions in the sensor structure. The validity of the proposed method is shown via experiments.