scholarly journals Payload Identification and Gravity/Inertial Compensation for Six-Dimensional Force/Torque Sensor with a Fast and Robust Trajectory Design Approach

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 439
Author(s):  
Jinjun Duan ◽  
Zhouchi Liu ◽  
Yiming Bin ◽  
Kunkun Cui ◽  
Zhendong Dai
Keyword(s):  
Force Control ◽  
Inertial Force ◽  
Least Square Method ◽  
Force Sensor ◽  
Rapid Identification ◽  
Least Square ◽  
Trajectory Design ◽  
Identification Algorithm ◽  
Torque Sensor ◽  
Compensation Algorithm

In the robot contact operation, the robot relies on the multi-dimensional force/torque sensor installed at the end to sense the external contact force. When the effective load and speed of the robot are large, the gravity/inertial force generated by it will have a non-negligible impact on the output of the force sensor, which will seriously affect the accuracy and effect of the force control. The existing identification algorithm time is often longer, which also affects the efficiency of force control operations. In this paper, a self-developed multi-dimensional force sensor with integrated gravity/inertial force sensing function is used to directly measure the resultant force. Further, a method for the rapid identification of payload based on excitation trajectory is proposed. Firstly, both a gravity compensation algorithm and an inertial force compensation algorithm are introduced. Secondly, the optimal spatial recognition pose based on the excitation trajectory was designed, and the excitation trajectory of each joint is represented by a finite Fourier series. The least square method is used to calculate the identification parameters of the load, the gravity, and inertial force. Finally, the experiment was verified on the robot. The experimental results show that the algorithm can quickly identify the payload, and it is faster and more accurate than other algorithms.

scholarly journals Optimized Design and Calibration of the Triaxis Induction Magnetometer with Crosstalk and Nonorthogonality Compensation

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Hongyu Shi ◽  
Yanzhang Wang ◽  
Jun Lin
Keyword(s):  
Theoretical Analysis ◽  
Magnetic Flux ◽  
Least Square Method ◽  
Error Component ◽  
Least Square ◽  
Optimized Design ◽  
Frequency Dependent ◽  
Compensation Algorithm ◽  
Sensor Configuration ◽  
Dependent Error

An optimized triaxis induction magnetometer has been designed and calibrated to minimize the influences from the nonorthogonality and the magnetic flux crosstalk. Utilizing the nonlinear least square method, contributions due to the nonorthogonal assembly of three transducers are cancelled. The magnetic flux crosstalk is a frequency-dependent error component in the calibration of the triaxis induction magnetometer. Influences from the assembly density, the frequency, and the feedback amount are analyzed theoretically, and an optimized sensor configuration which has a smaller crosstalk is achieved. Moreover, a mathematical compensation algorithm has also been utilized to suppress the residues crosstalk ulteriorly. To validate the theoretical analysis, a triaxis induction magnetometer was manufactured and the experiment setup has also been built. The experiment results show that the cross-outputs of the transverse induction magnetometers have been significantly decreased about two orders, indicating that the proposed method is applicable for the triaxis induction magnetometer.

A Momentum-Based Algorithm for Identifying the Inertia Properties of a Human Body: A Preliminary Study

2010 ◽  
Author(s):  
Qi Lu ◽  
Ou Ma
Keyword(s):  
Human Body ◽  
Measurement Errors ◽  
Equations Of Motion ◽  
Least Square Method ◽  
Internal Force ◽  
Momentum Equation ◽  
The Body ◽  
Least Square ◽  
Identification Algorithm ◽  
Force Data

The body segment parameters (BSP) of a human body are critical information for modeling, simulating, and understanding human dynamics. The determination of BSPs of human bodies has received increasing attention in biomechanics, sport science, ergonomics, rehabilitation and other fields. This paper presents a momentum-based identification algorithm for dynamically estimating the BSPs of a human body. The human body is modeled as a multibody dynamical system, and the momentum equation of the system can be derived by applying the principle of impulse and momentum. It is possible to formulate the momentum equations corresponding to a set of experiment tests into a linear regression form with respect to the unknown BSPs, which then can be solved using the least square method or other methods. The momentum-based algorithm requires inputting position, velocity, and external force data only. Since acceleration and all the internal force data is not needed, the algorithm is less demanding on measurements and is also less sensitive to measurement errors. As a result, it is practically more appealing than the algorithms depending on the equations of motion. The paper presents the momentum-based inertia identification algorithm along with a simulation study of the algorithm using a simplified trunk-leg model representing a main portion of a human body.

A Study of Flexible Force Control Method on Robotic Assembly for Spacecraft

2014 ◽  
Vol 681 ◽  
pp. 79-85 ◽  
Author(s):  
Li Jian Zhang ◽  
Rui Qin Hu ◽  
Wang Min Yi ◽  
Hao Fu ◽  
Lai Ying Tang
Keyword(s):  
Force Control ◽  
Production Efficiency ◽  
Control Method ◽  
Robotic Assembly ◽  
Gravity Compensation ◽  
Torque Sensor ◽  
Improve Production ◽  
Compensation Algorithm ◽  
Input Parameters ◽  
Improve Production Efficiency

For complex spacecraft assembly conditions, how to play effective and flexible robotic characteristics, and improve production efficiency, is the problem needed to solve.this paper presents a flexible force control method on robotic assembly: a 6-axis force/torque sensor is mounted between tools and the end of robots, the operator operates the load by hands directly, and the system can obtain the force/torque information caused by operator’s hands through gravity compensation algorithm, then the force/torque information is used as input parameters to control the robots moving with the hands. The detailed scheme and algorithms are presented in this paper.

Parameter Identification Based on Nonlinear Observer for Mechanical Systems

2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Patricio Ordaz ◽  
Miguel Ramírez ◽  
Liliam Rodríguez ◽  
Carlos Cuvas ◽  
Hugo Romero ◽  
...  
Keyword(s):  
Parameter Identification ◽  
State Estimation ◽  
Finite Time ◽  
Mechanical Systems ◽  
Least Square Method ◽  
Least Square ◽  
Nonlinear Observer ◽  
Underactuated System ◽  
Identification Algorithm ◽  
Double Pendulum

Abstract This paper deals with the parameter identification problem for nonlinear mechanical systems based on state estimation. Here, the concept of Sliding Mode Observer for finite time state estimation and the Least-Square Method for parameter identification have been combined; thus, guaranteeing that the estimated state converges to the real one in a finite time. The asymptotic parameter identification is performed by applying the Least-Square approach, minimizing the so-called joint uncertainty; in this process, a specific persistent excitation condition is introduced to guarantee the effectiveness of the proposed identification algorithm. With the proposed approach and some considerations, the algorithm is capable of estimating friction coefficients and inertia moments, within a narrow time-window. Finally, the performance of the identification algorithm designed in this paper is tested on a real-time underactuated system, specifically the double pendulum on a cart platform. Furthermore, a successful benchmarking between the algorithm herein and the traditional least-square method is reported.

scholarly journals Carbon Dioxide Sensor Module Based on NDIR Technology

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 845
Author(s):  
Libing Zhou ◽  
Yaoyi He ◽  
Qing Zhang ◽  
Lei Zhang
Keyword(s):  
Light Propagation ◽  
Detection System ◽  
Coupling Efficiency ◽  
Least Square Method ◽  
Least Square ◽  
Compensation Algorithm ◽  
Dual Channel ◽  
Sensor Module ◽  
Gas Chamber ◽  
Channel Type

In this paper, a gas detection system with an environmental compensation algorithm based on nondispersive infrared (NDIR) technology was designed. The prepared infrared pyroelectric detector was a dual-channel type based on the lithium tantalate (LiTaO3) wafer. The design of the optical gas chamber adopted a combination of two ellipsoids and a spherical top surface, which not only enhanced the coupling efficiency of the light propagation but also facilitated the miniaturization of the sensor module. In addition to this, a temperature and humidity compensation algorithm based on the least square method was proposed to make the measurement accuracy up to ±0.9% full scale (FS).

Online Identification with Least Square Method for Pseudo-Dynamic Tests

2011 ◽  
Vol 250-253 ◽  
pp. 2455-2459 ◽  
Author(s):  
Tao Wang ◽  
Bin Wu ◽  
Jian Zhang
Keyword(s):  
Good Accuracy ◽  
Least Square Method ◽  
Least Square ◽  
Identification Algorithm ◽  
Dynamic Tests ◽  
Online Identification ◽  
Buckling Restrained Brace ◽  
Line Identification ◽  
Negative Effect ◽  
On Line

Numerical substructures adopt predetermined hysteretic models for conventional substructure testing (CST). It is difficult to achieve accurate results in CST due to errors from modelling of numerial substructures. To diminish the negative effect caused by the assumed restoring model, online identification with least square method using experimental data was adopted to update the model of numerical substructure. The effectiveness of least square method are verified with pseudo-dynamic substructure testing for single story frame with a buckling-restrained brace. The results indicate that the on-line identification algorithm based least square method has good accuracy, stability, and efficiency.

Research on a Kind of Quick Background Motion Compensation Algorithm Based on BRISK Operator

2014 ◽  
Vol 668-669 ◽  
pp. 1178-1181 ◽  
Author(s):  
Yan Min Lei ◽  
Zhi Bin Feng ◽  
Shu Jiao Ji ◽  
Xiao Xue Xing
Keyword(s):  
Real Time ◽  
Motion Compensation ◽  
Video Sequence ◽  
Interpolation Method ◽  
Motion Vector ◽  
Least Square Method ◽  
Least Square ◽  
Compensation Algorithm ◽  
Time Problem ◽  
Background Motion

In order to solve the real-time problem in the background motion compensation in video sequence, a kind of quick background motion compensation algorithm based on BRISK operator has been proposed in this paper. Firstly, feature points of two adjacent frames images was extracted and matched by using BRISK operator. Secondly, the motion vector of the neighboring frames images was calculated by using the least square method (LSM). Lastly, the video sequences were compensated by using bilinear interpolation method. The simulation results show that real-time can arrive at ms grade and meet the requirement of background motion compensation.

Direct Assessment of Effective Renal Plasma Flow from Renoscintigraphy with a Gamma Camera and an On-Line Computer

1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma
Keyword(s):  
Count Rate ◽  
Renal Plasma Flow ◽  
Early Period ◽  
Least Square Method ◽  
Least Square ◽  
Uptake Coefficient ◽  
Positive Linear Correlation ◽  
On Line ◽  
Best Fit ◽  
Plasma Activity

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the peak in the renoscintigraphic curve divided by the integral of the count-rate curve over the "blood"-ROI. A procedure for normalization of both curves against each other was also developed. The total kidney clearance of the hippurate was determined from the function of plasma activity concentration vs. time after a single injection; the determinations were made at 5, 10, 15, 20, 30, 45, 60, 75 and 90 min after intravenous administration of 131I-o-hippurate and the best-fit curve was obtained by means of the least-square method. When the UC was related to the absolute value of the clearance a positive linear correlation was found (r = 0.922, ρ > 0.99). Using this regression equation the clearance could be estimated in reverse from the uptake coefficient calculated solely on the basis of the renoscintigraphic curves without blood sampling. The errors of the estimate are compatible with the requirement of a fast appraisal of renal function for purposes of clinical diagknosis.

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