A Mathematical Model Including Mechanical Structure, Hydraulic and Control of LHDS

Robotica ◽  
2021 ◽  
pp. 1-16
Author(s):  
Guoliang Ma ◽  
Kaixian Ba ◽  
Zhiwu Han ◽  
Zhengguo Jin ◽  
Bin Yu ◽  
...  

SUMMARY In this paper, mathematical models of kinematics, statics and inverse dynamics are derived firstly according to the mechanical structure of leg hydraulic drive system (LHDS). Then, all the above models are integrated with MATLAB/Simulink to build the LHDS simulation model, the model not only considers influence of leg dynamic characteristics on hydraulic system but also takes into account nonlinearity, variable load characteristics and other common problems brought by hydraulic system, and solves compatibility and operation time which brought by using multiple software simultaneously. The experimental results show the simulation model built in this paper can accurately express characteristics of the system.

2013 ◽  
Vol 416-417 ◽  
pp. 845-848
Author(s):  
Qiang Rong

The application of hydraulic drive as well as control technology to construction machinery control as well as operating system has been very common. In this paper, network control system is briefly introduced first, and then the computer controls of vehicle and construction machinery hydraulic system are discussed respectively from the new methods for the motion control and integration of drive and operating system, and the operating and control system design of beam lifting machine DJY200.


2014 ◽  
Vol 630 ◽  
pp. 375-382 ◽  
Author(s):  
Daniel Himr ◽  
Vladimir Haban

A pumping station in a fuel storage suffered from pressure pulsations in a petrodiesel pipeline. Check valves protecting the station against back flow made a big noise when disc hit a seat. Due to employees complaints we were asked to solve the problem, which could lead to serious mechanical problems. Pressure measurement in the pipeline showed great pulsations, which were caused by self-excited oscillation of control valves at the downstream end of pipeline. The operating measurement did not catch it because of too low sampling frequency. One dimensional numerical model of the whole hydraulic system was carried out. The model consisted of check valve, pipeline and control valve, which could oscillate, so it was possible to simulate the unsteady flow. When the model was validated, a vessel with nitrogen was added to attenuate pressure pulsations. According to the results of numerical simulation, the vessel was installed on the location. Subsequent measurement proved noticeably lower pulsations and almost no noise.


Author(s):  
Dheeraj Agarwal ◽  
Linghai Lu ◽  
Gareth D. Padfield ◽  
Mark D. White ◽  
Neil Cameron

High-fidelity rotorcraft flight simulation relies on the availability of a quality flight model that further demands a good level of understanding of the complexities arising from aerodynamic couplings and interference effects. One such example is the difficulty in the prediction of the characteristics of the rotorcraft lateral-directional oscillation (LDO) mode in simulation. Achieving an acceptable level of the damping of this mode is a design challenge requiring simulation models with sufficient fidelity that reveal sources of destabilizing effects. This paper is focused on using System Identification to highlight such fidelity issues using Liverpool's FLIGHTLAB Bell 412 simulation model and in-flight LDO measurements from the bare airframe National Research Council's (Canada) Advanced Systems Research Aircraft. The simulation model was renovated to improve the fidelity of the model. The results show a close match between the identified models and flight test for the LDO mode frequency and damping. Comparison of identified stability and control derivatives with those predicted by the simulation model highlight areas of good and poor fidelity.


Author(s):  
Hamid Khakpour Nejadkhaki ◽  
John F. Hall ◽  
Minghui Zheng ◽  
Teng Wu

A platform for the engineering design, performance, and control of an adaptive wind turbine blade is presented. This environment includes a simulation model, integrative design tool, and control framework. The authors are currently developing a novel blade with an adaptive twist angle distribution (TAD). The TAD influences the aerodynamic loads and thus, system dynamics. The modeling platform facilitates the use of an integrative design tool that establishes the TAD in relation to wind speed. The outcome of this design enables the transformation of the TAD during operation. Still, a robust control method is required to realize the benefits of the adaptive TAD. Moreover, simulation of the TAD is computationally expensive. It also requires a unique approach for both partial and full-load operation. A framework is currently being developed to relate the TAD to the wind turbine and its components. Understanding the relationship between the TAD and the dynamic system is crucial in the establishment of real-time control. This capability is necessary to improve wind capture and reduce system loads. In the current state of development, the platform is capable of maximizing wind capture during partial-load operation. However, the control tasks related to Region 3 and load mitigation are more complex. Our framework will require high-fidelity modeling and reduced-order models that support real-time control. The paper outlines the components of this framework that is being developed. The proposed platform will facilitate expansion and the use of these required modeling techniques. A case study of a 20 kW system is presented based upon the partial-load operation. The study demonstrates how the platform is used to design and control the blade. A low-dimensional aerodynamic model characterizes the blade performance. This interacts with the simulation model to predict the power production. The design tool establishes actuator locations and stiffness properties required for the blade shape to achieve a range of TAD configurations. A supervisory control model is implemented and used to demonstrate how the simulation model blade performs in the case study.


2021 ◽  
Author(s):  
R.V. Yudin ◽  
◽  
R.N. Puzakov ◽  

During the movement of the tractor on the uneven terrain, there are fluctuations that cause jumps of the working fluid in the hydraulic system and high dynamic loads. The solution to this problem is the use of an energy-saving hydraulic drive with a hydraulic accumulator and a system of aggregates this leads to increased efficiency and increased productivity of skidding grippers. A mathematical model of working processes with an energy-saving hydraulic drive is compiled.


2016 ◽  
Vol 1 (1) ◽  
pp. 20
Author(s):  
Elvira Handayani

Jambi city is one of the cities that began to develop on the island of Sumatra in the field of infrastructure and the economy, so development is one activity that is enhanced by the local government in the framework of the welfare and prosperity of the people of Jambi. In the process of development is very common problems causing delays in work, many factors causing delays become very common problem faced by the parties involved, especially the Contractor which act as implementers.From the research the factors causing delays in construction work in the city of Jambi as perceived by the contractor, a number of conclusions, among others:Factors Materials and Materials obtain a total score of 7.18,Environmental Factors obtain a total score of 5.96,Financial Factor obtain a total score of 5.99,Factors Changes obtain a total score of 6.95,The Labor get highest total score is 7.29,Factors and Control Time to get a total score of 5.93,Factors Hardware obtain a total score of 7.15


2021 ◽  
Vol 12 (1) ◽  
pp. 38-55
Author(s):  
Nur Asma

The common problems faced by students in English speaking are anxiety and the lack of confidence and ideas. This research was conducted to determine the relevant factors and to provide a solution by using the smartphone video camera. To obtain the data in this research, experimental research was performed inside and outside the classroom with a series of treatments and a questionnaire sheet as the instrument. The data were analyzed using a model proposed by Smeda, Dakich, and Sharda (2014) and a Likert scale questionnaire, which was adapted from Spratt, Humphreys, and Chan (2002). The result from the test showed a significant difference between the experimental and control classes as the carried t-test presented the score of -8.36, which was out of the limit (between -1.96 and 1.96). Another result was the students developed positively which was shown by: the anxiety tends to decrease as they were given time before performing thus prepared better, their self-confidence was increased and challenged by using the smartphone video camera method due to the application of innovation in the speaking class. The conclusion of this research is lecturer needs to apply new methods, one of which is using a smartphone application.


Sign in / Sign up

Export Citation Format

Share Document