scholarly journals Analysis and design of auto-adaptive leveling hydraulic suspension for agricultural robot

2021 ◽  
Vol 18 (5) ◽  
pp. 172988142110406
Author(s):  
Kai Hu ◽  
Wenyi Zhang ◽  
Bing Qi
Keyword(s):  
Mountain Areas ◽  
Load Pressure ◽  
Analysis And Design ◽  
Load Sensing ◽  
Sensing System ◽  
Walking Performance ◽  
High Control ◽  
Control Accuracy ◽  
Agricultural Robot

The application of agricultural robot in hilly and mountain areas faces several problems, such as bad walking performance, easy tilt, and low safety. The auto-adaptive leveling hydraulic suspension for the agricultural robot can help to eliminate some sort of problems. The design of such system is the main aim of the article. The hydraulic system with load-sensing system and its controlling model were established and then the load-sensing system was modeled and simulated in Advanced Modeling Environment for SIMulation. The optimal proportional–integral–derivative parameters were determined by the optimized algorithm. The simulation results illustrated that the inlet and outlet pressure difference of throttle and the flow rate through throttle are 42 bar and 29.65 L/min, respectively, all the time when the load pressure varies from 0 bar to 100 bar. The load-sensing system has good power follow-up and high control accuracy. And then the experimental bench of auto-adaptive leveling hydraulic suspension was researched and developed to verify the leveling performance. The experimental results demonstrate that auto-adaptive leveling hydraulic suspension can keep frame leveling dynamically on upslope, downslope, side slope, and continuous undulating road surface. The maximum errors of the pitch angle and the tilt angle are −0.93° and 0.97°. The feasibility of the designed hydraulic suspension was verified. The research methods in this article can provide theoretical basis for the design of other auto-adaptive leveling systems in hilly and mountain areas.

A double variable control load sensing system for electric hydraulic excavator

Energy ◽  
2021 ◽  
Vol 223 ◽  
pp. 119999
Author(s):  
Tianliang Lin ◽  
Yuanzheng Lin ◽  
Haoling Ren ◽  
Haibin Chen ◽  
Zhongshen Li ◽  
...  
Keyword(s):  
Hydraulic Excavator ◽  
Load Sensing ◽  
Sensing System ◽  
Variable Control ◽  
Control Load

scholarly journals Job demands & control among employees in Sweden aged 55-64 and labour market status 11 years later

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
K Farrants ◽  
K Alexanderson
Keyword(s):  
Labour Market ◽  
Old Age ◽  
Multinomial Logistic Regression ◽  
Job Demands ◽  
Job Control ◽  
Paid Work ◽  
Market Status ◽  
High Control ◽  
Labour Market Status

Abstract Background As discussions about extending working lives are ongoing, more knowledge is warranted on how psychosocial working conditions are associated with labour market status in older age. Aim Among employees aged 55-64 years, explore associations between job demands/control with their labour market status 11 years later, using a job exposure matrix (JEM). Methods A population-based prospective cohort study using nationwide register data. All 616,818 individuals in Sweden who in 2001 were in paid work and aged 55-64, were categorized using JEM into 9 groups, based on tertiles. They were followed up in 2012 regarding their labour market status (main income from: paid work, old-age pension, marginalised (no income/social assistance), sickness absence >183 net days, emigrated, dead) using multinomial logistic regression for odds ratios (OR) and 95% confidence intervals (CI), controlling for labour market status and sociodemographics in 2001. Analyses were stratified by sex. Results The majority (women: 84.9%, men: 80.3%) had main income from old-age pension at the 11-year follow-up; 4.7% from paid work (women: 3.9%, men: 5.6%). Those initially in jobs with high demands were less likely to be marginalised at follow-up (OR women high demands/medium control 0.51, CI 0.38-0.68, high demands/high control 0.68, CI 0.50-0.92; OR men high demands/medium control 0.55, CI 0.31-0.96, high demands/high control 0.47, CI 0.30-0.73). Those in occupations with low demands were less likely to be in paid work (OR women low demands/low control 0.56, CI 0.51-0.62, low demands/medium control 0.63, CI 0.58-0.69; OR men low demands/low control 0.56, CI 0.51-0.63, low demands/medium control 0.63, CI 0.58-0.69). Conclusions High job demands with high job control among people aged 55-64 in 2001 were associated with higher rate and OR of having main income from paid work in 2012, and high job demands regardless of level of job control were associated with less marginalisation. Key messages Levels of job demands when aged 55-64 were associated with labour market status 11 years later for women and men, while levels of job control were less so. High job demands were associated with a higher likelihood of being in paid work and lower likelihood of being marginalised at the end of follow-up.

scholarly journals Mobile educational follow-up application for patients with peripheral arterial disease

2019 ◽  
Vol 27 ◽  
Author(s):  
Cristiane Baldessar Mendez ◽  
Nádia Chiodelli Salum ◽  
Cintia Junkes ◽  
Lucia Nazareth Amante ◽  
Carlos Mauricio Lopes Mendez
Keyword(s):  
Risk Factors ◽  
Peripheral Arterial Disease ◽  
Signs And Symptoms ◽  
Arterial Disease ◽  
Pedagogical Content ◽  
Analysis And Design ◽  
Individualized Care ◽  
Technological Tool ◽  
Peripheral Arterial

ABSTRACT Objective: to describe the development of a prototype mobile educational application for nursing follow-up aimed at patients diagnosed with peripheral arterial disease. Method: a prototype-based technological production study. The construction followed the contextualized instructional design model using two steps: analysis and design and development. Results: the pedagogical content of the application was based on a survey of needs of patients with Peripheral Arterial Disease and treatments recommended in the literature. The prototype developed contained concepts, risk factors, signs and symptoms, treatment, importance of medications and their side effects, frequent doubts, necessary health care, and follow-up of patients by monitoring the evolution of the cicatricial process of lesions and possible complications, clarification of doubts and stimulus for continuation of treatment. Conclusion: the use of health applications is a technological tool with the potential to improve the follow-up of patients regarding the progress of the disease and self-care, monitoring of risk factors, co-participation of the patient in the treatment, family participation, as well as planning of individualized care, and cost reduction for the health system.

Demonstration of a Novel Smart Structural System for Pointing Control of Trusses

2016 ◽  
Author(s):  
Takeshi Shimada ◽  
Kosei Ishimura ◽  
Taro Kawano
Keyword(s):  
Feasibility Study ◽  
Large Scale ◽  
Control Mechanism ◽  
Displacement Sensor ◽  
Internal Displacement ◽  
Experimental Demonstration ◽  
Structural System ◽  
High Control ◽  
Pointing Control ◽  
Control Accuracy

We designed and developed a novel smart structural system for pointing control of large-scale support structures, such as trusses. The system consists of a pointing control mechanism, an internal displacement-sensor, and a controller. Remarkable points of our system are (1) artificial thermal expansion of truss members is utilized as linear actuators, (2) elastic hinges are applied instead of boll joints, and (3) the internal displacement-sensor which does not need external jigs and has high measuring accuracy is applied. In this paper, we conducted the feasibility study and the experimental demonstration. As a result of the feasibility study, the proposed pointing control mechanism can produce several hundred arcseconds of the rotational displacements within three minutes, therefore it has potential for using in practical operations. As a result of the experimental demonstration, we confirmed that the hysteresis of the pointing control mechanism can be kept sufficiently small due to the absence of the sliding parts, and has high control accuracy and followability (the error RMS value for a circle of the radius of 500 μm is 3.6 %).

Automobile Air-Conditioner Control System Based on STC12C5A60S2 Single-Chip Microcontroller

2012 ◽  
Vol 614-615 ◽  
pp. 635-639
Author(s):  
Shu Sheng Xiong ◽  
Lian Xie ◽  
Sheng Kai Zhou ◽  
Xiao Shuai Ren ◽  
Jin Xu
Keyword(s):  
Control System ◽  
Software Design ◽  
Hardware Design ◽  
Conversion Function ◽  
Air Conditioner ◽  
Single Chip ◽  
Important Indicator ◽  
Automobile Air Conditioner ◽  
High Control ◽  
Control Accuracy

Recent years, automobile air-conditioner control system is particularly important as the automobile air-conditioner is becoming an important indicator to measure the comfort of a car. This paper introduces the hardware and software design of the system based on STC12C5A60S2 microcontroller.The hardware design part includes the circuits design of motor and fan, and the software design part describes the way to realize the modes conversion function. Experiments show that the automobile air-conditioner system can reach high control accuracy and it's practical.

Impact of Flow Force to the Constant Flow Characteristic of Load Sensing Pump

2010 ◽  
Author(s):  
Chong Ma ◽  
Xiaowu Kong
Keyword(s):  
Steady State ◽  
Control Valve ◽  
Test Results ◽  
Steady State Flow ◽  
Load Pressure ◽  
Load Sensing ◽  
State Flow ◽  
Throttle Valve ◽  
Output Flow ◽  
The Impact

Aiming at studying the impact of steady-state flow force to YL-56 load sensing pump and how to reduce the effects of flow force on control valve spool, the factors of steady-state flow force were analyzed using CFD software FLUENT, and virtual prototype of load sensing pump was developed to study its characteristics. Compared with the effect of using position-controlled proportional solenoid to drive the throttle valve in simulation, the use of force-controlled proportional solenoid could suppress the impact of steady-state flow force much better, and the problem that the output flow increased when load pressure rose was solved. The experiment test results indicate that using force-controlled proportional solenoid in throttle valve can decrease the impact of steady-state flow force quite well.

scholarly journals A smart load-sensing system using standardized mechano-luminescence measurement

2015 ◽  
Vol 23 (5) ◽  
pp. 6073 ◽  
Author(s):  
Kee-Sun Sohn ◽  
Min Young Cho ◽  
Minseuk Kim ◽  
Ji Sik Kim
Keyword(s):  
Load Sensing ◽  
Sensing System ◽  
Luminescence Measurement

Performances analysis of a novel load-sensing hydraulic system with overriding differential pressure control

2016 ◽  
Vol 231 (23) ◽  
pp. 4331-4343 ◽  
Author(s):  
Hu Quanyi ◽  
Zhang Hong ◽  
Tian Shujun ◽  
Qin Xuxin
Keyword(s):  
Hydraulic System ◽  
Graph Model ◽  
Pressure Control ◽  
Bond Graph ◽  
Differential Pressure ◽  
Operating Conditions ◽  
Control Mode ◽  
Variable Pressure ◽  
Load Sensing ◽  
Sensing System

The traditional load-sensing hydraulic system is an energy-saving fluid power transmission, which supply “on-demand” flow at a prescribed pressure margin greater than the highest load pressure of the system. In this paper, a novel load-sensing system that has a variable pressure margin through overriding differential pressure control via integrating an electro-proportional three-way type pressure reducing valve into the hydro-mechanical load-sensing valve is proposed. Also, a bond graph model taking into account the dynamic characteristics of load-sensing valve and load-sensing path is constructed, and three group experiments are performed to verify the validation of the model. Based on the bond graph model, a series of theoretical simulations are carried out to prove that the proposed Load-Sensing system enables a satisfactory balance between energy efficiency and rapid dynamic response over a wide range of operating conditions. In addition, due to overriding differential pressure control, mode selection and power limit regulation can also be achieved.

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