The paper proposes a control system for bicycle robot based on a passivity-based method. Bicycle robot is a nonlinear, MIMO (multi input - multi output) system. The first input of bicycle robot is the steering torque and and the second input has a relation with the kinetic energy. Its two outputs are the velocity of the steering angle and the velocity of the rolling angle . Bicycle robot is shown to be a passivity system. Consider a control problem which the steering angle tracks a value of zero and the rolling angle tracks a value of zero in order that bicycle robot keeps its vertical balance. We use a new control signal so that the system is passivity with input và output y= , which are the velocity of the steering angle and the velocity of the rolling angle . Stabilization of the equilibrium point at origin uses a PI (proportional integral) passivity-based control. Simulation results are done with Simulink in MATLAB and have good results such as short settling time and small percentage of overshoot. The error of the steering angle comes to 0.01 after two seconds and the error of the rolling angle comes to 0.01 after two seconds. Stability analyses using the passivity theory show that the equilibrium point at origin is asymptotically stable in the case of PI passivity-based control because the system has a positive definite storage function Vb and the derivative of Vb is semi-negative definite and the system is zero-state observable.
Glass ionomer cement (GIC), a thermoplastic polymer, is toughed by ionic bonding is used in dentistry as a filling material. The glass-powder used has some disadvantages such as: poor strength and toughness, and instability in water. Therefore, the aim of this work is to enhance mechanical and fluoride release properties of the GICs by modifying ingredients. The results show that the compressive strength reached to from 60.5 to 86.2 MPa, the setting time met the ISO 9917-1:2007 quality standard. This also suggests that, in addition to 35% PAA in water with Mw of 100,000, 5% of Maleic acid and 5% Tartaric acid to produce GIC which can be used as suitable materials for improving its fluoride ion release over 28 days. The average diameter (dmean) of glass powder for GICs was 14.3 mm; S.P. Surface area was 10,358 cm2=cm3, improvement of liquid composition includes 35% PAA in water with Mw of 100,000, 5% of Maleic acid and 5% Tartaric acid. The compressive strength after curing 28-day reaches from 60.5 to 86.2 MPa and the setting time responds with ISO 9917-1:2007. In conclusion, it was found that the GIC can release fluoride ions (F-) for the during of the examination period.
Leucite, a potassium alumino-silicate (KAlSi2O6), is a very promising material for dental applications. It was initially introduced into dental porcelain compositions to adjust the thermal expansion coefficient of the ceramic to be similar to that of metal [1,2,11,12]. The mineral leucite was synthesized by melting the mixture of KNO3, Al(OH)3 and Cam Ranh sand in the fire of acetylene burner, which can increase the temperature to around 2000 – 2200oC. The obtained material has the following properties: bulk density ρ = 2,48g/cm3, phase transformation temperature at 642,5oC, thermal expansion coefficient in range of 30 to 642,5oC (of tetragonal) is 25,9.10-6.K-1, in range 642,5 to 946,8oC is 9,3.10-6.K-1 (of cubic).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.