Piezoelectric inertial actuator with “forward-forward” motion mode

2021 ◽  
Vol 29 (6) ◽  
pp. 1356-1364
Author(s):  
Yi-li HU ◽  
◽  
Ying HU ◽  
Jian-ping LI ◽  
Jian-ming WEN ◽  
...  
Author(s):  
Ting Pan ◽  
Jiaqing Yan ◽  
Shenyun Zhou ◽  
Yingjie Cai ◽  
Congda Lu

Purpose The purpose of this paper is to propose the situation that the existing parking automated guided vehicle (AGV) has a single walking mode, a spin forward motion mode based on a dual steering wheel driven parking AGV. In this way, the AGV can complete the 180° spin of the AGV in the process of straight forward. Design/methodology/approach A spin forward kinematics model of the dual steering wheel AGV is established, and a motion controller of the dual steering wheel AGV is designed based on the principle of model predictive control to complete the path following the spin forward motion mode. Findings Computer simulations and laboratory tests were performed on this movement mode, which showed that the operation mode was feasible. It also verified that the mode can improve the handling efficiency, and also solved the problem that the parking space beside the wall could not be set and the site utilization was improved. Research limitations/implications The controller should be further improved to make the operation smoother and more accurate. Practical implications This mode has the applicability to the indoor logistics AGVs. In addition, it can improve the handling efficiency and also solved the problem that the storage space for goods beside the wall could not be set and the site utilization was improved. Social implications This method can solve the problem due to the increasing number of private cars and parking spaces are hard to find. It increases the number of parking spaces and improves the utilization rate of the site. In addition, it also saves people the time to find a parking space and reduces car exhaust emissions in the process. It follows the requirements of sustainable development. Originality/value The studies in this paper provide AGV with more ideas on the issue of improving handling efficiency and site utilization and also solves the problem of being unable to set parking spaces when parking against the wall. In addition, this model has applicability to indoor logistics AGV and plays the same role.


2014 ◽  
Vol 1 (2) ◽  
pp. 52-60
Author(s):  
V. Bulgakov ◽  
V. Adamchuk ◽  
H. Kaletnyk

The new design mathematical model of the sugar beet roots vibration digging-out process with the plowshare vibration digging working part has been created. In this case the sugar beet root is simulated as a solid body , while the plowshare vibration digging working part accomplishes fl uctuations in the longitudinal - vertical plane with the given amplitude and frequency in the process of work . The aim of the current research has been to determine the dependences between the design and kinematic parameters of the sugar beet roots vibra- tion digging-out technological process from soil , which provide the ir non-damage. Methods . For the aim ac- complishment, the methods of design mathematical models constructing based on the classical laws of me- chanics are applied. The solution of the obtained differential equations is accomplished with the PC involve- ment. Results . The differential equations of the sugar beet root’s motion in course of the vibration digging-out have been comprised . They allow to determine the admissible velocity of the vibration digging working part’s forward motion depending on the angular parameters of the latter. In the result of the computational simula- tion i.e., the solution of the obtained analytical dependence by PC, the graphic dependences of the admissible velocity of plowshare v ibration digging working part’s forward motion providing the extraction of the sugar beet root from soil without the breaking-off of its tail section have been determined. Conclusions . Due to the performed analytical research , it has been established that γ = 13 ... 16 ° , β = 20 ... 30 ° should be considered as the most reasonable values of γ and β angles of the vibration digging working part providing both its forward motion optimum speed and sugar beet root digging-out from the soil without damage . On the ground of the data obtained from the analytical rese arch, the new vibration digging working parts for the sugar beet roots have been designed; also the patents of Ukraine for the inventions have been obtained for them.


1999 ◽  
Author(s):  
Julien Bernard ◽  
George Lesieutre ◽  
Gary Koopmann
Keyword(s):  

Author(s):  
Qiang Cheng ◽  
Baobao Qi ◽  
Hongyan Chu ◽  
Ziling Zhang ◽  
Zhifeng Liu ◽  
...  

The combination of sliding/rolling motion can influence the degree of precision degradation of ball screw. Precision degradation modeling and factors analysis can reveal the evolution law of ball screw precision. This paper presents a precision degradation model for factors analysis influencing precision due to mixed sliding-rolling motion. The precision loss model was verified through the comparison of theoretical models and experimental tests. The precision degradation due to rolling motion between the ball and raceway accounted for 29.09% of the screw precision loss due to sliding motion. Additionally, the total precision degradation due to rolling motion accounted for 21.03% of the total sliding precision loss of the screw and nut, and 17.38% of the overall ball screw precision loss under mixed sliding-rolling motion. In addition, the effects of operating conditions and structural parameters on precision loss were analyzed. The sensitivity coefficients of factors influencing were used to quantitatively describe impact degree on precision degradation.


2021 ◽  
Vol 50 ◽  
pp. 100678
Author(s):  
Gabriele Franzese ◽  
Simone Silvestro ◽  
David A. Vaz ◽  
Ciprian Ionut Popa ◽  
Fabio Cozzolino ◽  
...  
Keyword(s):  

Author(s):  
Guangbo Hao ◽  
Xianwen Kong ◽  
Xiuyun He

A planar reconfigurable linear (also rectilinear) rigid-body motion linkage (RLRBML) with two operation modes, that is, linear rigid-body motion mode and lockup mode, is presented using only R (revolute) joints. The RLRBML does not require disassembly and external intervention to implement multi-task requirements. It is created via combining a Robert’s linkage and a double parallelogram linkage (with equal lengths of rocker links) arranged in parallel, which can convert a limited circular motion to a linear rigid-body motion without any reference guide way. This linear rigid-body motion is achieved since the double parallelogram linkage can guarantee the translation of the motion stage, and Robert’s linkage ensures the approximate straight line motion of its pivot joint connecting to the double parallelogram linkage. This novel RLRBML is under the linear rigid-body motion mode if the four rocker links in the double parallelogram linkage are not parallel. The motion stage is in the lockup mode if all of the four rocker links in the double parallelogram linkage are kept parallel in a tilted position (but the inner/outer two rocker links are still parallel). In the lockup mode, the motion stage of the RLRBML is prohibited from moving even under power off, but the double parallelogram linkage is still moveable for its own rotation application. It is noted that further RLRBMLs can be obtained from the above RLRBML by replacing Robert’s linkage with any other straight line motion linkage (such as Watt’s linkage). Additionally, a compact RLRBML and two single-mode linear rigid-body motion linkages are presented.


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