Computer-aided synthesis of spherical and planar 4R linkages for four specified orientations

Wang, Guangming; Zhang, Hao; Li, Xiaoyü; Wang, Jiabo; Zhang, Xiaohui; Fan, Genghua

doi:10.5194/ms-10-309-2019

Cited by 6 publications

(4 citation statements)

References 22 publications

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“…For the thirdorder mechanism, two in ection circles can be solved according to (9), so there are two solution cases, as shown in Figure 9(b). For the particular con guration 1/M = 0, two critical points P * 1 , P * 2 and two direction angles θ * 1 , θ * 2 of the corresponding side link A 0 A can be obtained according to (24), so there are two solution cases and no solution regions as shown in Figures 9(d (3) e mechanisms obtained by combining design variables in pairs are screened automatically. Check mechanism attributes item by item, as long as one does not conform to the constraints and the mechanism is unfeasible.…”

Section: Example Of Mechanism Synthesismentioning

confidence: 99%

“…Xu [23] proposed an approach to design largedisplacement straight-line mechanisms with rotational flexural joints based on a viewpoint that the straight-line motion is regarded as a compromise of rigid and compliant parasitic motion of a rotational flexural joint. Wang [24] introduced the calculation of circle and center points by the Burmester theory and developed a program package to find a satisfying linkage. Pickard [25] proposed an appropriate synthesis method for uncertainties present in the geometric parameters of linkages during dimensional synthesis.…”

Section: Introductionmentioning

confidence: 99%

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On the Solution of Region-Based Straight-Line Mechanism Design Optimization

Weixiang

Yang

Gong

et al. 2022

Mathematical Problems in Engineering

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A universal design method for synthesis problems of mechanisms that realize the approximate straight-line trajectory is presented in this paper. First, given the expected straight line and prescribed fixed pivots, a general mathematics model with angles as design parameters to determine the initial position of two side links is established, through which all infinite possible straight-line mechanisms are obtained. Then, kinematic constraints are imposed, including type, transmission angle, size, straightness, and defect. All feasible solution mechanisms that meet the constraints are calculated and can be expressed in solution regions. It is intuitive and comprehensive for designers to observe the distribution pattern of the solution. In the end, an optimal high-precision straight-line mechanism can be selected in the feasible solution regions by setting an optimization aim. The second-order osculating mechanism synthesis method can provide more solutions for designers, but designers can use the third-order osculating mechanism synthesis method when a higher straightness requirement is imposed. This method addresses the synthesis problem of this kind of mechanism for straight-line guidance and the problem of choosing an optimal solution from an infinite number of solutions.

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Section: Example Of Mechanism Synthesismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On the Solution of Region-Based Straight-Line Mechanism Design Optimization

Weixiang

Yang

Gong

et al. 2022

Mathematical Problems in Engineering

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“…The self-propelled cotton picker (high-power agricultural machinery) has frequent load fluctuations with a high transmission power, which requires the driver to frequently shift gears to adapt to load variations in accordance with the changing operating conditions. HMCVT (hydro-mechanical continuously variable transmission) realizes the coupling of hydraulic power flows and mechanical power flows through the differential planetary gear train (Ni et al, 2013;Zhu et al, 2017;Wang et al, 2019a;Zhang et al, 2014), enabling the HMCVT speed ratio to realize stepless speed changes in the stepped mechanical section. The range of speed variations of the equidistant type HMCVT complies with the adjustment of the self-propelled cotton picker in operating conditions.…”

Section: Introductionmentioning

confidence: 99%

Research on the HMCVT gear shifting smoothness of the four-speed self-propelled cotton picker

Bao

Zhao

et al. 2020

Mech. Sci.

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Abstract. To improve the HMCVT gear shifting smoothness of the self-propelled cotton picker, the quadratic orthogonal rotation test was carried out through the HMCVT test bench and control system with engine speed, clutch oil pressure, flow control valve, load torque, displacement ratio as the influencing factors while jerk, dynamic load coefficient, speed drop, weighted acceleration RMS, frictional work as the response indexes. The mathematical model between the response indexes and the influencing factors was established through the data processing software Design Expert 10. After the single factor and multi-factor experimental analyses, the parameters were optimized based on the response surface methodology to obtain the optimal parameters. The test was carried out on the HMCVT test bench with the optimized parameter combination. The engine output speed was 900 rpm, the clutch oil pressure was 3.5 MPa, the flow control valve was 4.9 L min−1, the load torque was 130 Nm and the displacement ratio was −0.93. The result was as follows: the jerk was 5.04 m s−3, the weighted acceleration RMS was 0.467, the speed drop was 20.32 rpm and the dynamic load coefficient was 12.16. This study provides reference for the smooth shifting of the self-propelled cotton picker, which is of a certain significance to promote the operation of the self-propelled cotton picker under multiple working conditions.

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“…A straight-line motion mechanism refers to one whose points occupy a portion of a trajectory that is approximately or precisely rectilinear (Vidosic and Tesar, 1967;Dijksman, 1976;Yu et al, 2013;Yin et al, 2019). Numerous researchers have worked on the synthesis theory and developed optimization methods for such mechanisms (Han et al, 2009;Han and Cao, 2018;Yang et al, 2011;Cui and Han, 2016). Chen et al (2013Chen et al ( , 2016 focused on the design and analysis of compliant Sarrus straight-line mechanisms, and developed several straight-line mechanisms with special performance (Chen et al, 2013(Chen et al, , 2016.…”

Section: Introductionmentioning

confidence: 99%

Synthesis Theory and Optimum Design of Four-bar Linkage with Given Angle Parameters

Yin

Huang

et al. 2019

Mech. Sci.

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Abstract. In this paper, a synthesis method is proposed for the 5-point-contact four-bar linkage that approximates a straight line with given angle parameters. The given parameters were the angles and the location of the Ball point. Synthesis equations were derived for a general Ball–Burmester point case, the Ball–Burmester point at an inflection pole, and the Ball point that coincided with two Burmester points, resulting in three respective groups of bar linkages. Next, taking Ball–Burmester point as the coupler point, two out of the three bar-linkage combinations were used to generate three four-bar mechanisms that shared the same portion of a rectilinear trajectory. Computation examples were presented, and nine cognate straight-line mechanisms were obtained based on the Roberts-Chebyshev theory. Considering that the given parameters were angles which was arbitrarily chosen, with the other two serving as the horizontal and vertical axes, so the solution region graphs of the solutions for three mechanism configurations were plotted. Based on these graphs, the distribution of the mechanism attributes was obtained with high efficiency. By imposing constraints, the optimum mechanism solution was straightforwardly identified by the designers. For the angular parameters prescribed in this paper, the solutions for three straight-line mechanism configurations were obtained, along with nine cognate straight-line mechanisms that shared the same portion of the rectilinear trajectory. All the fixed pivot installation locations and motion performances differed, thus providing multiple solutions to the trajectory of the synthesis of mechanisms.

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Computer-aided synthesis of spherical and planar 4R linkages for four specified orientations

Cited by 6 publications

References 22 publications

On the Solution of Region-Based Straight-Line Mechanism Design Optimization

On the Solution of Region-Based Straight-Line Mechanism Design Optimization

Research on the HMCVT gear shifting smoothness of the four-speed self-propelled cotton picker

Synthesis Theory and Optimum Design of Four-bar Linkage with Given Angle Parameters

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