Multi-objective optimization and simulation of novel working mechanism for face-shovel excavator

Abstract

In order to improve the working performance of the mining excavators, a new type of hydraulic excavator working device is proposed. The proposed excavator working device possesses main advantages of the Tri-Power structure, whereas the kinematic and dynamic analysis can be greatly simplified. In this paper, the kinematic model and tool force model of the new working device are established, and the working performance simulation is conducted. Simulation results show that the new device has excellent performance of level crowding, translational lifting and tool force, indicating that the proposed working device is feasible. After that, multi-objective optimization is designed based on intelligent optimization algorithm. Compared with performance before optimization, all the concerned objectives are improved, including the tool force, level crowding and translational lifting performance. The optimization result has the important reference for the design and application of the new type face-shovel excavator.

Appendix

Meaning of partial variables

$x_{0} ,y_{0}$:	Coordinates of point P in coordinate system $\{ xOy\}$	$x_{1} ,y_{1}$:	Coordinates of point P in coordinate system $\{ x_{1} Oy_{1} \}$
$x_{2} ,y_{2}$:	Coordinates of point P in coordinate system $\{ x_{2} O_{2} y_{2} \}$	$x_{3} ,y_{3}$:	Coordinate of point P in coordinate system $\{ x_{3} O_{3} y_{3} \}$
$d_{1} ,d_{2}$:	Lengths of the boom and arm	$\delta$:	The bucket attitude angle
$\Phi_{1}$:	The angle between the tangent line of bucket teeth and $x_{3}$ axis	$F_{{{\text{A}}\tau 1}}$:	The tool force provided by arm cylinders

$F_{{{\text{A}}\tau 2}}$:	The tool force limited by locking ability of bucket cylinder	$F_{{{\text{A}}\tau 3}}$:	The tool force limited by locking ability of boom cylinder
$F_{{{\text{A}}\tau 4}}$:	The tool force limited by machine slippage	$F_{{{\text{A}}\tau 5}}$:	The tool forces limited by tipping forward
$F_{{{\text{A}}\tau 6}}$:	The tool forces limited by tipping backward	$x_{D}$:	The horizontal axis value of point D, others are the same
$l_{{O_{2} P}}$:	The distance between $O_{2}$ and P, others are the same	$e_{22}$:	Arm of arm cylinder force toward $O_{2}$
$e_{32}$:	Arm of bucket cylinder force toward $O_{2}$	$G_{22}$:	The weight of arm cylinders
$G_{33}$:	The weight of bucket cylinders	$F_{{{\text{A}}\tau }}$:	The theoretical arm cylinder tool force
$\overline{\delta }$:	The average value of $\delta$	$F_{{{\text{B}}\tau }}$:	The theoretical bucket cylinder tool force
$R_{\max }$:	The maximum digging radius	$H_{\max }$:	The maximum digging height
$\eta_{1} ,\eta_{2}$:	Ratios of the arm cylinder or bucket cylinder giving full play	$C^{^{\prime}}$:	The vertical foot of C on the axis of the arm
$D_{\max }$:	The maximum digging depth	S:	The maximum crowding length on the level ground
$c_{3}$:	Design requirement of digging height	$c_{4}$:	Design requirement of digging radius
$c_{5}$:	Design requirement of digging depth	$c_{6}$:	Design requirement of crowding length
$c_{7}$:	Design requirement of arm tool force	$c_{8}$:	Design requirement of bucket tool force