Handling stability margin analysis of distributed wire-controlled vehicle: A fusion method of phase plane and dissipated energy

Although the distributed wire-controlled vehicle offers numerous advantages, the increased degrees of freedom introduce potential challenges regarding stability. Aiming at the limited reports on the influence of rear wheel steering angle on the handling stability margin of vehicle, the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>v</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> </mml:mrow> </mml:msub> <mml:mo>−</mml:mo> <mml:mi>ω</mml:mi> </mml:mrow> </mml:math> phase plane method and the dissipated energy method are employed for stability analysis. Firstly, the constrains in the direction of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>v</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>ω</mml:mi> </mml:mrow> </mml:math> on the phase plane are determined considering the maximum rear wheel steering angle. Secondly, the influences of road adhesion coefficient, longitudinal speed, front wheel steering angle and rear wheel steering angle on the stability region are analyzed. Then a parameter fitting method is applied to adaptively adjust the boundary of the stability region in response to changes in vehicle state parameters and driving conditions. After that, the mapping relationship between the dissipated energy and vehicle stability is studied, and the comprehensive handling stability margin analysis method is obtained by projecting the distribution of the dissipated energy to the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>v</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> </mml:mrow> </mml:msub> <mml:mo>−</mml:mo> <mml:mi>ω</mml:mi> </mml:mrow> </mml:math> phase plane through the gradient layering theory and the contour projection theory. Finally, the stability region divided by the comprehensive handling stability margin analysis method is verified, and the results show that the divided stability region is more accurate.