Vehicle Dynamics Modeling and Control of the TowPlow, A Stee(3)

Figure 5.5

Figure 5.6

Figure 5.7

Figure 5.8

Figure 5.9 Schemes of the snow plows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75Longitudinal snow resistant forces of the plows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76Lateral snow resistant forces of the plows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77Driver model – control scheme of the driving/braking torque . . . . . . . . . . . . . . . . . . . . 79Driver model – control scheme of the tractor steering angle . . . . . . . . . . . . . . . . . . . . . . 79Figure 5.10 Simulation results of the TowPlow running straight with and without driver model . . . 82Figure 5.11

Figure 5.12

Figure 5.13

Figure 5.14

Figure 5.15

Figure 6.1

Figure 6.2

Figure 6.3

Figure 6.4

Figure 6.5

Figure 6.6

Figure 6.7

Figure 6.8

Simulation results of deploying trailer plow and cornering . . . . . . . . . . . . . . . . . . . . . . . Simulation results of slalom, up and down hill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulation results of braking on a snow packed road (μ0 = 0.4) . . . . . . . . . . . . . . . . . . . Simulation results of split friction coefficient braking – tractor on a wet road (μ0 = 0.6) and trailer on a snow packed road (μ0 = 0.4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulation results of split friction coefficient braking – tractor on a snow packed road (μ0 = 0.4) and trailer on a yet road (μ0 = 0.6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Locus of the eigenvalues of the controlled system with varying longitudinal velocity . . LQR control scheme for the active steering of the trailer axle . . . . . . . . . . . . . . . . . . . . Cornering simulation results of the active trailer steering control . . . . . . . . . . . . . . . . . . PI control scheme for the active steering of the trailer axle . . . . . . . . . . . . . . . . . . . . . . PI control scheme for the active steering of the trailer axle . . . . . . . . . . . . . . . . . . . . . . Slalom, up and down hill simulation results of the active trailer steering control . . . . . . Split friction coefficient simulation results of the active trailer steering control - tractor on a wet road (μ0 = 0.6) and trailer on a snow packed road (μ0 = 0.4) . . . . . . . . . . . . . . Split friction coefficient simulation results of the active trailer steering control - tractor on a snow packed road (μ0 = 0.4) and trailer on a wet road (μ0 = 0.6) . . . . . . . . . . . . . . 83848687889293949596979899

List of Tables

Table 2.1 Vehicle parameters for kinematic analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 3.1 Vehicle parameters for stability analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 4.1 Parameters for tire friction calculation [26] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 4.2 Vehicle parameters for model validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table 5.1 Plow parameters for the snow resistance calculation [30, 31] . . . . . . . . . . . . . . . . . . . . . Table 5.2 Vehicle parameters for dynamic simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Chapter 1

Introduction

1.1 Background

The snow removal operation is an important highway maintenance operation during the winter season. It is also a hazardous operation that requires significant budget and labor. To clear the whole road width for multi-lane roadways, typically, the operation has been accomplished by several snowplows forming a trapezoidal formation, called ‘gang plowing’.

A novel type of snowplow, the TowPlow (Figure 1), has been invented lately to allow highway agencies to reduce their budget for the winter operations by enhancing the clearing capacity of a single snowplow vehicle. The TowPlow consists of a conventional snowplow vehicle, referred to as the tractor henceforth, which tows a steerable trailer with a moldboard. The trailer is equipped with steerable axles so that the trailer can be steered up to 30 degrees with respect to the tractor. The hydraulic rams connected to the tractor’s hitch also assist the control of the trailer. The combination of the front plow of the towing snowplow and the trailer-equipped plow is able to clear a path up to approximately 24-ft wide, which is the width of two typical traffic lanes.

Figure 1.1. TowPlow [1]

While the TowPlow may increase the efficiency and performance of the snow removal operation, the stability of the system under the harsh winter conditions may be compromised by implementation of the steerable trailer, and stability of the system must be ensured in terms of the lateral and yaw dynamics, load transfer, hill climbing, and low friction road conditions. This dissertation examines the stability of the TowPlow through both kinematic analysis and detailed dynamic modeling considering snow resistance, load transfer and gradability. The addition of control to the TowPlow to enhance its operational performance and stability, and broaden its applicability in the challenging winter operational conditions is also studied.

1.2 Literature survey

For the study of dynamic modeling and control of the TowPlow, related literature is reviewed in the following categories: kinematics, dynamics, snow resistance, and stability control. To constrain the scope of the review, it is confined to work related to articulated vehicles since the TowPlow is a unique type of this vehicle.

1.2.1

Kinematics of the articulated vehicle Kin …… 此处隐藏：6362字，全部文档内容请下载后查看。喜欢就下载吧 ……