MATLAB REAL-TIME WORKSHOP EMBEDDED CODER - S Manuale Utente Scaricare il pdf (Pagina 9)

1 Introduction

1.1 Background

Haldex Traction AB is part of the Haldex Group, which consists of four product

divisions: Haldex Brake Systems, Haldex Traction Systems, Haldex Hydraulic

Systems and Haldex Garphyttan Wire. Haldex Traction AB is responsible for the

manufacture and worldwide marketing of the advanced and flexible All-Wheel-

Drive-system, AWD-system.

Haldex Traction designs and develops a coupling called Haldex Limited Slip

Coupling, HLSC, which is a complete AWD-system. The coupling consists of two

main parts: torque transfer part and control system. The latter contains a

microprocessor with the needed software. The control system part is responsible

for controlling the coupling function with the desired properties, depending on

several factors e.g. the driving situation. The idea behind the coupling is that when

the front and rear shafts of the vehicle start to rotate with different speeds, e.g.,

due to slip, a hydraulic piston pump will start and generate an oil flow through an

open throttle valve. When the throttle valve is partially closed an oil pressure will

start to build up in the clutch piston. The clutch piston will then force discs in the

multi-plate clutch together leading to a torque capacity from the front to the rear

shaft, see Figure 1. The torque transferred in the coupling is thus a function of the

pressure. The idea here is to control the hydraulic pressure in the clutch in order to

be able to control the torque transfer. Today there are four generations of Haldex

Limited Slip Coupling and a fifth generation is under the development phase. The

tested HLSC in this work belongs to the second generation.

Figure 1: Schematic sketch of Haldex Limited Slip Coupling [1]

Today Matlab/Simulink is widely used to develop and test control models. At

Haldex, rapid prototyping is used, as well, to test control algorithms designed in

Simulink. A tool from dSPACE, called MicroAutoBox, is used for this purpose.

MicroAutoBox makes it possible to test the model on the target processor directly.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 ... 75 76

Nessun commento

MATLAB REAL-TIME WORKSHOP EMBEDDED CODER - S Manuale Utente Pagina 9