The new CROWN crown was listed in December 2009, compared to its previous model, the new crown not only made a change in the shape and interior design, but also to improve the performance of the vehicle with a large number of advanced technologies . In order to improve vehicle handling stability and comfort, air suspension uses a new crown (4.3 L model only), the AVS adaptive variable suspension system, a variable gear ratio steering system VGRS (4.3 L model only) and other advanced configuration. In improving safety, the new Crown adopts Vehicle Dynamics Integrated Management VDIM, pre-crash safety system PCS, adaptive radar cruise control system DRCC, intelligent parking assist system IPA (top model only) and G-BOOK intelligent Fujia, etc. advanced configuration. In order to facilitate the readers understanding of the car, in this case, the new crown will be some of the technical highlights of this paper are introduced.
First, the engine system
New Crown all models into 2.5 L, 3.0 L and 4.3 L 3 th emission levels, respectively, mounted 5GR-FE (2.5 L), 3GR-FE ( 3.0 L) and 3UZ-FE (4.3 L) 3 types of engines.
FIG 1
structure and control system 3GR-FE 5GR-FE engine and is substantially the same, both of which are V-type 6-cylinder 24-valve dual overhead camshaft structure, 3UZ-FE engine is a V-type 8-cylinder 32-valve dual overhead cam configuration (FIG. 1). All three types of engines are used the ACIS (variable inlet control system) and ETCS-i (Intelligent Electronic Throttle Control System) technology, and wherein 3GR-FE 5GR-FE 2 under engine intake / exhaust camshafts are used VVT-i (intelligent control system continuously variable valve timing) technology, also known as Dual VVT-i, 3UZ-FE engine camshaft using only intake VVT-i technology.
Further, 3GR-FE, and this 2 5GR-FE engine also has the following characteristics.
① using cartridge type oil filter.
② magnetoresistive type semiconductor (the MRE) type sensors VVT.
③ 3 with Valve timing chain.
④ with long threaded spark plug.
⑤ jacket using water separator to reduce friction losses.
⑥ hydraulic lash adjuster.
⑦ ACIS rotary solenoid type control valves.
⑧ camshaft holder to simplify the structure of the cylinder head.
Second, the chassis system
(a) Automatic Transmission
New Crown 3UZ-FE engine equipped A761E automatic transmission, 3GR-FE and 5GR-FE engine equipped A960E automatic transmission this section of the automatic transmission 2 are both 6-speed automatic transmission, includes a multi-mode control (ECO, SPORT and SNOW) functions, and uses a new method for adjusting the ATF bits, i.e., the oil level is provided for adjusting the overflow plug (no dipstick and filler pipe). In addition, this section of the automatic transmission 2 is also provided for checking the ATF temperature ATF temperature warning light, and eliminates the need for periodic inspection of the oil level ATF (just check for leaks). Here some of the features of this section of the automatic transmission 2 on the structure and control described specifically.
The planetary gear mechanism 1.
FIG. 2
Three sets of the planetary gear mechanism comprises planetary mechanism 4 as well as clutches, brakes, and composition of the one-way clutch. (FIG. 2)
2. Body
Figure 3
The upper and lower valve body and the solenoid valve 9 Composition ( FIG. 3), including five shift solenoid valves (S1 ~ S4 and SR), 4 linear solenoid valves (SL1, SL2, SLT and SLU), wherein the line pressure control valve SLT is, a lock-up solenoid valve SLU , as functions of the respective solenoid valves (table 1).
Table 1
3. idling control
idling control means when the vehicle is stoppedWhen the engine load is reduced by cutting off power transmission to improve fuel economy. D range selection lever disposed, when the vehicle is stopped, the transmission clutch-release C1, C4 and the brake B2, in order to reduce the load. Idling control is not operating in mode S block, but if the idling stop control process proceeds to S mode, this control will continue to operate.
4. deceleration downshift control
Figure 4
As can be seen (FIG. 4), the control by the deceleration downshift , 6 the vehicle speed to 5-speed, 5-speed to 4-speed process is completed before the fuel cut recovery, thus extending the time to reach the fuel cut recovery rotational speed, fuel cut time is also extended, so as to improve vehicle fuel the purpose of the economy.
(ii) brake system
New Crown all models are standard brake system of the ABS with EBD, BA (auxiliary brake), TRC (traction control), VSC ( vehicle stability control) and HAC (hill-start assist) system. In carrying 3GR-FE 3UZ-FE engine and the high-profile models, also using the VDIM (Vehicle Dynamics Integrated Management) system.
1. VDIM (Vehicle Dynamics Integrated Management) system concept
(1) VDIM control management
conventional brake control systems, ABS, TRC and VSC are individually controlled, while the VDIM control theory is an integrated ABS, TRC and VSC control system. The systems work in a coordinated under the management of VDIM, smooth vehicle control.
The following paper vehicle brake slip phenomenon occurs, the brake system and the traditional systems A comparison VDIM.
by a conventional brake control system to the received yaw rate and vehicle deceleration sensor, a vehicle speed sensor and a steering angle sensor determines whether the vehicle is skidding, when it is confirmed imminent skidding, start VSA system to stabilize the vehicle running. When the vehicle emergency braking, ABS braking control system activates the system, and to prevent locking of wheel skidding; if a skid is started VSC system stability. VDIM same system using the above-mentioned sensor signals as the basis for determining the vehicle running state, when detecting imminent skidding, VDIM control ABS, TRC and VSC coordinated work, unstable vehicle driving factor Save small to a minimum. As can be seen (FIG. 5), under control of the VDIM system, the vehicle traveling more stable than the conventional brake control system.
FIG. 5
(2) VDIM control theory
The control principle of VDIM (FIG. 6).
Figure 6
2. The brake assist function
The vehicle anti-skid control unit, the load-sensing brake pedal and the brake switch the master cylinder pressure sensor signal, determining the driver’s intention when the driver needs to confirm the emergency braking, the brake pressure is increased brake actuator.
3. The steering cooperative control function
When the anti-skid control unit drives the VSC system operation, the system through the variable gear ratio steering system and an electronic steering system EPS VGRS coordination, improved stability of the vehicle (Figure 7).
Figure 7
Third, the vehicle electrical system
(a) the MPX multiplex transmission system (in-vehicle network control system) [123 ]
the new crown MPX multiplex transmission system using four kinds of communication protocols, comprising: CAN, LIN, AVC-LAN, and MOST. CAN communication for the engine, chassis and body of the electrical system; the LIN body for internal communication system; AVC-LAN is only used for communication between the audio-visual (AV) system elements; the MOST (Media Oriented Systems Transport bus) for AV ( AV) communication between system elements. There are two types CAN wherein: HS-CAN (high speed) and MS-CAN (medium speed). The main body includes a gateway function of the control unit and a power management control unit converts signals between the CAN and LIN.
(b) Intelligent parking assist system IPA
intelligent parking assist system by looking at the rear view and assist the driver in parking guide line, and can automatically control the rotation of the steering wheel reaches the target parking position.
Figure 8
1. The intelligent parking assist system (Figure 8)
2. The intelligent parking assist system works
intelligent parking assist system works as (FIG. 9), the ambient temperature sensor system for correcting the signal from the bounce wave sensor detection.
Figure 9
(c) the pre-crash safety system
New Crown above 3.0 L model is equipped with a pre-crash safety system, when the collision is about to occur, pre-crash safety system will operate, respectively, related to the shock absorbing components to help reduce the damage caused by the collision. Before the collision, the vehicle system will proceed as follows: belt tightening, issued collision warning message, and to prepare a braking assist control for the pre-crash braking.
1. The pre-crash safety system and working principle
works as pre-crash safety system (FIG. 10).
10
(1) a front collision determination
support with control means through the front millimeter wave radar sensor detects a vehicle vehicle or obstacle, and according to the distance by the vehicle speed, road conditions and the distance to the obstacle, it is determined whether the collision is inevitable.
(2) emergency brake determining
Once a vehicle skid control unit emergency braking operation is performed seatbelt pretensioner. Determination of sudden braking is made by a signal and the brake hydraulic pressure of the brake master cylinder pressure sensor.
(3) determination of vehicle control
When there is a big possibility of a runaway vehicle, a seat belt pretensioner will also be activated. The control unit through the vehicle yaw rate sensor and a steering angle sensorThe information to determine whether the vehicle will be out of control.
2. The millimeter-wave radar sensor (FIG. 11)
11
can be obtained by the millimeter wave radar sensor detects reflected radar waves distance, relative speed and direction of the target, the sensor loop is a transmitter antenna 9 and receiving antenna. After replacing or dismantling of the sensor, the need for axial adjustment of the radar beam.
the step of adjusting the millimeter wave radar sensor is as follows.
① vertical direction using a level check and adjust the radar sensor.
② SST examination using intelligent detector position.
③ horizontal direction intelligent detector inspection and adjustment of the radar sensor.
④ metal (e.g. aluminum) to reset the learning value radar sensors (intelligent detector can be used to automatically reset the learning value).
⑤ utilization level check and adjust the vertical direction of the radar sensor again.
(Liu Tao Wang Quanlei)