Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Indication or control of braking – acceleration – or deceleration
Reexamination Certificate
1999-08-10
2001-01-23
Cuchlinski, Jr., William A. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Indication or control of braking, acceleration, or deceleration
C701S093000, C701S095000, C340S436000, C340S901000, C340S903000, C180S167000, C123S352000
Reexamination Certificate
active
06178372
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a motor vehicle drive system controller, particularly to a motor vehicle drive system controller of the type adapted to controlling the operation of the automatic drive system to optimize the running speed of a motor vehicle by controlling the power output of the engine or the electric motor and controlling the gear selection of the automatic transmission according to a set of given parameters.
2. Description of the Related Art
Demand for automatic motor vehicle drive systems that can effectively reduce the physical and psychological load on the part of the driver by automatically controlling some of the operations of driving the motor vehicle for the driver has increased. Currently available motor vehicle drive system controllers are mostly designed to control the running speed of the motor vehicle by controlling the opening of the engine throttle valve. On the other hand, motor vehicle drive system controllers designed to control the running speed of the motor vehicle by controlling not only the opening of the engine throttle valve, but also the gear-shifting operation of the automatic transmission have been proposed and commercialized with some success.
An automatic drive controller is typically either of a constant speed type or of a follower type. A constant speed type automatic drive controller controls the motor vehicle drive system including the engine in such a way that the motor vehicle is constantly driven to run at an intended speed. On the other hand, with a follower type automatic drive controller, the motor vehicle is made to follow an arbitrarily selected preceding vehicle, constantly maintaining a given distance from that vehicle. The arbitrarily selected lead vehicle is also called a target vehicle. Automatic drive controllers that can operate both in a constant speed mode and in a follower mode have also been proposed. With such a controller, the motor vehicle is driven to move at a constant speed until a target vehicle is caught in sight, when the automatic vehicle drive operation is switched to the follower mode.
A follower type controller determines the distance separating the leading vehicle and itself by means of a radar and then calculates a desired inter-vehicular distance for the follower on the basis of the speed of the leading vehicle detected by a speed sensor. The motor vehicle drive system is then so controlled as to make the actual inter-vehicular distance agree with the desired value. The motor vehicle may have to adapt itself to sudden deceleration of the leading vehicle and a motor vehicle suddenly intervening between the leading vehicle and the following vehicle. The automatic transmission then shifts gears down and the follower vehicle is decelerated by the braking effect of the engine.
Japanese Patent Laid-open Publication No. Hei 6-11200 discloses an automatic drive controller that determines the inter-vehicular distance between the leading vehicle and the following vehicle by means of a laser radar and, once a shortened distance is detected, causes the automatic transmission to downshift gears to decelerate the motor vehicle.
Japanese Patent Laid-Open Publication No. Hei 4-208647 teaches an automatic drive controller for controlling the automatic transmission so as to cause it to appropriately shift gears and drive the motor vehicle at a constant running speed. The controller shown in that publication causes the automatic transmission to shift gears down for accelerating the moving vehicle and up when the target speed is achieved. Japanese Patent Laid-Open Publication No. Hei 7-304349 also described an automatic drive controller for driving a motor vehicle at a constant running speed by controlling the operation of the automatic transmission.
In a related technological field, a control apparatus for regulating the running speed of a motor vehicle by locking up the torque convert apparatus is disclosed by the applicant of the present patent application in Japanese Patent Application No. Hei 8-147084. With this apparatus, a lock-up clutch arranged in parallel with the torque converter is engaged to produce a locked-up state or a locked-up slipping state whenever necessary in order to realize an enhanced level of deceleration.
A motor vehicle is driven by the motor vehicle drive system either in a drivable mode or in an undrivable mode as shown in
FIG. 1
of the accompanying drawings, which is a graph schematically illustrating the relationship between the engine torque T (axis of ordinate) and the running speed v (axis of abscissa) of the motor vehicle. In the drivable mode, the drive force of the motor vehicle engine exceeds the running resistance of the motor vehicle (hereinafter referred simply as “running resistance”) and the engine is positively driving the motor vehicle. On the other hand, in the undrivable mode the drive force of the engine falls below the running resistance and the motor vehicle may be decelerated by the braking effect of the engine.
The gear-shifting operation of the automatic transmission is controlled differently in the drivable mode and in the undrivable mode. This difference may be attributable to the structural requirements of the transmission, as will be described in greater detail hereinafter, or to the requirement of alleviating the impact at the time of shifting gears and improving the driver's comfort in the running motor vehicle. Thus, the automatic drive controller is required to determine if the motor vehicle is in a drivable mode or in an undrivable mode at the time of shifting gears in order to properly control the automatic transmission. This operation of finding out the driving mode on the part of the automatic drive controller is typically carried out on the basis of the throttle opening and the running speed of the motor vehicle detected by the speedometer as shown in FIG.
2
. In
FIG. 2
, the axis of abscissa and that of ordinate respectively represent the motor vehicle running speed v and the throttle opening &thgr;. The solid curve in
FIG. 2
indicates the reference running resistance or the reference resistive throttle opening of the engine, which is determined by converting the running resistance of
FIG. 1
into the throttle opening according to a predetermined relationship between the engine torque and the throttle opening. Then, the mode of operation of the engine is determined by comparing the detected throttle opening &thgr; and the reference resistive throttle opening for the detected running speed of the motor vehicle.
A typical situation where the operation of shifting gears is carried out by the automatic drive controller while determining if the motor vehicle running in a drivable mode or in an undrivable mode is when the running motor vehicle needs to be quickly decelerated while it is following a target vehicle. In such a situation, the gears must be shifted the instant when such deceleration is determined necessary. Thus, when deceleration is requested and it is detected that the motor vehicle is running in a drivable mode, the gear-shifting operation has to be controlled in a manner adapted to the drivable mode. When, on the other hand, deceleration is requested and the motor vehicle is found to be running in an undrivable mode, the gear-shifting operation has to be so controlled as to adapt itself to the undrivable mode. The throttle may have to be simultaneously closed, totally if necessary, for further deceleration.
Example situation in which the gear-shifting operation has to be conducted differently in drivable and undrivable modes
A situation where the gear-shifting operation has to be conducted differently in the drivable mode and in the undrivable mode will now be described by way of an example.
FIG. 3
is a schematic diagram of an automatic transmission described in Japanese Patent Laid-Open Publication No. Hei 6-341522 and
FIG. 4
is an operation chart of the frictional engaging devices of the automatic transmission for different gear positions. Referring to
FIG. 3
, the autom
Fukumura Kagenori
Nakamura Yasunari
Tabata Atsushi
Taniguchi Hiroji
Tomomatsu Hideo
Beaulieu Yonel
Cuchlinski Jr. William A.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Toyota Jidosha & Kabushiki Kaisha
LandOfFree
Motor vehicle drive system controller and automatic drive... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Motor vehicle drive system controller and automatic drive..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Motor vehicle drive system controller and automatic drive... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2546501