Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Vehicle subsystem or accessory control
Reexamination Certificate
1999-06-01
2003-11-04
Cuchlinski, Jr., William A. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Vehicle subsystem or accessory control
C701S029000, C701S033000, C701S035000, C701S036000, C717S168000
Reexamination Certificate
active
06643572
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a vehicle controller capable of changing control software to a control algorithm newly developed to improve the performance early and by a relatively inexpensive apparatus in a market after selling a vehicle.
BACKGROUND ART
An electric-power-steering controller is described below as one of the conventional vehicle controllers.
FIG. 3
is a circuit diagram of the conventional power-steering controller disclosed in Japanese Patent Application No. 5-64268 in which a part of the controller is shown by a block diagram. In
FIG. 3
, a motor
40
for outputting an auxiliary torque to a vehicle steering wheel (not illustrated) is driven by a motor current IM supplied from a battery
41
. The ripple component of the motor current IM is absorbed by a capacitor
42
having a large capacity (1,000 &mgr;F to 3,600 &mgr;F) and detected by a shunt resistor
43
. Moreover, directions and values of the motor current IM are switched in accordance with the operation of a bridge circuit
44
having a plurality of semiconductor switching devices (e.g. FETs) Q
1
to Q
4
in accordance with the magnitude and direction of the auxiliary torque.
One end of the capacitor
42
is connected to the ground by a conductive wire L
1
. The semiconductor switching devices Q
1
to Q
4
are bridge-connected by wiring patterns P
1
and P
2
to constitute a bridge circuit
44
. Moreover, the wiring patterns P
1
and P
2
connect the bridge circuit
44
to the shunt resistor
43
. The output terminal of the bridge circuit
44
is constituted with a wiring pattern P
3
.
The motor
40
and battery
41
are connected to the bridge circuit
44
through the wiring pattern P
3
by a connector
45
having a plurality of lead terminals. The motor
40
and battery
41
are connected to the connector
45
by an external wiring L
2
. The motor current IM is supplied or cut off by a normally-open relay
46
according to necessity. The relay
46
, capacitor
42
, and shunt resistor
43
are connected each other by a wiring pattern P
4
. The connector
45
is connected to the ground by a wiring pattern P
5
. The wiring pattern P
3
serving as the output terminal of the bridge circuit
44
is connected to the connector
45
.
The motor
40
is driven by a driving circuit
47
through the bridge circuit
44
. Moreover, the driving circuit
47
drives the relay
46
. The driving circuit
47
is connected to the exciting coil of the relay
46
by a conductive wire L
3
. Moreover, the driving circuit
47
is connected to the bridge circuit
44
by a conductive wire L
4
. The motor current IM is detected by a motor current detection means
48
in accordance with the voltage appearing at the both ends of the shunt resistor
43
. The driving circuit
47
and motor current detection means
48
constitute the peripheral circuit element of a microcomputer
55
to be mentioned later.
The steering torque T of a steering wheel is detected by a torque sensor
50
and the speed V of a vehicle is detected by a speed sensor
51
. The microcomputer
55
(ECU) computes an auxiliary torque in accordance with the steering torque T and vehicle speed V, generates a driving signal corresponding to the auxiliary torque by returning the motor current IM, and outputs a rotational direction command D
0
and a current controlled variable I
0
for controlling the bridge circuit
44
to the driving circuit
47
as driving signals.
The microcomputer
55
is provided with motor current decision means
56
for generating the rotational direction command D
0
for the motor
40
and a motor current command Im corresponding to an auxiliary torque, subtraction means
57
for computing a current deviation &Dgr;I between the motor current command Im and the motor current IM, and PID operation means
58
for computing correction values of P (proportion) term, I (integration) term, and D (differentiation) term in accordance with the current deviation &Dgr;I and generating the current controlled variable I
0
corresponding to a PWM duty ratio.
Moreover, though not illustrated, the microcomputer
55
includes a publicly-known self-diagnostic function in addition to an AD converter and a PWM timer circuit, always self-diagnoses whether a system normally operates, and cuts off the motor current IM by releasing the relay
46
through the driving circuit
47
when a trouble occurs. The microcomputer
55
is connected to the driving circuit
47
through a conductive wire L
5
.
Then, operations of a conventional electric-power-steering controller are described below by referring to FIG.
3
. The microcomputer
55
captures the steering torque T and vehicle speed V from the torque sensor
50
and speed sensor
51
, feedback-inputs the motor current IM from the shunt resistor
43
, and generates the rotational direction command D
0
of a power steering and the current controlled variable I
0
corresponding to an auxiliary torque to output them to the driving circuit
47
through the conductive wire L
5
.
The driving circuit
47
closes the normally-open relay
46
in accordance with a command through the conductive wire L
3
under a normally driving state but it generates a PWM driving signal when the rotational direction command D
0
and current controlled variable I
0
are input and applies the signal to the semiconductor switching devices Q
1
to Q
4
of the bridge circuit
44
through the conductive wire L
4
.
According to the above circuit structure, the motor current IM is supplied from the battery
41
to the motor
40
through the external wiring L
2
, connector
45
, relay
46
, wiring pattern P
4
, shunt resistor
43
, wiring pattern P
1
, bridge circuit
44
, wiring pattern P
3
, connector
45
, and external wiring L
2
. The motor
40
is driven by the motor current IM to output a required mount of auxiliary torque in a required direction.
In this case, the motor current IM is detected through the shunt resistor
43
and motor current detection means
48
and returned to the subtraction means
57
in the microcomputer
55
and thereby, controlled so as to coincide with the motor current command Im. Moreover, though the motor current IM includes ripple components because of the switching operation of the bridge circuit
44
under PWM driving, it is smoothed and controlled by the large-capacity capacitor
42
.
A vehicle controller including this type of electric-power-steering controller conventionally uses a microcomputer having a built-in mask ROM storing control software such as control data and control programs.
However, because it is necessary to secure a predetermined mask ROM fabrication period under short-time system development, it is not temporally permitted to re-fabricate a mask ROM due to re-modification of software specification and it is necessary to early fix the software specification. Therefore, this causes the loads of development engineers to increase.
Moreover, also when changing control software for a newly-developed control algorithm in order to improve the performance in a market, it is necessary to secure a predetermined mask ROM fabrication period. However, it is impossible to re-fabricate a mask ROM because of changing the control software for the newly-developed control algorithm and to early change the control software in accordance with the newly-developed control algorithm. Furthermore, to reload the control software in a market, it is necessary to prepare an inexpensive auxiliary storage.
General control software is constituted with the part of discrete corresponding data between an input/output unit connected to a controller and the controller, the part of intrinsic data (e.g. torque-sensor neutral point learning data after final combination of the torque sensor
50
serving as an input/output unit with the controller of a vehicle or trouble history data in the controller mounted on a vehicle in a market after selling the vehicle), and the part of control algorithm.
Thus, the stored intrinsic data content of the intrinsic data storage block (region) in the control software of a storage to be
Kishimoto Yuji
Kohge Shinichi
Broadhead Brian J
Cuchlinski Jr. William A.
Mitsubushi Denki Kabushiki Kaisha
LandOfFree
Controller for automobile does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Controller for automobile, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Controller for automobile will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3185086