[0001] The present invention relates to a control module, more particularly, but not exclusively,
to a latch control module for a latch in an automotive vehicle.
[0002] It is known to provide a latch in the door of an automotive vehicle, for releasably
retaining the door in a closed position. Such latches can be used to lock the door
in the closed position when the car is unattended, or even if the vehicle is occupied,
so as to prevent unauthorised access to the vehicle.
[0003] Typically, such latches include a drive arrangement for moving the latch between
an unlocked condition and one or more locked conditions. The drive arrangement will
usually incorporate at least one motor for driving a component in the latch, to cause
the door to become locked or unlocked.
[0004] In conventional arrangements, the or each motor operates in response to signals from
an electronic control unit (ECU) in the vehicle, wherein each motor is operatively
coupled to the ECU via a wiring harness within the door.
[0005] If a motor is mounted in a latch with its terminals in an incorrect orientation for
the polarity of the power supply within the wiring harness, the motor will not rotate
in the desired direction, in use. In particular, the rotation of the motor may cause
a component in the latch to move to an open position instead of a closed position
or vice versa, thereby compromising the operative capacity of the latch.
[0006] Therefore, during current vehicle assembly operations, it is necessary to manually
check the operative orientation of each motor in a door latch, thereby limiting the
productivity of the assembly process.
[0007] It is an object of the invention to provide means which addresses the problem referred
to above.
[0008] According to the invention there is provided a method of testing a door latch mechanism,
comprising the steps of :
- i) mounting a motor in a door latch, wherein said motor has a movable output portion;
- ii) providing a power supply for driving the motor, in order to move said output portion
of the motor;
- iii) providing one or more sensors for generating a signal indicative of movement
of said output portion in a desired direction;
- iv) providing a controller in communication with said sensor(s) and said power supply;
and
- v) initiating power to the motor to move said output portion;
wherein the controller is configured to communicate with said sensor(s) to detect
said signal indicative of movement of the output portion of the motor in the desired
direction during or after the supply of power to the motor, and to generate a first
negative indicator if the controller fails to detect a signal from the sensor(s).
[0009] The controller may be configured to determine whether the motor has received an input
of power during the initiation of power to the motor, and to generate an alarm if
no input is determined.
[0010] In the preferred embodiment, the controller is configured to reverse the polarity
of the power supply to the motor in response to said first negative indicator.
[0011] The controller is preferably configured to generate a first positive indicator if
said signal indicative of movement of the output portion of the motor in the desired
direction is detected from the sensor(s).
[0012] There is also provided an apparatus for carrying out the above method. There is also
provided a computer program for controlling the controller of said method and/or said
apparatus.
[0013] According to a further aspect of the invention, there is provided a control module
comprising a controller and a sensor in communication with the controller; the controller
being configured for communication with a power supply for a motor having a motor
output portion which is movable upon activation from the power supply, and the sensor
being configured to generate a signal indicative of movement of said motor output
portion in a desired manner, wherein the controller is configured to communicate with
the sensor to detect said signal during or after the supply of power to the motor,
and to generate a negative indicator if the controller fails to detect said signal
from the sensor.
[0014] Preferably, the controller is configured to reverse the polarity of the power supply
to the motor in response to said negative indicator.
[0015] Other aspects and features of the invention will be readily apparent from the dependent
claims and the following description, which is provided, by way of example only, with
reference to the accompanying drawings, in which:
Figure 1 is a schematic view of a motor arrangement in accordance with a preferred
embodiment of the invention;
Figure 2 is a schematic block diagram of a latch assembly incorporating the motor
arrangement of Fig. 1; and
Figure 3 is a flow diagram showing the typical operation of a control module for the
door latch assembly of Figure 2.
[0016] Referring to Figure 1, a motor arrangement for a vehicle door latch is indicated
generally at 10. The arrangement includes an electric motor 12 having an output shaft
14, which is intended to be rotated, in use, for driving a component within the door
latch, for example to lock or unlock the door latch.
[0017] The motor 12 has first and second terminals 16, 18, for electrical connection with
a power supply, for rotating the output shaft 14.
[0018] The motor 12 is operatively coupled to a vehicle door wiring harness, an end portion
of which is indicated generally at 20. Wiring harness 20 includes first and second
wires 22, 24 which are coupled to the respective first and second terminals 14, 16
via an electrical connector 26.
[0019] In this embodiment, the motor arrangement 10 is mounted in a left hand side door
in a vehicle, which requires the output shaft 14 of the motor 12 to rotate in an anticlockwise
direction, in order to cause a component within the latch to move from a first locked
position to an unlocked position, in order to unlatch the door.
[0020] Clearly, if the terminals 16, 18 of the motor 12 are incorrectly orientated with
respect to the polarity of the power supply from the wires 22, 24, the output shaft
14 of the motor 12 will rotate in the clockwise direction, which will prevent the
door from being unlatched during activation of the motor 12.
[0021] Figure 2 shows a schematic block diagram of a door latch assembly 30 into which the
motor arrangement 10 from Figure 1 has been fitted. The latch 30 includes a first
component 32, which is intended to pivot from a first position to a second position,
in response to rotation of the output shaft of the motor arrangement 10, so as to
lock the latch 30. The latch 30 also includes a sensor 34 which is arranged to detect
whether the component 32 has moved to its second position.
[0022] The motor arrangement 10 and sensor 34 are both coupled to an ECU 36 in the vehicle,
via a wire harness indicated at 38.
[0023] During a typical assembly process for a vehicle, the motor 12 is mounted in the door
latch 30, before being electrically connected to the wire harness 38. With the door
latch 30 mounted in a respective door, the door is closed in such a manner as to bring
the latch 30 into a locked condition. In the locked condition, the first component
32 is arranged in a first position, such that, under rotation of the output shaft
14 of the motor 12 in the correct rotary direction, the component 32 will be caused
to move to a second position, whereby the latch 30 assumes an unlocked condition.
[0024] It should be noted that the ECU 36 in Figure 2 includes a control module 40, operation
of which is controlled by a computer program. A typical operation of the control module
40 in combination with the motor arrangement 10 will now be described with reference
to Figures 2 and 3.
[0025] With the latch 30 in a known locked condition, the control module 40 is programmed
to enter a 'first check' mode. In this mode, the module 40 communicates with the ECU
36, so as to initiate a supply of power to the motor 12, via the wire harness 38,
in order to rotate the output shaft 14 of the motor 12 in a first direction.
[0026] The control module 40 is programmed to recognise that the component 32 in the door
latch 30 should be moved from the first position to the second position, in response
to this first actuation of the motor 12. In particular, the control module 40 is programmed
to anticipate that the sensor 34 will detect the movement of the latch component 32
from the first position to the second position, in response to this actuation of the
motor 12.
[0027] After a set time period, the control module 40 is programmed to enter a 'second check'
mode, wherein the module 40 checks whether the ECU 36 has received a signal from the
sensor 34 indicative of the desired movement of the latch component 32, i.e. to detect
whether the latch 30 has assumed an unlocked condition.
[0028] If the control module 40 detects that no such signal has been received within the
predetermined time period, the control module 40 is programmed to enter a 'fault finding'
mode, to determine whether the motor 12 has been incorrectly orientated in the door
latch 30, or whether there has been a more significant fault in the assembly process.
[0029] As a first step in the 'fault finding' mode, the control module causes the ECU 36
to reverse the polarity of the power supply to the motor 12. For example, if the wire
harness 38 was previously configured as a positive-negative power supply across the
respective wires 22, 24, the polarity is reversed so that the harness 38 is effectively
supplying power to the motor 12 in a negative-positive sense.
[0030] After the polarity of the power supply has been reversed, the control module 40 re-enters
the 'first check' mode, in order to initiate power to the motor 12, to move the latch
component 32. This is then followed by a further 'second check' mode, to await a signal
from the sensor 34.
[0031] If the control module 40 detects that a signal is received by the ECU 36 in the further
second check mode, then the control module 40 ends its programme and the vehicle is
allowed to move on to the next stage in the assembly process.
[0032] If, on the other hand, the control module 40 identifies that sensor 34 has not detected
movement of the latch component 32 during the further second check mode, the control
module 40 generates an alarm signal, to indicate that closer inspection is required,
for example manual inspection.
[0033] It should be understood that the control module 40 and ECU 36 may be connected to
any number of motors in any given latch, and may be connected to a plurality of given
latches on a vehicle. The controller 40 can be configured for testing each motor,
simultaneously, or sequentially, as required. A separate sensor can be provided for
each motor, for detecting the operative movement thereof, for example to monitor motors
used for general lock/unlock operations, as well as superlock, power release, power
cinch and child safety operations within one or more latches.
[0034] It will be appreciated that the invention is of particular benefit in reducing the
number of manual checks that would otherwise be required when initially fitting a
latch to a vehicle door during the first assembly of the vehicle.
[0035] The control module may include a memory, which is programmed to store the operative
orientation of each motor in a given latch, as determined by the above described method.
This is of advantage if the ECU is reset after the initial assembly of the vehicle.
In particular, by remembering the operative orientation of the motor, the control
module can ensure that the polarity of the power supply to the motor is correct, upon
re-setting of the ECU.
[0036] The module is also capable of detecting whether there has been a fundamental problem
with the motor. For example, the control module can be configured to detect whether
the motor is initiated to rotate at all during the first check mode, by monitoring
the current flow during the initiation of power to the motor.
[0037] The module is advantageous, not only in that it can be used to detect whether a motor
in a vehicle door latch is operating in a desired direction, it can also be instrumental
in detecting whether there has been another failure in the vehicle door latch, such
as a failure or anomaly within the motor or the remainder of the latch, for example
the failure of an associated sensor or movable latch component.
1. A method of testing a door latch mechanism, comprising the steps of :
i) mounting a motor in a door latch, wherein said motor has a movable output portion;
ii) providing a power supply for driving the motor, in order to move said output portion
of the motor;
iii) providing one or more sensors for generating a signal indicative of movement
of said output portion in a desired direction;
iv) providing a controller in communication with said sensor(s) and said power supply;
v) initiating power to the motor to move said output portion; and
vi) the controller being configured to communicate with said sensor(s) to detect said
signal indicative of movement of the output portion of the motor in the desired direction
during or after the supply of power to the motor, and to generate a first negative
indicator if the controller fails to detect a signal from the sensor(s),
wherein the controller is configured to reverse the polarity of the power supply to
the motor in response to said first negative indicator.
2. A method according to claim 1, wherein, after the polarity of the power supply has
been reversed, the controller is configured to re-communicate with said sensor(s)
to detect a signal indicative of movement of the output portion of the motor in the
desired direction, and to generate a second negative indicator if the controller again
fails to detect a signal from the sensor(s).
3. A method according to claim 2, wherein an alarm is generated in response to said second
negative indicator.
4. A method according to any of claims 1 to 3, wherein the controller is configured to
generate a first positive indicator if said signal indicative of movement of the output
portion of the motor in the desired direction is detected from the sensor(s).
5. A method according to claim 4, wherein the controller is configured to store the polarity
of the power supply to the motor, upon receiving said signal from the sensor(s).
6. A method according to any preceding claim, wherein the controller is configured to
determine whether the motor has received an input of power during the initiation of
power to the motor, and to generate an alarm if no input is determined.
7. A method according to any preceding claim, comprising the steps of providing a plurality
of said motors in the door latch, each motor having an output portion and a power
supply for driving said output portion, wherein one or more sensors is provided in
communication with each motor for generating a signal indicative of movement of the
output portion of each motor in a desired direction, and wherein the controller is
arranged in operative communication with each sensor for testing each motor.
8. A method according to claim 7, wherein the controller is configured to test the motors
sequentially, one after another.
9. A method according to claim 7, wherein the controller is configured to test at least
two motors concurrently.
10. A method according to any preceding claim, comprising the steps of providing a plurality
of said door latches, each including at least one motor having an associated power
supply for driving an output portion of the motor and an associated sensor for generating
a signal indicative of movement of the output portion of the or each motor in a desired
direction, and arranging the controller in operative communication with each sensor
for testing each motor.
11. A control module comprising:
a controller, and
a sensor in communication with the controller;
the controller being configured for communication with a power supply for a motor
having a motor output portion which is movable upon activation from the power supply,
and the sensor being configured to generate a signal indicative of movement of said
motor output portion in a desired manner,
wherein the controller is configured to communicate with the sensor to detect said
signal during or after the supply of power to the motor, and to generate a negative
indicator if the controller fails to detect said signal from the sensor.
12. A control module according to claim 11, wherein the controller is configured to reverse
the polarity of the power supply to the motor in response to said negative indicator.
13. A control module according to claim 11 or 12, wherein the controller is configured
to determine whether the motor has received an input of power during the supply of
power to the motor, and to generate an alarm if no input is determined.