CLIAMS:1. A method for controlling one or more relays in a vehicle, said method comprising:
detecting an ignition OFF state of the vehicle by a control unit;
identifying reset operation of the control unit, said reset operation is identified by checking a predefined register configured in a memory unit of the control unit;
obtaining number of times reset operation is performed on the control unit from a reset counter configured in the memory unit; and
powering OFF one or more components for a predetermined amount of time when the number of times reset operation performed is greater than or equal to a pre-set value, thereby controlling the one or more relays in the vehicle.

2. The method as claimed in claim 1, wherein the reset counter is incremented by a predefined value upon identifying reset operation and the number of times reset operation is less than the pre-set value.

3. The method as claimed in claim 1, wherein the predetermined amount of time configurable in a range of 1 second to 5 seconds.

4. The method as claimed in claim 1, wherein the one or more components are one or more glow plugs and one or more fan.

5. The method as claimed in claim 1, wherein the comparison of obtained number of times reset operation with the pre-set value is performed by a comparator configured in the control unit.

6. The method as claimed in claim 1, wherein a predefined time period is set by a first timer configured in the control unit within which if the reset operation is not performed, the reset counter is set to zero.

7. The method as claimed in claim 1, wherein the predetermined amount of time to power OFF the one or more components is set by second timer configured in the control unit.

8. A system for controlling one or more relays in a vehicle, said system comprising:
a control unit configured to:
detect an ignition OFF state of the vehicle;
identify reset operation of the control unit, said reset operation is identified by checking a predefined register configured in a memory unit of the control unit;
obtain number of times reset operation performed on the control unit from a reset counter configured in the memory unit; and
power OFF one or more components for a predetermined amount of time when the number of times reset operation performed is greater than or equal to a pre-set value , thereby controlling the one or more relays in the vehicle.
9. The system as claimed in claim 8 further comprising a second timer to set the predetermined amount of time for powering OFF the one or more components.

10. The system as claimed in claim 8 further comprising a comparator to compare the obtained number of times reset operation with the pre-set value.

11. The system as claimed in claim 8, wherein the one or more components are one or more glow plugs, and one or more fans.
,TagSPECI:TECHNICAL FIELD
The present disclosure relates to controlling relays in a vehicle. More particularly, the present disclosure relates to a method of controlling one or more relays in the vehicle from chattering or welding during reset operations performed in case of low battery conditions.
BACKGROUND
Generally, diesel vehicles make use of one or more modules including, but not limiting to, glow plugs, fan controller, exhaust gas recirculation (EGR) controller which serves diesel engines. A glow plug is a heating device used to aid starting diesel engines. Heat generated by the glow plugs is directed into cylinders, and serves to warm the engine block immediately surrounding the cylinders. The fan controller is used to take out the heat from the engine block surrounding the cylinders. The EGR controller is used to recirculate the exhaust air to a turbo charger connected to the engine block. Each of the glow plugs, the fan controller and the EGR controller draws electrical charges from a battery which is run by a relay contact. The relay contact is an electrically operated switch to operate a switching mechanism. Additionally, each of the glow plugs, the fan controller and the EGR controller comprises controller circuit i.e. the glow plugs are commonly controlled by a glow plug timer or an Engine Control Unit (ECU). Similarly, the fan controller is controlled by fan controller circuit and EGR controller is controlled by an EGR controller circuit. The ECU or glow plug timer unit and fan control unit is powered by a battery and the radiator fan and glow plug outputs are driven by a relay contact whose coil ground is controlled by the ECU.
In automotive vehicles, the glow plugs extend into the cylinder of the engine, to provide preheating of the cylinder wall and air inside the cylinder being compressed when the engine is being started. The glow plugs are energized by drawing energy from the battery before starting of the engine. After starting, the glow plugs can continue to be energized, however with reduced power, depending on the temperature then pertaining in the interior of the cylinder, so that continued combustion in the respective cylinders can be sustained upon injection of fuel into the compressed air. Generally, huge amount of current/energy is drawn by the glow plugs from the battery, may be around 10A, by each glow plug. The battery is drained out when high current/energy is drawn by the glow plugs. If battery voltage drops below a certain value in low battery condition, the microcontroller/ ECU reset. During this reset operation, the relay contact is chattered due to continuous switching ON/OFF of coil ground. The chattering results in welding of the relay contact and can make permanent contact of battery with glow plug/fan output which results in transferring the current continuously even when the ignition is in OFF state. Therefore, chattering results in damage of the relay contact which in turn results to shut down the working of the vehicle.

Also, the fan controller circuit draws current from the battery through a relay.

Conventional methods provides matching of operating circuit of a diesel engine to a glow plug system including an interface and a control unit that includes a microprocessor (MP) which decodes data words received from an engine control unit (ECU). The data words are in the form of serially transmitted bits which define, by time duration of the bits. Logic "0" and logic "1" values provides data information and synchronizing information respectively. For example, the logic "0" bits may be 1/8 of a predetermined clock period (T), whereas the logic "1" bits may be 1/2 of the clock period (T). The microprocessor may be matched to engines of different types to carry out diagnostic routines and indicator functions under command of respective bits being transmitted. A glow plug current is provided in pulsed form, the duty cycle of which is controlled by four data bits (D0-D4) transmitted to the microprocessor (MP). However, the method does not mention about prevention of relay from chattering. The method only mentions about sending the ignition bits to the glow plug unit.

Another conventional method describes a glow plug controller for an engine, for example, a diesel engine which has a novel packaging, and means for facilitating rapid and inexpensive assembly. Plurality of connector pins are conductively coupled to the glow plug circuitry via portions of conductive foil on a surface of a circuit board. A unique short circuit cut-off is provided wherein a short circuit in the glow plug relay control disables application of power to the relay control circuit. The glow plug controller used for vehicle diesel engine contains two chambers one of which consists of a glow plug circuitry and the other consists of a temperature sensor connected through connector pins. The glow plug controller includes a fault detection circuit for detecting a short circuit to ground on the glow plug controller output which drives the external glow plug relay. However, the method does not mention about the integrated radiator fan circuitry and glow plug timer circuitry. The only mentions about the glow plug timer and maintaining the temperature of glow plugs. This method does not mention about reset detection to be used to prevent relay chattering and welding.

Hence, there is a need of a method to prevent chattering and welding of the relay contact in case of low battery condition. Hence, there exists a need for a method to control glow plug and fans.

SUMMARY
The shortcomings of the prior art are overcome and additional advantages are provided through the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
In one embodiment, the present disclosure relates to a method for controlling one or more relays in a vehicle. The method comprises detecting an ignition OFF state of the vehicle by a control unit. The one or more relays are in OFF condition when the vehicle is in the ignition OFF state. Then, reset operation of the control unit is identified during the ignition OFF state. The reset operation is identified by checking a predefined register configured in a memory unit of the control unit. The number of times the reset operation performed on the control unit is obtained from a reset counter configured in the memory unit. Then, one or more components are powered OFF for a predetermined amount of time when the number of times the reset operation performed is greater than or equal to a pre-set value, thereby controlling the one or more relays in the vehicle.

In one embodiment, the present disclosure relates to a system for controlling one or more relays in a vehicle. The system comprises a control unit which is configured to detect an ignition OFF state of the vehicle. The one or more relays are in OFF condition when the vehicle is in the ignition OFF state. Then, reset operation of the control unit is identified during the ignition OFF state. The reset operation is identified by checking a predefined register configured in a memory unit of the control unit. The number of times the reset operation performed on the control unit is obtained from a reset counter configured in the memory unit. One or more components are powered OFF for a predetermined amount of time when the number of times the reset operation performed is greater than or equal to a pre-set value, thereby controlling the one or more relays in the vehicle.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects and features described above, further aspects, and features will become apparent by reference to the drawings and the following detailed description.

OBJECTIVE OF THE INVENTION

The object of the present disclosure is to control one or more relays from chattering or welding caused by reset operations during low battery conditions. The other main objective is to differentiate a normal ignition on/off cycle from a warm reset condition which generally occurs when the battery is very low. Therefore, a method for controlling the one or more relays is disclosed by the present disclosure which obtains the number of times reset operation is performed on the control unit during the low battery conditions. Based on the obtained number of times the reset operation are performed, one or more components which are causing the battery to drain out are shut down or powered OFF in order to control the one or more relays from chattering or welding.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features and characteristic of the disclosure are set forth in the appended claims. The embodiments of the disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings.

Figure 1 illustrates a block diagram of an exemplary system for controlling one or more relays in a vehicle in accordance with an embodiment of the present disclosure;

Figure 2 illustrates a block diagram of exemplary system for controlling one or more relays in a vehicle integrated with one or more component in accordance with an embodiment of the present disclosure;

Figure 3 illustrates power supply circuit in which capacitor and transistor are used to hold power to control unit when the vehicle is in ignition OFF state in accordance with an embodiment of the present disclosure;

Figure 4 shows a memory unit in the control unit used which stores ignition ON/OFF state of the vehicle in accordance with an embodiment of the present disclosure; and

Figures 5 illustrates a flowchart of a method for controlling one or more relays in a vehicle in accordance with an embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific aspect disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
The present disclosure is related to a method for controlling one or more relays in a vehicle. More particularly, the one or more relays are controlled from chattering or welding which is caused due to reset operations during low battery condition. In the method, firstly an ignition OFF state of the vehicle is detected by a control unit. The ignition OFF state is because of two conditions. First condition is when the ignition is switched OFF manually, which is detected based on the voltage or power across one or more capacitors and/or transistors. The second condition to detect the ignition OFF state is that, when a power value of a battery is less than a predefined power value which occurs when one or more components drawing power from the battery through the one or more relays. Usually, during the ignition OFF state of the vehicle, the one or more relays are in OFF condition and reset operations are performed on the control unit through the one or more relays.
The reset operation is identified by checking a predefined register configured in a memory unit of the control unit. If the reset operation is performed within the predetermined time period set by a first timer configured in the control unit, a reset counter configured in the memory unit is incremented or varied. Otherwise, the reset counter is made zero. The number of times the reset operation is performed is obtained from the reset counter. If the number of times the reset operation performed is less than a pre-set value then the reset counter is incremented by a predefined value. In case, the number of times the reset operation performed is greater than or equal to a pre-set value, then one or more components are powered OFF for a predetermined amount of time for controlling the one or more relays in the vehicle. For example, let the number of times reset operation required be 6, which is a pre-set value, to power OFF the one or more components to control the one or more relays from chattering or welding. In case, if the number of times reset operation performed is 3 in one minute time, which is a predetermined time period. If the number of times a reset operation performed is 3, which is less than the pre-set value 6, then the one or more relays are considered to be in normal condition without any chattering and also the reset counter is incremented by one i.e. the reset counter becomes four in the predefined time period. On the elapse of the predefined time period, the reset counter is initialized to zero. If the number of times reset operation performed is 7 in one minute, which is a predetermined time period. The number of times a reset operation performed is 7 which are more than pre-set value 6, then the one or more relays are considered to be undergoing damage such as chattering and thereafter welding. Hence, the one or more components are powered OFF by the control unit. In the present disclosure, the glow plugs and fan controllers are configured with a control unit.
Figure 1 illustrates a general block diagram of a system for controlling one or more relays in a vehicle, in accordance with an embodiment of the present disclosure. The system comprises a control unit 101 for controlling one or more components through one or more relays. In an embodiment, the control unit 101 receives one or more inputs 100 which affect the one or more relays. The one or more inputs include, but does not limit to, throttle position (TPS), engine rotation per minute (rpm), crank, vehicle speed, Exhaust Gas Recirculation (EGR) feedback are connected to the control unit 101. A negative temperature coefficient (NTC) type coolant temperature sensor 100a is also connected to the control unit 101. Based on the one or more inputs 100 received by the control unit 101, EGR modulator 102, malfunction indicator lamp (MIL) 103, check engine lamp (CEL) 104, glow plug lamp 105, glow plug relay 106 and fan relay 107 control the one or more glow plugs 106a and the one or more fan 107a respectively.

Figure 2 illustrates a block diagram of a system 200 for controlling one or more relays (202a and 202b) in a vehicle, in accordance with an exemplary embodiment of the present disclosure. The system 200 comprises at least one battery 201, the one or more relays 202a and 202b collectively referred to as 202, and the control unit 101. In the vehicle, usually the one or more relays 202 are used to provide power supply or switching mechanism for one or more components including, but not limiting to, one or more glow plugs 207 and one or more fans 208. The one or more glow plugs 207 are used as a heating device used to aid starting vehicle engines. The heat generated by the one or more glow plugs 207 is directed into the cylinders (not shown in figure 2), and serves to warm the engine block (not shown in figure 2) immediately surrounding the cylinders. The one or more glow plugs 207 are energized by using a power from the battery 201 through one of the one or more relays 202. The one or more fan 208 are also called radiator fan are used to cool internal combustion engine of the vehicle. The one or more fans are powered by the battery 201 through one of the one or more relays 202, said one or more relays are controlled by the fans 208. The system prevents the one or more relays from chattering and thereafter welding due to low battery condition of the battery 201.

In an embodiment, the one or more relays 202, the one or more glow plugs 207 and the one or more fans 208 are controlled by the control unit 101 to prevent the one or more relays from chattering or welding which occurs when a power in the battery 201 is less than a predefined power value. The control unit 101 comprises a memory unit 203, a first timer 205a, a second timer 205b and a comparator 206. In an embodiment, the control unit 101 detects state of the vehicle such as an ignition ON/OFF state. Particularly, the control unit 101 detects an ignition OFF state of the vehicle. While the vehicle is in the ignition OFF state, the one or more relays 202 are in OFF condition i.e. no power is passed through the one or more relays 202.

The ignition OFF state of vehicle is detected by the control unit 101 in two ways. Firstly, when the vehicle is manually switched OFF which is, considered as a normal ignition OFF state of the vehicle. In an embodiment, at least one capacitor (not shown in figure 2) and at least one transistor (not shown in figure 2) is used to hold up the power to the control unit 101 for a predetermined time, for example, 300 milliseconds (ms), when the vehicle is switched OFF manually i.e. under normal ignition OFF state of the vehicle. From the power received from the capacitor, a power down routine method is performed by the control unit 101 and then the normal ignition OFF state of the vehicle is detected.

In an embodiment, the memory unit 203 comprises a register 204a and a reset counter 204b. The memory unit 203 includes, but not limited to, RAM, EPROM, EEPROM, or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store data. Combinations of the above should also be included within the scope of computer readable media. Executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions.

The control unit 101 updates the predefined register 204a configured in the memory unit 203 with a flag value as ‘1’ or ‘0’ based on the detection of the ignition ON/OFF state of the vehicle. For example, in an embodiment, the flag value in the predefined register 204a is ‘1’ when the vehicle is in the normal ignition OFF state and a ‘0’ indicate a reset had occurred. In an embodiment, the memory unit is a non-volatile memory unit and the control unit 101 is a microcontroller. The reset operation is performed when the power at the control unit 101 drops below a predefined power value. For example, the one or more glow plugs 207 draws high power from the battery 201. The one or more glow plugs output is turned on, the power across the battery 201 drops significantly due to the internal resistance of the battery 201. As a result, the power at the control unit 101 drops below the predefined power value when the glow plugs output is turned on. When the control unit 101 resets i.e. when the reset operation is performed, the power is again restored to a value which is above the predefined power value since the glow plugs are switched OFF. But, as soon as the glow plugs are turned on again, the above cycle repeats which leads to the relay chattering.

The reset operation performed by the control unit 101 is identified. The reset operation to be performed is identified by checking the predefined register 204a configured in the memory unit of the control unit 101. When the reset operation is performed the flag value in the register 204a is ‘0’.

Upon identifying the number of times reset operation is performed by the control unit 101, which is obtained from the reset counter 204b configured in the memory unit 203. The reset counter is incremented by a predefined value, for example, by 1, when the number of times the reset operations are performed. If a reset is not performed within the predetermined time period set by the first timer 205a, then the reset counter 204b is made zero. For example, the reset counter 204b is incremented by 1 each time the reset operation is performed within the predetermined time period of 30 seconds. On elapse of predetermined time period, the reset counter is initialized to zero. The one or more components including, but not limiting to, the one or more glow plugs 207 and the one or more fans 208 are powered OFF for a predetermined amount of time when the number of times reset operation performed is greater than or equal to a pre-set value. The comparison of the number of times reset operation with the pre-set value is performed by the comparator 206. For example, considering the pre-set value is 6 which is the number of times reset operation is required. If the number of times of reset operation is 3 in one minute (which is the predetermined time period set by the first timer 205a) then the one or more relays 202 are considered to be in normal condition without any chattering and also the reset counter 204b is incremented by one i.e. the reset counter 204b becomes four in the predefined time period. On the elapse of the predefined time period, the reset counter 204b is initialized to zero. Considering the number of times reset operation performed is 7 in one minute, which is a predetermined time period. The number of times a reset operation performed is 7 which are more than pre-set value 6, then the one or more relays 202 are considered to be undergoing damage such as chattering and thereafter welding. Hence, the one or more components i.e. the one or more glow plugs 207 and the one or more fans 208 are powered OFF for the predetermined amount of time set by the second timer 205b by the control unit 101. In an embodiment, the predetermined amount of time is configurable by the second timer 205b in the range of 1 second to 5 seconds, thereby controlling the one or more relays 202 in the vehicle.
Figure 3 illustrates power supply circuit in which one or more capacitors and/ or transistors are used to hold power to control unit 101 when the vehicle is powered OFF i.e. in ignition OFF state in accordance with an embodiment of the present disclosure. During normal ignition OFF state of the vehicle, the charge across the capacitor C254 holds and supplied power to the control unit 101 for a predefined time. The ignition input is taken from the connector pin X2.7 and applied to a signal conditioning circuit and given as an input to the control unit 101 to sense ignition OFF and during that time the capacitor C254 holds charge to the control unit 101 which senses this input switch from ON to OFF and executes the power down delay routine. When ignition is switched off, the charge across the capacitor holds power to the control unit 101 for a short time, for example, of about 300ms. During this time, information about the state of the vehicle is updated in the register 204a of the memory unit 203 in the control unit 101. On the other hand, if the reset operations of the control unit 101 are performed, then the capacitor C254 does not come into picture as ignition input is not switched OFF to ‘0’. When the ignition is switched off during normal functioning, the value of the ignition OFF flag is made ‘1’ and stored in the register 204a. This is done during the 300ms period during which the capacitor holds the power up.

Figure 4 shows a memory unit 203 in the control unit 101 for storing ignition ON/OFF state of the vehicle, in accordance with an embodiment of the present disclosure. As shown the figure 4, a register 204a and a reset counter 204b stores reset operation and number of times the reset operations are performed for the predetermined time period detecting the ignition ON/OFF state of the vehicle in accordance with an embodiment of the present disclosure. The register 204a in the location 033A indicates ignition ON/OFF state of the vehicle which is stored with value 01. The reset counter 204b indicates the number of times the reset operation is performed with the flag value as 00 at location 0339.

Figures 5 illustrates a flowchart of a method for controlling one or more relays 202 (202a, and 202b) in a vehicle, in accordance with an embodiment of the present disclosure. At step 501, the control unit 101 reads the ignition status (normal Ignition ON to OFF or reset state) from the predefined register 204a in the memory unit 203. At step 502, reset operation occurrence in the previous ignition cycle is checked. If reset operation has not occurred, the first timer 205a with predefined time is started at step 503. At step 504, check if predefined time has elapsed. At 505 if time has elapsed, flag value ‘0’ is stored at the reset counter 204b in the predefined register 204a in memory unit 203. At step 506, if a reset operation has occurred, the number of times the reset operation had occurred is obtained. At step 507, check if number of times reset operation has occurred is greater than preset value. If not, reset counter 204b is incremented at step 508 by a predefined value. At step 509 if number of reset operation is greater than a preset value, one or more components are powered OFF for a predetermined amount of time.

An example is illustrated herein to control the one or more relays 202 from chattering thereafter welding, as an example embodiment of the present disclosure. The control unit 101 detects the ignition OFF state of the vehicle by reading the flag value in the register 204a during ignition cycle. If the flag value in the register 204a is ‘1’, the normal ignition OFF state of the vehicle is detected. If the flag value in the register 204b is ‘0’, the reset operation has occurred on the control unit 101 in the previous ignition cycle. Upon detecting the flag value as ‘0’, the number of times the control unit 101 has undergone the reset operations is obtained from the reset counter 204b which is incremented by 1 each time the reset operation is achieved. Here, the first timer 205a of a range 1 to 3 seconds is initialized. If the reset operations have occurred for a certain number of times, for example 6, the glow plug 207 output is powered OFF for a predefined time set by the second timer 205b. Thus, the relay 202 is saved from chattering thereupon from welding. Upon the elapse of the fixed amount of time set by the second timer 205b, the glow plug 207 is made on again. If flag value of ignition OFF in the register 204a equals to ‘1’ which indicates the normal ignition OFF state of the vehicle and if flag value ‘0’ indicates a reset condition.

Additionally, various advantages of the present disclosure are illustrated herein.

Embodiment of the present disclosure avoid the damage that can be caused to one or more relays due to chattering and welding during reset operations caused due to low battery condition.

Embodiments of the present disclosure provides a method to control the one or more relays by powering OFF or shutting down the one or more components for the predetermined amount of time during low battery conditions.

Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Referral Numerals:
Reference Number Description
100 Inputs
100a Coolant Temperature Sensor
102 Exhaust Gas Recirculation (EGR) Modulator
103 Malfunction Indicator Lamp (MIL)
104 Check Engine Lamp (CEL)
105 Glow Plug (GP) Lamp
106 Glow Plug (GP) Relay
107 Fan Controller Relay
101 Control Unit
200 System
201 Battery
202 (,202a and 202b) Relays
203 Memory Unit
204a Register
204b Reset Counter
205a First Timer
205b Second Timer
206 Comparator
207 Glow Plugs
208 Fans