Claims:We claim:
1. A controller (110) to regulate engine speed (118) in a vehicle, said controller (110) configured to monitor engine speed (118) from signals received from an engine speed sensor (102) and comprises a memory element (104) prestored with a maximum speed limit (128) for said engine, characterized in that, said controller (110) further configured to:
store, at least one threshold speed limit (106) whose value is lesser than that of said maximum speed limit (128), in said memory element (104),
detect said engine speed (118) exceeding said at least one threshold speed limit (106) and regulate said engine speed (118) at said at least one threshold speed limit (106) for a corresponding set threshold time duration (108).

2. The controller (110) as claimed in claim 1, wherein an alert signal is triggered when said monitored engine speed (118) exceeds each of said at least one threshold speed limit (106).

3. The controller (110) as claimed in claim 1, wherein said at least one threshold speed limit (106) comprises a first speed limit (124) and a second speed limit (126), wherein said controller (110) sequentially regulates said engine speed (118) at said first speed limit (124) and at said second speed limit (126).

4. The controller (110) as claimed in claim 3, wherein said first speed limit (124) is regulated for a corresponding first time duration (122) and said second speed limit (126) is regulated for a corresponding second time duration.

5. The controller (110) as claimed in claim 1, regulates said engine speed (118) below said maximum speed limit (128) when said engine speed (118) is detected to exceed each of said at least one threshold speed limit (106).

6. A method for regulating engine speed (118) in a vehicle through a controller (110), said controller (110) comprises a memory element (104) prestored with a maximum speed limit (128) for said engine, said method comprises the steps of:
monitoring engine speed (118) from signals received from an engine speed sensor (102), characterized by,
detecting said engine speed (118) exceeding at least one threshold speed limit (106), and regulating said engine speed (118) at each of said at least one threshold speed limit (106) for a corresponding set threshold time duration (108), each of said at least one threshold speed limit (106) is prestored in said memory element (104).

7. The method as claimed in claim 6, comprises triggering an alert signal and notifying a driver of said vehicle on every occasion of said monitored engine speed (118) exceeds said at least one threshold speed limit (106).

8. The method as claimed in claim 6, wherein said at least one threshold speed limit (106) comprises a first speed limit (124) and a second speed limit (126), wherein said method comprises sequentially regulating said engine speed (118) at every threshold speed limit (106).

9. The method as claimed in claim 8, comprises regulating said engine speed (118) at said first speed limit (124) for a corresponding first time duration (122) when said engine speed (118) is detected to exceed said first speed limit (124), and regulating said engine speed (118) at said second speed limit (126) for a corresponding second time duration when said engine speed (118) is detected to exceed said second speed limit (126).

10. The method as claimed in claim 6, comprises regulating said engine speed (118) below said maximum speed limit (128) when said engine speed (118) is detected to reach said maximum speed limit (128) after exceeding each of said at least one threshold speed limit (106).
, Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:

Field of the invention:
[0001] The present invention relates to a controller and method to regulate engine speed in a vehicle.

Background of the invention:
[0002] All the engine systems have the functionality of limiting the engine speed based on the cylinder capacity/size of the engine. Generally, the limit speed is around 10000 RPM for two wheelers with single cylinder and 7000 RPM for three wheelers and Quadracycles. This is to protect the engine from being damaged or being rough. Currently this limitation is being done only when the engine speed reaches max RPM at once. But there is a small chance the engine gets damaged if the driver doesn’t react by reducing the RPM. All engines have the tendency of damages at maximum operating range/speed and hence has to be limited even before reaching that danger zone. But usually the warning or limitation is done only when the speed reaches that danger zone and if reaction is slower from the driver to reduce the RPM, most of the time the damage will happen to engine and components.

[0003] A patent literature 691/CHENP/2010 discloses a method and apparatus for monitoring the function of a rotational speed regulator. The invention relates to a method and an apparatus for monitoring a function of a rotational speed regulating means of an internal combustion engine. Here, an exceeding of the rotational speed is detected if an actual rotational speed of the internal combustion engine exceeds a setpoint rotational speed by more than a predefined threshold value. If an exceeding of the rotational speed is detected, a manipulated variable (S) of the rotational speed regulating means is limited to a maximum manipulated variable which drops over time.

Brief description of the accompanying drawings:
[0004] An embodiment of the disclosure is described with reference to the following accompanying drawing,
[0005] Fig. 1 illustrates a block diagram of a controller to regulate engine speed in a vehicle and a plot, according to an embodiment of the present invention, and
[0006] Fig. 2 illustrates a method for regulating engine speed in a vehicle through a controller, according to the present invention.

Detailed description of the embodiments:
[0007] Fig. 1 illustrates a block diagram of a controller to regulate engine speed in a vehicle and a plot, according to an embodiment of the present invention. The controller 110 configured to monitor engine speed 118 from signals received from an engine speed sensor 102 and comprises a memory element 104 prestored with a maximum speed limit 128 for the engine, characterized in that, the controller 110 further configured to store, at least one threshold speed limit 106 whose value is lesser than that of the maximum speed limit 128, in the memory element 104. While in operation, the controller 110 detects the engine speed 118 exceeding the at least one threshold speed limit 106 and regulates the engine speed 118 at the at least one threshold speed limit 106 for a corresponding set threshold time duration 108. Thus, the controller 110 regulates or maintains the engine speed 118 before allowing the engine speed 118 to increase towards the maximum speed limit 128. Each of the at least one threshold speed limit 106 and the corresponding set threshold time duration 108 are prestored in the memory element 104 and our changeable as to fine-tune the control.

[0008] The controller 110 refers to computing devices/units comprising components such as memory element 104 such as Random Access Memory (RAM) and/or Read Only Memory (ROM), Analog-to-Digital Converter (ADC), Digital-to-Analog Convertor (DAC), clocks, timers and a processor (capable of implementing machine learning) connected with the each other and to other components through communication bus channels. The components mentioned are just for understanding and the controller 110 may have more or less components as per requirement. The memory element 104 is prestored with logics or instructions or programs or applications or thresholds or values which is accessed by the processor as per the defined routines. The internal components of the controller 110 are not explained for being state of the art, and the same must not be understood in a limiting manner. The controller 110 is capable to communicate through wired and wireless means such as but not limited to Global System for Mobile Communications (GSM), 3G, 4G, 5G, Wi-Fi, Bluetooth, Ethernet, serial networks, Universal Serial Bus (USB) cable, micro-USB, and the like.

[0009] The controller 110 is also configured to trigger alert signal when the monitored engine speed 118 exceeds each of the at least one threshold speed limit 106. The alert is provided through any output means 112 such as audio, visual (such as blinking pattern or colors), display (such as instrument cluster), haptic and combination thereof. In accordance to an embodiment of the present invention, the at least one threshold speed limit 106 comprises a first speed limit 124 and a second speed limit 126. The controller 110 sequentially regulates the engine speed 118 at the first speed limit 124 and at the second speed limit 126. Still further, the first speed limit 124 is regulated for a corresponding first time duration 122 and the second speed limit 126 is regulated for a corresponding second time duration (not shown). Furthermore, the controller 110 regulates the engine speed 118 below the maximum speed limit 128 when the engine speed 118 is detected to exceed each of the at least one threshold speed limit 106. In simple words, if the engine speed 118 has already crossed all the set speed limits, then the controller 110 limits/regulates the engine speed 118 below the maximum speed limit 128 of the engine. The controller 110 is configurable to adjust the threshold speed limits 106 and not limited only to two, i.e. the controller 110 may use one, three, four and the like.

[0010] In accordance to an embodiment of the present invention, a working of the controller 110 is explained with the help of a plot 120, and the same must not be understood in limiting manner. The plot 120 comprises an X-axis 114 which denotes time in suitable units, and the Y-axis 116 which denotes engine speed 118 in suitable units. The controller 110 monitors the engine speed 118 for an acceleration (or speed) and two different threshold speed limit/level 106 are identified well before the maximum speed limit 128 (or operating RPM). When the engine speed 118 exceeds/crosses the first speed limit 124, the engine speed 118 is maintained/regulated (refer the dotted closed boundary) at the first speed limit 124 for some the first time duration 122. At the same time, the controller 110 alerts the driver that the engine speed 118 is heading towards the maximum speed limit 128 (or danger operating RPM/zone). There is no damage to the engine at the first threshold speed 124 but the speed regulation is done to alert the driver. After the first time duration 122 is elapsed, the controller 110 allows the engine speed 18 to increase till the second speed limit 126 is reached. The plot 120 is not shown with the second speed limit 126 but can be assumed to be below the maximum speed limit 128 and above the first speed limit 124. When the second speed limit 126 is crossed, the controller 110 again limits or regulates (can be assumed similar to the previous dotted closed boundary) the engine speed 118 at the second speed limit 126 for second time duration. At the same time, a second alert is sent to the driver (such as warning) to maintain the engine speed 118 instead of increasing further. If the driver still increases the engine speed 118 after the elapsing of the second time duration, the controller 110 allows the same but finally limits till or below the maximum speed limit 128. The controller 110 reinitiates the process once the engine speed 118 falls below the first speed limit 124.

[0011] In accordance to an embodiment of the present invention, the at least one threshold speed limit 106 and the corresponding threshold time duration 108 are configurable directly on the vehicle or through any computing device connected to the vehicle. For example, a smartphone connected to the controller 110 through wired or wireless means or buttons provided in the vehicle or any other testing diagnostic devices. Further, the vehicle is any one selected from a group comprising a two-wheeler such as scooter, motorcycle, a three-wheeler such as autorickshaw, a four wheeler such as cars, and multi-wheel vehicles. Further, the present invention is equally suitable for a snowmobile or water sports based vehicles.

[0012] Fig. 2 illustrates a method for regulating engine speed in a vehicle through a controller, according to the present invention. The controller 110 comprises the memory element 104 prestored with the maximum speed limit 128 for the engine. The method comprises plurality of steps, of which a step 202 comprises monitoring the engine speed 118 from signals received from the engine speed sensor 102. The method is characterized by, a step 204 which comprises detecting the engine speed 118 exceeding at least one threshold speed limit 106, and regulating the engine speed 118 at each of the at least one threshold speed limit 106 for the corresponding set threshold time duration 108. Each of the at least one threshold speed limit 106 and the corresponding set threshold time duration 108 are prestored in the memory element 104.

[0013] The method further comprises triggering the alert signal and notifying the driver of the vehicle on every occasion of the monitored engine speed 118 exceeding the at least one threshold speed limit 106. The at least one threshold speed 106 comprises the first speed limit and the second speed limit 126. The method sequentially regulates the engine speed 118 at every threshold speed limit 106. The method comprises regulating the engine speed 118 at the first speed limit 124 for the corresponding first time duration 122 when the engine speed 118 is detected to exceed the first speed limit 124, followed by regulating the engine speed 118 at the second speed limit 126 for the corresponding second time duration when the engine speed 118 is detected to exceed the second speed limit 126. The regulation of engine speed 118 is done sequentially, i.e. the engine speed 118 is regulated at the second speed limit 126 only after the first speed limit 124 has been exceeded. The method finally comprises regulating the engine speed 118 below the maximum speed limit 128 when the engine speed 118 is detected to reach the maximum speed limit 128 after exceeding each of the at least one threshold speed limit 106. The at least one threshold speed limit 106 is selected from one, two, three and the like.

[0014] The step 204 is explained with example considering two threshold speed limits 106. Consider the first speed limit 124 and the second speed limit 126 are prestored in the memory element 104. While monitoring the engine speed 118 at step 202, at step 206 if the controller 110 detects the engine speed 118 has exceeded the first speed limit 124, the method comprises regulating the engine speed 118 at the first speed limit 124 for the first time duration 122. Once the first time duration 122 has elapsed, the engine speed 118 is allowed to increase. At step 208, if the engine speed 118 is detected to be exceeding the second speed limit 126, then the method comprises regulating the engine speed 118 at the second speed limit 126 for the second time duration. Once, the second time duration is elapsed, the method comprises allowing the increase in engine speed 118 only to the maximum speed limit 128 and not beyond the same, as described in step 210. At step 206 and 208, the method also triggers the alert to warn and indicate the driver to reduce the engine speed 118 to avoid damage to the engine. The method is stored as logic or set of instructions in the controller 110, which when executed, performs all the above steps.

[0015] In accordance to an embodiment of the present invention, the controller 110 and method aids in sequentially limiting the maximum speed of the engine. An indication to the driver is provided well in advance, that the engine is going to the maximum operating limit, so that the driver can maintain the safe operating point of the engine without reaching the maximum speed limit 128. Thus, the controller 110 and the method gives a warning to the driver well in advance that the engine is going to danger zone and needs to be prevented before any damage happens.

[0016] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.