Description:Field of the invention

[0001] The present invention relates to a control system for a linear actuator. More specifically, the present invention relates to a system and method for controlling a linear actuator without the need of position feedback.

Background of the invention

[0002] Traditional linear actuator-based systems incorporate position feedback mechanisms, frequently utilizing external sensors such as potentiometers or hall sensors to accurately ascertain the position of the output shaft. Despite their effectiveness in providing accurate position feedback, these conventional systems are burdened with significant drawbacks. Foremost among these challenges is the increased overall product cost attributed to the inclusion of external sensors, rendering these systems less economically viable. Moreover, prolonged usage of these sensors introduces wear and tear, necessitating maintenance and elevating the risk of sensor failures, thereby impacting the system's overall reliability.

[0003] The addition of extra mechanical components for feedback purposes not only introduces complexity to the system design but also raises concerns about mechanical failures. This heightened mechanical complexity, coupled with the need for additional manufacturing processes, leads to elevated manufacturing costs. Furthermore, the reliance on external sensors imposes limitations on the flexibility of these systems across varying travel distances of the output shaft. This limitation may compromise the adaptability of the system to diverse application requirements. Also, the spatial requirements for accommodating feedback sensors result in increased product packaging and printed circuit board (PCB) space, potentially hindering the integration of these systems into compact designs and applications with limited available space.

[0004] Further, the use of external sensors for the position feedback contributes to the overall cost of linear actuator-based systems. The need for specialized sensors and associated circuitry further contributes to a higher production expense and the continuous movement and operation can lead to wear and tear of the feedback sensor, impacting its reliability over time and introducing maintenance requirements. Traditional systems may face limitations in flexibility over the travel distances of the output shaft due to dependence on external sensors, restricting adaptability to varying application requirements.

[0005] Therefore, there is a need for a system and method for controlling a linear actuator which overcomes one or more drawbacks of the above-mentioned prior art.

Objects of the invention

[0006] An object of the present invention is to provide a system and method for controlling a linear actuator that does not require external position feedback sensors.

[0007] Another object of the present invention is to provide a system and method for controlling a linear actuator that perform self-calibration after every power-up.

[0008] Yet another object of the present invention is to provide a system and method for controlling a linear actuator that can configure the polarity of the system.

[0009] One more object of the present invention is to provide a system and method for controlling a linear actuator that facilitates the bidirectional movement of the linear actuator shaft within the specified voltage range.

[0010] Further object of the present invention is to provide a system and method for controlling a linear actuator which is cost-effective and reliable.

Summary of the invention

[0011] According to the present invention, a system and method for controlling a linear actuator is provided. The system may include a linear actuator, a motor for driving the linear actuator shaft, a microcontroller unit, a driver circuit, a memory unit and a current sensing unit. The microcontroller unit is configured to receive an input voltage signal in different forms from an ECU (Electronic Control Unit) or a manual switch of the vehicle. The driver circuit is provided for translating the input voltage signals from the microcontroller for controlling the movement of the shaft of the linear actuator. The input voltage signal corresponds to a stroke length of the linear actuator shaft and the output of the linear actuator shaft is a function of the time and the direction for which the linear actuator is activated. The time duration and the direction of the linear actuator is a function of the input voltage signal and the polarity of operation. The polarity of operation and current sensing occur during system initialization upon powering up.

[0012] The memory unit is provided for storing the last stable position of the linear actuator shaft. The current sensing unit is for determining an extreme position of the linear actuator shaft based on the last stable position in the memory unit. The current sensing is done during the initialisation of the system. The current sensing unit determine the extreme position of the linear actuator shaft by indicating a rise in the motor current such that the rise in the motor current corresponds to the position of the linear actuator shaft at one of an extreme end of the linear actuator.

[0013] The microcontroller unit utilizes a voltage-to-stroke length mapping to determine the position of the linear actuator shaft such that the higher voltages corresponding to increased stroke lengths and vice versa. The polarity of the system is preconfigured during the initialisation of the system and is adjustable through a software control. The software control enables the users to define a correlation between changes in the input voltage signal and the linear actuator movement. Specifically, users can configure the relationship to be either linear or inverse linear, allowing bidirectional movement of the linear actuator shaft within a specified voltage range.

[0014] In an aspect of the invention, the system operates at a supply voltage ranging between 12V and 24V. Specifically the system operates at a supply voltage ranging between 9V to 18V in a 12V vehicle architecture and a supply voltage ranging between 20V to 30V in a 24V vehicle architecture.

[0015] In an aspect of the invention, the input voltage signal level is configured between 0% to 100% of the supply voltage. The system is self-calibrated after each power up based on the stored position information.

[0016] In an aspect of the invention, a method for controlling the linear actuator in a system is provided. The method starts by initializing the system by powering up. The nearest end position of the linear actuator shaft is then determined based on the last stored position in the memory unit. After that the motor is activated towards the nearest end position. The motor current is monitored using a current sensing unit to determine an extreme position of the linear actuator shaft by indicating a rise in the motor current such that the rise in the motor current corresponds to the position of the linear actuator shaft at one of an extreme end of the linear actuator.

[0017] The motor is deactivated once a rise in current is detected, indicating the linear actuator is stalling at an extreme position. The polarity of the system is then configured using a software control for enabling the users to define a relationship between the input voltage signal and the linear actuator movement. The initialization of the system is completed by activating the motor for a desired duration and in a desired direction based on the current position of the linear actuator shaft and input voltage signal.

[0018] A change in the input voltage signal is then detected and received by a microcontroller unit from an ECU (Electronic Control Unit) or manual switch of the vehicle. The delta change in the input voltage signal is analysed to find out whether the change in voltage is positive or negative. The direction of the motor rotation is defined based on the analysed delta change. The required travel time for the linear actuator shaft is analysed and the motor is activated for the required travel time. The motor is deactivated once the travel time is complete and the position information of the linear actuator shaft saved in a memory unit. The process is then repeated for the next input voltage signal.

Brief Description of drawings

[0019] The advantages and features of the present invention will be understood better with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:

[0020] Figure 1 illustrates the schematic diagram of a linear actuator in accordance with the present invention;

[0021] Figure 2 illustrates a block diagram of the system for controlling a linear actuator in accordance with the present invention;

[0022] Figure 3 illustrates a method for controlling a linear actuator in accordance with the present invention; and

[0023] Figure 4 illustrates a method for initializing the system for controlling a linear actuator in accordance with the present invention.

Detailed description of the invention

[0024] An embodiment of this invention, illustrating its features, will now be described in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items.

[0025] The present invention relates to a control system for a linear actuator. More specifically, the present invention relates to a system and method for controlling a linear actuator.

[0026] The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.

[0027] The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.

[0028] Referring now to figures 1, and 2 a system (100) for controlling a linear actuator (70) in accordance with the present invention is provided. The system (100) is implemented on a vehicle specifically for controlling and adjusting the position of the head lamp unit of a vehicle. It may be obvious to a person skilled in the art to implement the system on any other units which requires a controlled linear movement. The system includes a linear actuator (70), a motor (50), a microcontroller unit (80), a driver circuit (40), a memory unit (30) and a current sensing unit (60).

[0029] The linear actuator (70) is positioned in a way that it allows to connect and control the movement of the headlamp unit. The linear actuator (70) may be positioned inside a headlamp housing or adjacent to the headlamp housing. It may be obvious to a person skilled in the art to position the linear actuator anywhere near the headlamp unit such as in vehicle interiors, inside the engine compartment, behind front bumper, chassis and the like. The linear actuator (70) may include mounting components such as brackets and couplings to secure the linear actuator in place and connect it to the headlamp unit.

[0030] The linear actuator (70) is connected to a motor (50) to drive the linear motion of a shaft (75) associated with the linear actuator (70). In the present embodiment, the motor (50) is an electric motor for driving the linear actuator shaft (75). In an embodiment, the linear actuator shaft (75) is movable using a lead screw mechanism (25) (figure 1). Specifically, the lead screw mechanism (25) facilitates the movement of the linear actuator shaft (75) by converting the rotational motion generated by the motor (50) into linear displacement. A person skilled an art can integrate various mechanisms, such as ball screws, rack and pinion, or belt drives, to achieve the same purpose.

[0031] The motor (50) is adapted to receive signal from the microcontroller unit (80) for controlling the movement or position of the linear actuator shaft (75). In the present embodiment, the microcontroller unit (80) is configured to receive an input voltage signal (10) from an ECU (Electronic Control Unit) (90) or a manual switch of the vehicle. The output or movement of the linear actuator shaft (75) is directly influenced by the input voltage signal (10) received by the microcontroller unit (80). By way of non-limiting example, the system (100) operates at a supply voltage ranging between 12V and 24V. The input voltage signal level (10) is configured between 0% to 100% of the supply voltage. Specifically, the system (100) accommodates a supply voltage ranging between 9V to 18V for a 12V vehicle architecture and a supply voltage ranging between 20V to 30V for a 24V vehicle architecture.

[0032] The supply voltage refers to the overall voltage provided to the system (100), which powers the components such as the motor (50), the microcontroller unit (80), and other elements of the system (100). It's the primary voltage source for the system's operation. For vehicles, this supply voltage matches the vehicle's electrical system voltage, which can be either a 12V system (common in most passenger vehicles) or a 24V system (in heavy-duty or commercial vehicles). In the present embodiment, the system (100) operates at a supply voltage ranging between 9V to 18V for a 12V vehicle architecture and between 20V to 30V for a 24V vehicle architecture, which accounts for variations in the vehicle's electrical system voltage under different operating conditions.

[0033] The input voltage signal, is a specific signal that the microcontroller unit receives, which dictates the operation of the linear actuator. This signal is used by the system to determine the position or movement of the headlamp unit by controlling the linear actuator. The input voltage signal can vary between 0% to 100% of the supply voltage, which allows the system to modulate the position of the headlamp unit based on the voltage level of the signal. The microcontroller unit processes this input voltage signal and, based on its level, generates control signals that regulate the motor driving the linear actuator.

[0034] The microcontroller unit (80) processes the input voltage signal (10) and generates the control signals to regulate the motor (50) and the movement of the linear actuator shaft (75). The ECU (Electronic Control Unit) or manual switch (90) of the vehicle generates the input voltage signal (10) that serves as a command or a control parameter for the linear actuator (70). The input voltage signal (10) is transmitted from the ECU (Electronic Control Unit) (90) or manual switch of the vehicle to the microcontroller unit (80) through a communication interface (not shown in figure). A person skilled in the art can utilize the communication interface such as UART, SPI, or CAN (Controller Area Network) depending on the system (100) requirements.

[0035] The microcontroller unit (80) interprets the incoming input voltage signal (10) by creating a functional relationship between the input voltage signal (10) and the movement of the linear actuator shaft (75). Particularly, the microcontroller unit (80) utilizes a voltage-to-stroke length mapping to determine the position of the linear actuator shaft (75) such that the higher voltages corresponding to increased stroke lengths and vice versa. By way of non-limiting example, the stroke length of the linear actuator (70) is set at 8mm and the system is configured to handle the supply voltage level ranging between 12V and 24V. The microcontroller unit (80) interprets the input voltage signal (10) in a linear manner such that each input voltage signal (10) corresponds to a specific stroke length.

[0036] By the way of non-limiting example, let's consider the case of a 12V vehicle architecture with a supply voltage ranging between 9V to 18V where the input voltage signal (10) can range between 0% to 100% of the system supply voltage. Considering a specific scenario where the system is adapted to work with a supply voltage extending from 9V to 18V, whereby the input voltage signal level (10) can also be modulated from 0V to 15V, reflecting 0% to 100% of the system's operational supply voltage range. Based on the preconfigured polarity, the voltage-to-stroke length mapping is performed that translates the input voltage signal into specific linear actuator movements. Polarity refers to the orientation or direction of the control in relation to the input voltage signal and its effect on the linear actuator's movement. Polarity determines how the linear actuator responds to the input voltage signal, particularly in terms of the direction of movement (extending or retracting the actuator shaft). For example, the user can define the polarity such that with 0V input voltage signal represents 0 mm stroke length and 15V input voltage signal represents 8mm stroke length of the linear actuator shaft (75). In such case, the microcontroller unit (80) provides a linear relationship indicating a proportional connection between the input voltage signal (10) and the resulting position of the linear actuator shaft (75). As the input voltage signal increases from 0V to 15V, the stroke length of the linear actuator shaft (75) proportionally increases from 0 mm to 8 mm.

[0037] In the present embodiment, the polarity of the system (100) is adjustable through a software control. The adjustable polarity enables the users to define the correlation between changes in the input voltage signal (10) and the movement of the linear actuator shaft (75). Specifically, users can configure the relationship to be either linear or inverse linear, allowing bidirectional movement of the linear actuator shaft (75) within a specified voltage range. The modification is achieved by changing the polarity of the system (100), resulting in a configuration where the input voltage signal of 15V corresponds to 0 mm, and a 0V corresponds to 8 mm stroke length of the linear actuator shaft (75). In such case, as the input voltage signal changes or decreases from 15V to 0V, the stroke length of the linear actuator shaft (75) proportionally decreases or changes from 0 mm to 8 mm.

[0038] In another example, consider the case of 24V architecture with a supply voltage ranging from 20V to 30V. Considering a specific scenario where the system supply voltage is fixed at 27V, within which the input voltage signal (10) can be modulated between 0% and 100% relative to the supply voltage. This modulation enables the input voltage signal to vary from 0V to 27V. The polarity is defined such that the input voltage signal of 0V corresponds to a 0mm stroke length and 27V corresponds to 8mm stroke length. In this scenario, the microcontroller unit (80) provides a linear relationship indicating a proportional connection between the input voltage signal (10) and the resulting position of the linear actuator shaft (75). As the input voltage signal increases from 0V to 27V, the stroke length of the linear actuator shaft (75) proportionally increases from 0 mm to 8 mm. If the polarity is reversed using the software control, the change in polarity of the system results in a configuration where the input voltage signal of 27V corresponds to 0 mm, and a 0V corresponds to 8 mm stroke length of the linear actuator shaft (75).

[0039] In the present embodiment, the polarity of the system (100) is configured during the initialization of the system (100). In an alternate embodiment, the polarity of the system (100) is configured after or before the initialization of the system (100).

[0040] Furthermore, if the input voltage signal (10) is set to be in a mid-point within the specified range in the 12V or 24V vehicle architecture, the microcontroller unit (80) maintains the linear relationship and the stroke length is expected to be at a mid-point between 0 mm and 8 mm. If the input voltage signal (10) changes within the specified range, the microcontroller unit (80) adjusts the mapping accordingly and the linear actuator (70) responds accurately to the variations in the input voltage signal (10).

[0041] Further, the driver circuit (40) is used for translating the input voltage signals (10) received from the microcontroller unit (80). These input voltage signals (10) functions as commands from the microcontroller unit (80) to control the movement of the linear actuator shaft (75). The input voltage signals (10) from the microcontroller unit (80) are in the form of electrical voltage levels. The driver circuit (40) convert these electrical voltage levels into specific control signals suitable for driving the motor (50) connected to the linear actuator (70). The driver circuit (40) interfaces with the motor (50) and drives the linear actuator shaft (75) and translates the control signals into instructions for the motor (50) to determine the factors such as speed, direction, and duration of the movement of the linear actuator shaft (75).
[0042] The system (100) is self-calibrated after each power up based on the stored position information of the linear actuator (70). The position information of the linear actuator (70) is stored in a memory unit (30). The memory unit (30) stores the last stable position of the linear actuator shaft (75). In the present embodiment, the memory unit (30) is a non-volatile storage medium that persist the stored position information of the linear actuator shaft (75) even when the power to the system (100) is turned off.

[0043] The system (100) further includes a current sensing unit (60). The current sensing unit (60) is used for determining the extreme position of the linear actuator shaft (75). Specifically, the current sensing unit (60) utilizes the last stable position of the linear actuator shaft (75) stored in the memory unit (30) as a reference point for determining the extreme position of the linear actuator shaft (75). The extreme position refers to one of the two outermost points reached by the linear actuator shaft (75) during its movement. These positions can be either the fully retracted state or fully extended state of the linear actuator shaft (75).

[0044] The current sensing unit (60) continuously monitor the electrical current flowing through the motor (50) that drives the linear actuator shaft (75) during the initialization of the system after every power up. The current sensing unit (60) recognizes a rise in motor current which occurs when the linear actuator shaft (75) reaches one of its extreme positions. The rise in current is a result of the increased mechanical resistance faced by the motor (50) when the linear actuator shaft (75) approaches or reaches one of the extreme ends. To overcome the high resistance and to move the linear actuator (70), the motor (50) has to deliver consume more current resulting in a rise in the current. The rise in motor current is correlated with the position of the linear actuator shaft (75) indicating that the linear actuator has reached one of its extreme positions.

[0045] Referring now to figure 3, a method (200) for controlling a linear actuator (70) in accordance with the present invention is illustrated. For the sake of brevity, the method (200) is described in conjunction with the system (100) referred in figures 1 and 2 as described above.

[0046] The method (200) starts at step 210.

[0047] At step 220, initializing of the system (100) is performed by powering up and retrieving a last stored position of the linear actuator shaft (75) from the memory unit (30).

[0048] At step 230, the input voltage signal (10) received by the microcontroller unit (80) from the Electronic Control Unit (ECU) or the manual switch (90) of the vehicle is monitored to detect any change in the input voltage signal (10).

[0049] At step 240, the delta change in the input voltage signal (10) is analysed. The delta change in the input voltage signal (10) is analysed to find out whether the change in voltage is positive or negative. The delta change refers to the variation in the input voltage signal (10) between two sequential moments in time, indicating whether the input voltage signal has increased (positive delta change) or decreased (negative delta change) from the previous value. The corresponding action in case of delta change positive or negative is preset during the initialization of the system (100) by configuring the polarity.

[0050] Further at step 250, the motor (50) is activated for a predefined duration and in a predefined direction based on the delta change of the input voltage signal (10). The direction of the motor (50) rotation is defined based on the analysed delta change and can be preset by configuring the polarity. Further, the required travel time for the linear actuator shaft (75) is analysed and the motor (50) is activated for the required travel time. The motor (50) facilitates the movement of the linear actuator shaft (75) in accordance with the direction of the motor's (50) rotation and the current position of the linear actuator shaft (75). For example, if the delta change is positive, the direction of rotation of the motor (50) can be set clockwise and accordingly the linear actuator shaft (75) can be moved in a direction corresponding to the rotational direction of the motor (50). The motor (50) is deactivated once the travel time is complete and the position information of the linear actuator shaft (75) saved in the memory unit

[0051] At step 260, the system (100) waits for the next input voltage signal (10) to repeat the process.

[0052] The method (200) ends at step 270.

[0053] In an aspect, a method (300) of initializing the system (100) in accordance with the present invention is also provided.

[0054] The method (300) starts at step 310.

[0055] At step 320, the polarity of the system (100) is configured using the software control to define the relationship between an input voltage signal (10) and the movement direction of the linear actuator (70). Further defines the direction of the motor (50) rotation based on a delta change of the input voltage signal (10).

[0056] At step 330, the nearest end position of the linear actuator shaft (75) is determined based on the last stored position in the memory unit (30).

[0057] At step 340, the motor (50) is activated towards the nearest end position.

[0058] At step 350, the motor current is monitored using a current sensing unit (60) to determine an extreme position of the linear actuator shaft (75) by indicating a rise in the motor current such that the rise in the motor current corresponds to the position of the linear actuator shaft (75) at one of an extreme end of the linear actuator (70).

[0059] At step 360, the motor (50) is deactivated once a rise in current is detected, indicating the linear actuator (70) is stalling at an extreme position.

[0060] At step 370, the motor (50) is activated for a predefined duration and in a predefined direction based on the current position of the linear actuator shaft (75) and the input voltage signal (10).

[0061] The initialization method completes at step 380 and the method ends at step 390.

[0062] An example showing the working of the invention in system (100) having a supply voltage range between 9V to 18V in a 12V vehicle architecture is given below. Consider a specific scenario where the system supply voltage is fixed at 15V. The polarity is defined such that a 0V input voltage signal (10) corresponds to a 0mm stroke length, and 15V input voltage signal (10) corresponds to an 8mm stroke length of the linear actuator shaft (75).

[0063] During system initialization, the position of the linear actuator shaft (75) is checked. If for example, the position of the linear actuator shaft (75) is at 5mm stroke length, the system (100) automatically moves the linear actuator shaft (75) towards the 8mm position, halting at the extreme end position.

[0064] Following initialization, the microcontroller unit (80) monitors any change in the input voltage signal (10). The monitoring process involves detecting the delta change in the input voltage signal, which signifies the magnitude and direction of voltage change between consecutive measurements. This delta change analysis helps ascertain whether the input voltage has experienced an increase (indicating a positive delta change) or a decrease (indicating a negative delta change) relative to its previous value. For example, if the input voltage signal increases from 0V to 15V, the system (100) interprets the delta change as positive (this can be defined by polarity configuration using the software control), causing the linear actuator shaft (75) to move towards the 8 mm stroke length. If the input voltage signal reduces from 15V to 0V, the linear actuator shaft (75) move towards the 0mm starting position.

[0065] Thus, the present system has an advantage of providing a system and a method for controlling a linear actuator that overcomes the limitations of traditional linear actuator-based systems. The system does not require any external position feedback sensors to determine the position of the linear actuator shaft. Further, the system performs self-calibration after every power-up, however the position of the linear actuator will be stored in the non-volatile memory and the system can determine the last position of the linear actuator shaft based on the position stored in the memory unit. The system also facilitates the bidirectional movement of the linear actuator shaft within the specified voltage range.

[0066] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the claims of the present invention.
, Claims:We Claim:

1. A method (200) for controlling a linear actuator (70) in a system (100), the method (200) comprising steps of:

initializing the system (100) by powering up and retrieving a last stored position of the linear actuator shaft (75) from a memory unit (30);
monitoring the input voltage signal (10) received by a microcontroller unit (80) from an Electronic Control Unit (ECU) or the manual switch (90) of the vehicle to detect any change in the input voltage signal (10);
analysing the delta changes in the input voltage signal (10);
activating a motor (50) for a predefined duration and in a predefined direction based on the delta change of the input voltage signal (10), the motor (50) facilitates the movement of the linear actuator shaft (75) in accordance with the direction of the motor's (50) rotation and the current position of the linear actuator shaft (75); and
waiting for the next input voltage signal (10) to repeat the process.

2. The method (200) for controlling a linear actuator (70) in a system (100) as claimed in claim 1, wherein the method (300) of initializing the system (100) comprising the steps of:
configuring the polarity of the system (100) using a software control to define the relationship between an input voltage signal (10) and the movement direction of the linear actuator (70) and defining the direction of the motor (50) rotation based on a delta change of the input voltage signal (10);
determining the nearest end position of the linear actuator shaft (75) based on the last stored position in the memory unit (30);
activating the motor (50) towards the nearest end position;
monitoring the motor current using a current sensing unit (60) to determine an extreme position of the linear actuator shaft (75) by indicating a rise in the motor current such that the rise in the motor current corresponds to the position of the linear actuator shaft (75) at one of an extreme end of the linear actuator (70);
deactivating the motor (50) once a rise in current is detected, indicating the linear actuator (80) is stalling at an extreme position;
activating the motor (50) for a predefined duration and in a predefined direction based on the current position of the linear actuator shaft (75) and the input voltage signal (10); and
completing initialization of the system (100).

3. The method (200) for controlling a linear actuator (70) in a system (100) as claimed in claim 1, wherein after the activation of the motor (50), the microcontroller unit (80) analyses the required travel time for the linear actuator shaft (75), deactivates the motor (50) once the travel time is complete and saves the position information in the memory unit (30).

4. The method (200) for controlling a linear actuator (70) in a system (100) as claimed in claim 1, wherein the delta change is the variation in the input voltage signal (10) between two sequential moments in time, indicating whether the input voltage signal (10) has increased (positive delta change) or decreased (negative delta change) from a previous value.

5. The method (200) for controlling a linear actuator (70) in a system (100) as claimed in claim 1, wherein the microcontroller unit (80) utilizes a voltage-to-stroke length mapping to determine the position of the linear actuator shaft (75) such that the higher voltages corresponding to increased stroke lengths and vice versa.

6. The method (200) for controlling a linear actuator (70) in a system (100) as claimed in claim 2, wherein the polarity of the system (100) is configured before/after or during the initialization of the system (100) and the polarity of the system (100) is adjustable through a software control, enabling users to configure the relationship between changes in the input voltage signal (10) and the linear actuator (70) movement to be either linear or inverse linear, allowing bidirectional movement of the linear actuator shaft (75) within a specified voltage range.

7. A system (100) for controlling a linear actuator (70), the system (100) comprising:
a motor (50) for driving a linear actuator shaft (75); and
a microcontroller unit (80) configured to receive an input voltage signal (10) in different forms from an ECU (Electronic Control Unit) (90) or a manual switch of the vehicle,
characterized in that, the system (100) comprises:
a driver circuit (40) for translating the input voltage signals (10) from the microcontroller unit (80) for controlling the movement of the linear actuator shaft (75);
a memory unit (30) for storing the last stable position of the linear actuator shaft (75); and
a current sensing unit (60) for determining an extreme position of the linear actuator shaft (75) during the initialisation of the system (100) upon powering up based on the last stable position in the memory unit (30).

8. The system (100) for controlling a linear actuator (70) as claimed in claim 7, wherein the input voltage signal (10) corresponds to a stroke length of the linear actuator shaft (75).

9. The system (100) for controlling a linear actuator (70) as claimed in claim 7, wherein the output of the linear actuator shaft (75) is a function of the time for which the linear actuator (70) is activated and the direction in which the linear actuator (70) is activated.

10. The system (100) for controlling a linear actuator (70) as claimed in claim 9, wherein the time duration and direction of the linear actuator (70) is a function of the input voltage signal (10) and the polarity of operation, wherein the polarity of operation occurs during the initialization of the system (100).

11. The system (100) for controlling a linear actuator (70) as claimed in claim 7, wherein the microcontroller unit (80) utilizes a voltage-to-stroke length mapping to determine the position of the linear actuator shaft (75) such that the higher voltages corresponding to increased stroke lengths and vice versa.

12. The system (100) for controlling a linear actuator (70) as claimed in claim 10, wherein the polarity of the system (100) is determined before/after or during the initialization of the system (100) and the polarity of the system (100) is adjustable through a software control, enabling users to configure the relationship between changes in the input voltage signal (10) and the linear actuator (70) movement to be either linear or inverse linear, allowing bidirectional movement of the linear actuator shaft (75) within a specified voltage range.

13. The system (100) for controlling a linear actuator (70) as claimed in claim 7, wherein the current sensing unit (60) determine the extreme position of the linear actuator shaft (75) by indicating a rise in the motor current such that the rise in the motor current corresponds to the position of the linear actuator shaft (75) at one of an extreme end of the linear actuator (70).

14. The system (100) for controlling a linear actuator (70) as claimed in claim 7, wherein the system (100) operates at a supply voltage level ranging between 12V and 24V.
15. The system (100) for controlling a linear actuator (70) as claimed in claim 7, wherein the input voltage signal (10) level is configured between 0% to 100% of the supply voltage.

16. The system (100) for controlling a linear actuator (70) as claimed in claim 7, wherein the system (100) is adapted to accommodate an input voltage signal (10) ranging between 9V to 18V for a 12V vehicle architecture and an input voltage signal (10) ranging between 20V to 30V for a 24V vehicle architecture.

17. The system (100) for controlling a linear actuator (70) as claimed in claim 8, wherein the stroke length of the linear actuator shaft (75) ranges between 0 mm and 8 mm.

18. The system (100) for controlling a linear actuator (70) as claimed in claim 8, wherein each incremental volt increase in the input voltage signal (10) corresponds to a proportional increase or decrease in the linear actuator shaft's (75) position.

19. The system (100) for controlling a linear actuator (70) as claimed in claim 7, wherein the system (100) is self-calibrated after each power up based on the stored position information.