Control unit for emulating gravitational acceleration in a vehicle and associated method

Abstract

A control unit (1) is designed to emulate gravitational acceleration in a vehicle, the control unit (1) communicating with the vehicle's braking system (2). The control unit (1) is designed to receive a gradient from at least one sensor (3) that communicates with the control unit. The control unit determines a phantom gradient based on a user preference, determines a gravitational acceleration corresponding to the phantom gradient, and provides a torque to emulate the gravitational acceleration based on a brake pedal position and the gradient.

Description

[0001] The following specification describes and defines the nature of this invention and the manner in which it is to be carried out. Field of invention

[0002] The present disclosure relates to a control unit designed to emulate gravitational acceleration in a vehicle.

[0003] When driving an automatic car in city traffic, the driver frequently switches between the accelerator and brake pedals. Constant and repeated pedal switching can lead to driver fatigue. Driver fatigue impairs driving ability, manifesting as slower reaction times, reduced steering performance, a decreased ability to maintain a safe distance from the vehicle ahead, and an increased tendency to be mentally distracted from the driving task. Shifting attention and cognitive processing away from the driving task is not a conscious, well-planned decision, but rather a semi-autonomous mental process of which the driver is only vaguely aware. Fatigue is a significant contributing factor in a large proportion of traffic accidents.

[0004] Driver assistance systems can significantly improve vehicle safety by integrating driver assistance functions into the vehicle. The present disclosure proposes a driver assistance system that reduces the driver's dependence on the accelerator pedal under urban driving conditions.

[0005] The experience of driving downhill is significantly more pleasant than navigating city traffic. This is primarily due to the reduced reliance on the accelerator pedal when descending a hill. Driving downhill allows the driver to effortlessly control the vehicle's speed using only the brake pedal. This operational efficiency enhances driving comfort and makes driving downhill more enjoyable than driving in the city. This hypothesis supports the core concept presented in the present invention. This invention aims to emulate the experience of driving downhill under urban driving conditions by enabling the driver to control the vehicle's speed using only the brake pedal, thereby providing a driving sensation equivalent to driving down a hill.

[0006] According to the prior art, a one-pedal driving feature is a known feature that allows the driver to accelerate, decelerate, and hold a stationary position using only the accelerator pedal. This feature eliminates the need for the driver to switch between depressing the accelerator and brake pedals to decelerate, stop, and hold the vehicle at a stationary position.

[0007] Normally, the brake pedal is used exclusively to decelerate the vehicle. To implement the present disclosure, the brake pedal is divided into two distinct ranges: an acceleration range and a deceleration range. The boundary between these ranges is referred to as the "virtual zero." Releasing the pedal so that it is depressed less than the "virtual zero" results in the vehicle accelerating, while depressing the pedal beyond the "virtual zero" results in the vehicle decelerating. To maintain a constant speed (neither accelerating nor decelerating), the driver must keep the pedal at the "virtual zero."Considering the challenge for drivers to position the pedal precisely at the virtual zero point, a "sailing range" was defined around it, within which the deceleration and acceleration effects are negligible. Brief description of the attached drawings

[0008] One embodiment of the invention is described with reference to the following accompanying drawings: Fig. Figure 1 shows a control unit designed to emulate gravitational acceleration in a vehicle, according to an embodiment of the present disclosure. Fig. Figure 2 illustrates a method for emulating gravitational acceleration in a vehicle according to an embodiment of the present disclosure. Fig. Figure 3 is a graphical representation of the input rod stroke of the brake pedal as a function of acceleration according to an embodiment of the present disclosure. Detailed description of the drawings

[0009] The present invention will now be described by way of example with reference to the accompanying drawings. In all figures, identical or corresponding elements may be generally designated by the same reference numerals. These illustrated embodiments are intended to illustrate the invention and are in no way to be understood as limiting. It is also understood that the figures are not necessarily to scale and that the embodiments are sometimes shown by means of graphic symbols, indicated lines, diagrams, and partial views. In certain cases, details that are not necessary for an understanding of the present invention or that might obscure other details may have been omitted.

[0010] It will be on Fig. Figure 1 refers to a control unit (1) designed to emulate gravitational acceleration in a vehicle. This control unit (1) communicates with the vehicle's braking system (2). The control unit will now be described in more detail.

[0011] According to one example, the control unit is a known electronic control unit (ECU). The ECU, or vehicle control unit (VCU), as known in the art, manages the operation of the electric motor (5), the battery, and the braking system. It monitors inputs from the brake pedal (4) and determines the required amount of regenerative braking or power input. The control unit ensures smooth transitions between regenerative braking and mechanical braking when necessary. According to the present disclosure, the control unit includes a central processing unit for executing control algorithms and real-time tasks. The control unit (1) further includes a memory, such as flash memory, which stores firmware and software, and RAM for the temporary storage of processing data.The control unit also includes an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), additional input / output (I / O) interfaces (such as CAN, LIN, Ethernet) and signal conditioning circuits.

[0012] The control unit also communicates with an electric motor (5) that provides propulsion in the vehicle; with various sensors and feedback systems installed in the vehicle, which include (among others) a pedal position sensor, inertial sensors, wheel speed sensors, ABS (anti-lock braking system), traction control system, and the like. For example, a braking system or brake control unit is integrated with the control unit to manage braking functionality.

[0013] The control unit is designed to receive a gradient reading from at least one sensor (3) that communicates with the control unit. According to one example, this sensor includes at least one inertial sensor, a gyroscope, an accelerometer, a wheel speed sensor, a camera, and the like. The calculation of a road gradient from an input from at least one of the aforementioned sensors is known.

[0014] According to the present disclosure, the control unit (1) is designed to determine a phantom gradient based on a user preference, to determine a gravitational acceleration corresponding to the phantom gradient, and to provide a torque to emulate the gravitational acceleration based on a brake pedal position and the gradient. According to the present disclosure, the brake pedal position is selected from a plurality of brake pedal positions, each brake pedal position corresponding to a unique phantom gradient. It is understood that the control unit (1) controls components such as an inverter to regulate the flow of electrical current to a motor (5) to emulate the gravitational acceleration.

[0015] The phantom gradient is a road incline that the driver perceives as comfortable while driving. It is selected according to user preference. For example, the user can choose their preferred acceleration profile, such as "relaxed," "sporty," etc., where the different acceleration profiles represent downhill driving at varying road gradients. The disclosed torque emulation function can be manually activated by the user via an interface. When activated, a phantom gradient (for example, an incline of approximately 10%) is set as the reference value for a more aggressive acceleration profile; a steeper gradient (approximately 20%) can be selected as the reference road incline. Conversely, a shallower gradient (approximately 7%) can be used as the reference gradient for a relaxed acceleration profile.It is understood that the control unit adjusts the phantom gradient according to the gradient (actual road incline) received from the at least one sensor. In other words, if the gradient (actual incline of the road where the vehicle is traveling) is greater than or equivalent to the user's preferred gradient, either this torque emulation functionality can be deactivated, or the phantom gradient can be adjusted accordingly.

[0016] According to the present disclosure, the functionality of emulating gravitational acceleration is deactivated if the resulting gradient is greater than a threshold gradient. According to another exemplary embodiment, if it is assumed that for a current phantom gradient preferred by the user, the required torque is 500 Nm, and the user applies the brake pedal at a position equivalent to 100 Nm, the overall emulation is adjusted from 500 Nm to 400 Nm, which in turn results in the deceleration of the vehicle desired by the driver.

[0017] In all cases, the vehicle's acceleration emulated by the control unit corresponds to the actual "acceleration due to gravity" experienced by the vehicle on the respective reference gradients. The user can select their desired acceleration profile using any interface provided by the vehicle manufacturer. According to the present disclosure, the control unit is designed to provide the braking function when the brake pedal position is beyond a threshold brake pedal position.

[0018] An example will illustrate this using... Fig. 3. The claimed features in more detail. According to Fig. Figure 3 represents the X-axis values ​​of the brake pedal input rod travel, and the Y-axis represents values ​​of the vehicle acceleration. To implement the present disclosure, the brake pedal is divided into two distinct ranges: an acceleration range and a deceleration range. The boundary between these ranges is referred to as the "virtual zero point." Releasing the pedal so that it is depressed less than the "virtual zero point" results in acceleration of the vehicle, while depressing the pedal beyond the "virtual zero point" results in deceleration of the vehicle. To maintain a constant speed (neither acceleration nor deceleration), the driver must keep the pedal at the "virtual zero point."Considering the challenge for drivers to position the pedal precisely at the virtual zero point, a "sailing range" was defined around it, within which the deceleration and acceleration effects are negligible.

[0019] According to one embodiment, assuming a stroke length of the brake pedal input rod is 20 mm, a "virtual zero point" is defined at "8 mm". A "sailing range" is defined "from 7 mm to 9 mm". According to the present disclosure and with reference to the example of Fig. 3. The vehicle accelerates if the driver releases the brake pedal to less than 7 mm. The degree of vehicle acceleration is directly proportional to the amount the brake pedal is released. For example, the vehicle acceleration when the brake pedal is released to 3 mm will exceed the acceleration when it is released to 5 mm. If the driver depresses the brake pedal more than 9 mm, the vehicle decelerates. The degree of vehicle deceleration is directly proportional to the amount the brake pedal is depressed. For example, the vehicle deceleration when the brake pedal is depressed 15 mm will exceed the deceleration when the brake pedal is depressed 10 mm. Within the range of 7 mm to 9 mm, the vehicle experiences negligible acceleration / deceleration.

[0020] Maximum vehicle acceleration is achieved when the driver fully releases the brake pedal. A road gradient that provides most drivers with a comfortable driving experience is referred to as a "phantom gradient," and the corresponding "acceleration due to gravity" at this gradient is defined as the standard value for maximum vehicle acceleration. Changes in acceleration, from maximum acceleration (at brake pedal position 0 mm) to acceleration at the "virtual zero" (brake pedal position at 8 mm), are calibrated to emulate the experience of driving downhill.

[0021] For example, a phantom gradient is created with a corresponding "acceleration due to gravity" of 2 m / s². 2 Assuming the brake pedal is fully released, the vehicle will accelerate by 2 m / s². 2If the brake pedal is positioned between 0 mm and 8 mm (virtual zero point), the vehicle's acceleration decreases accordingly, emulating the actual deceleration perceived on the phantom gradient.

[0022] It will be on Fig. 2 Referenced; this shows a flowchart for a method for emulating gravitational acceleration in a vehicle according to an embodiment of the present disclosure. It is understood that the method described herein is implemented by the control unit referred to above in connection with Fig.The procedure (100) comprises several steps. The first step (101) is to obtain a gradient, followed by step (102) of determining a phantom gradient based on a user preference. Step (103) is to determine a gravitational acceleration corresponding to the phantom gradient, and step (104) is to provide a torque to emulate this gravitational acceleration based on a brake pedal position and the gradient.

[0023] According to the present disclosure, the brake pedal position is selected from a plurality of brake pedal positions, each brake pedal position corresponding to a unique phantom gradient. A maximum gravitational acceleration corresponding to the specified phantom gradient is emulated when the brake pedal is in a released state. The functionality of emulating a gravitational acceleration is deactivated if the resulting gradient is greater than a threshold gradient.

[0024] The above description contains examples of the subject matter of the invention. It is naturally not possible to describe every conceivable combination of components or methodologies for the purpose of describing the claimed subject matter, but a person skilled in the art will recognize that many further combinations and permutations of the subject matter of the invention are possible. Accordingly, it is intended that the claimed subject matter includes all such changes, modifications, and variations that correspond to the basic idea of ​​the appended claims and fall within their scope of protection.

[0025] In particular, and with regard to the various functions performed by the components, devices, circuits, systems, and the like described above, it is intended that the terms (including any reference to a "means") used to describe such components, unless otherwise specified, correspond to any component that performs the specified function of the described component (e.g., a functional equivalent), even if it is not structurally equivalent to the disclosed structure, but which fulfills the function in the exemplary aspects of the claimed subject matter presented herein. In this context, it is also understood that the invention includes a system and a computer-readable medium containing instructions executable by a computer for carrying out the actions and / or events of the various methods of the claimed subject matter.

[0026] Furthermore, even if a particular feature of the invention has been disclosed in respect of only one of several implementations, such a feature may be combined with one or more other features of the other implementations if this is desirable and advantageous for any given or particular application. Moreover, where the terms "contains" and "containing" and variants thereof are used either in the detailed description or in the claims, it is intended that these terms be inclusive in a manner similar to the term "comprehensive".

Claims

[1] Control unit (1) designed to emulate gravitational acceleration in a vehicle, wherein the control unit (1) communicates with the braking system (2) of the vehicle, wherein the control unit (1) is designed to: - Obtaining a gradient from at least one sensor (3) that communicates with the control unit, characterized by that the control unit is designed for: - Determining a phantom gradient based on user preference, - Determining a gravitational acceleration corresponding to the phantom gradient, - Providing torque to emulate gravitational acceleration based on brake pedal position and gradient. [2] Control unit (2) according to claim 1, wherein the brake pedal position is selected from a plurality of brake pedal positions, each brake pedal position of these plurality of brake pedal positions corresponding to a unique phantom gradient. [3] Control unit (1) according to claim 1, wherein a maximum gravitational acceleration corresponding to the specified phantom gradient is emulated when the brake pedal is in a released state. [4] Control unit (1) according to claim 1, wherein the control unit is designed to provide the braking function when the brake pedal position is beyond a threshold brake pedal position. [5] Control unit according to claim 1, wherein the functionality of emulating a gravitational acceleration is deactivated when the obtained gradient is greater than a threshold gradient. [6] Method (100) for emulating gravitational acceleration in a vehicle, wherein the method is implemented by a control unit which communicates with the vehicle's braking system, wherein the method is characterized by: - Maintaining a gradient (101), - Determining a phantom gradient based on a user preference (102), - Determining a gravitational acceleration corresponding to the phantom gradient (103), - Providing a torque to emulate gravitational acceleration based on a brake pedal position and gradient (104). [7] Method (100) according to claim 6, wherein the brake pedal position is selected from a plurality of brake pedal positions, each brake pedal position of these plurality of brake pedal positions corresponding to a unique phantom gradient. [8] Method (100) according to claim 6, wherein a maximum gravitational acceleration corresponding to the specified phantom gradient is emulated when the brake pedal is in a released state. [9] Method (100) according to claim 6, wherein the functionality of emulating a gravitational acceleration is deactivated when the obtained gradient is greater than a threshold gradient.

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