ES2758185A1 - SYSTEM AND DEVICE INDICATOR OF DRIVING EFFICIENCY (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Driving efficiency indicator system and device that represents with a multi-colored LED sequence the duration, intensity and efficiency level of an acceleration or braking event. N levels of acceleration intensity are defined and each level is assigned a threshold and a color. As long as the acceleration intensity is below the minimum threshold, the LEDs in the sequence remain off and the central LED remains green. When the acceleration exceeds the minimum threshold, the first LED lights up with the color corresponding to the intensity level reached. As long as the acceleration exceeds the minimum threshold, LEDs will continue to light every Tdif milliseconds as illustrated in Figure 2 until the acceleration level is below the minimum threshold. At the end of the event the central LED shows the color corresponding to the average level of the intensities reached. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

DRIVING EFFICIENCY INDICATOR SYSTEM AND DEVICE

TECHNICAL SECTOR

The present invention relates to a system and device that provides vehicle drivers with indications of the efficiency of their driving style as an extension of the vehicle's dashboard, within the framework of so-called ecodriving systems . The system is intended for post-sale installation on buses, although it is also useful for trucks and commercial vehicle fleets, among others. In all applications, its objective is to allow drivers to know the level of efficiency of their driving and improve it in order to save fuel, reduce emissions in combustion vehicles or increase the range in electric vehicles, reduce maintenance costs and reduce accidentality.

BACKGROUND OF THE INVENTION

Numerous ecodriving systems are known that offer directions to drivers, such as the adaptation of the current gear and indication of changing gears, the state of the vehicle's speed in relation to its current consumption, the intensity of acceleration or braking, and others. However, there are far fewer suitable solutions in the objective sector of the invention, the purpose of which is the post-sale installation of a device in buses or vehicles that make frequent stops, with automatic gearboxes, where optimization is sought in each braking and where drivers are often overloaded with stimuli (relative to passenger care, relative to safety in a changing urban environment, and relative to maintaining a schedule), making ecodriving directions easily ignored or annoying.

In a patent analysis of the same class (IPC B60K35 / 00, arrangements on dashboard) as EP3486105 (Eco-drive assist apparatus, eco-drive assist information generating apparatus, eco-drive assist information calculation apparatus, eco-drive state display apparatus , eco-drive assist system, and eco-drive assist information calculation method), KR20130143330 20131122 (Method for providing ecological driving index) and others, as well as in studies (Tulusan, 2011, Eco-efficient feedback technologies) and (Wilfinger, 2009 , acceptance of future persuasive in-car interfaces towards a more economic driving behavior) we did not find solutions with the characteristics of the present invention that make it suitable for use in urban buses as well as in any other type of vehicle, it can be implemented at low cost , installed after sales, can be implanted independently from another system and offers intuitive, unobtrusive and complete indications on the level of efficiency ncia of driving.

EXPLANATION OF THE INVENTION

Concepts used:

• Acceleration = dynamic acceleration of the vehicle in its longitudinal axis

• Acceleration event = Positive acceleration (in the vehicle's direction of travel) whose measured value exceeds a pre-established minimum threshold, Threshold_a (1).

• Braking event = Negative acceleration whose measured absolute value exceeds a preset minimum threshold, Threshold_f (1)

• Events start when the absolute value of acceleration exceeds the minimum threshold and end when said value is less than said threshold minus a certain predefined hysteresis value.

The invention consists of a method and a system that allows instantaneous indications to the driver about the level of efficiency of his driving, based on the duration and intensity of acceleration and braking events, and a procedure to obtain a cumulative indicator of efficiency of driving based on these indications.

Explanation of the instant driving efficiency indication system

N levels of acceleration intensity are defined and each level is assigned an acceleration threshold (positive), Threshold_a (1), Threshold_a (2) ... Threshold_a (N), an acceleration (negative) threshold is assigned (braking), Threshold_f (1), Threshold_f (2) ... Threshold_f (N), and it is assigned a color, Color (1), Color (2) ... Color (N), where level 1 corresponds at the lowest measured absolute acceleration and level N at the highest absolute acceleration.

An integration time, Tdiff, is defined typically between 300 and 800ms.

The system consists of a main LED indicator light and a sequence of several LEDs configured for example as shown in Figure 1, with 11 LEDs arranged in a circular pattern and the main LED in the center.

As long as there is no event; that is, as long as the measured absolute acceleration is below the acceleration and braking thresholds corresponding to level 1, the main LED will show a color that indicates that driving is efficient (typically green) and the rest of the LEDs will be off.

When the measured absolute acceleration exceeds Threshold_a (N) or Threshold_f (N), the first LED in the sequence will light up with the color defined for the level, N, reached. Thus, if the measured acceleration exceeds Threshold_a (3) or Threshold_f (3), the LED will light up with Color (3).

If after the integration period, Tdiff, the measured absolute acceleration continues to exceed the value of Threshold_a (1) or Threshold_f (1), the second LED of the sequence will light up with the color corresponding to the level reached.

Similarly, as long as the measured absolute acceleration exceeds the minimum acceleration or braking threshold, LEDs will continue to light every Tdiff ms, showing on each LED the level reached in its integration period, color-coded associated with that level. Figure 2 shows an acceleration curve as a function of time exceeding several thresholds that generate an acceleration event whose duration is 5 Tdiff, and its representation on the LEDs.

The color of the central LED is updated in each new integration period to show the color corresponding to the average of the levels reached, Color (Level_media_event) t = n _ leds

^ level ( t )

where Level _ medium _ event = ——---------- where “n_leds” is the number of LEDs that are n _ leds

during the event (number of elapsed Tdiff periods) and “level (t)” have lit the level reached in period “t”; that is, if in the period "t" the measured acceleration has exceeded the Threshold_a (4) but not the Threshold_a (5) then level (t) = 4.

When the event ends, the indication is kept for a typical time of a few seconds so that the driver can see it. Thus, at the end of the event the driver will be able to see at a glance the duration of the event (number of LEDs lit), the intensities reached during the event (color of each LED) and the average assessment of driving efficiency for that event (color from the main LED)

Explanation of the procedure for obtaining a cumulative indicator of driving efficiency

For each intensity level of acceleration, i, a value of driving efficiency, VEC, is defined so that VEC (i) is equal to the value assigned to level i. For example VEC (4) = value that is assigned to an acceleration that is between thresholds 4 and 5. In the simplest case, VEC (1) = 1, VEC (2) = 2 ... VEC (N) is established. = N. The most suitable value will be established empirically so that the accumulated indicator is correlated with the consumption of the vehicle.

The indication of the accumulated driving efficiency over a period of time is calculated as follows:

m = n _ events VEC _ event _ max (m) - VEC _ event ( m)% VEC _ accumulated = 100% x ^

m = 1 VEC _ event _ max (m) - VEC _ event _ min (m)

Where for each event m:

t = n _ leds

VEC _ event = ^ VEC ( level ( t )) = sum of the VEC reached in each period of t ^{= 1}

integration, t, during an event.

t ⁼ n ^_ leds

VEC _ event _max = ^ VEC ( N ), and

t = n _ leds

VEC _ event _ min = ^ VEC (1),

t = 1

In summary, for the calculation of the indicator accumulated over a period of time, the VEC corresponding to the levels reached in each integration period in each event are added, and compared with the VEC corresponding to the maximum and minimum levels that could have been reached in each event.

The value of% VEC_accumulated is calculated separately for braking and acceleration obtaining two independent indicators, one for each type of event. This value is greater the higher the driving efficiency has been. If all the events were performed exceeding threshold 1 (event detection threshold) but not 2 (first inefficiency threshold) the result of% VEC_accumulated would be 100%.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1.- Shows an LED arrangement to generate the indications. LED 1 is the main LED and LEDs 2 to 12 are the sequence of LEDs that are activated every Tdiff ms while the acceleration exceeds the defined minimum threshold.

Figure 2.- Shows a curve of acceleration as a function of time and its representation with the instantaneous indicator. At the start of the event the acceleration exceeds the Threshold (1) and as a consequence the first LED with color (1) lights up. Tdiff ms after the acceleration is higher than the Threshold (3) and as a consequence the following LED lights up with the color (3). Similarly, the following LEDs light up until the event ends. At the end of the event, the number of LEDs lit represents the duration of the event, and its color the intensities reached by the acceleration at each moment (intensity profile).

Figure 5.- Shows the modules of a device that implements the invention as described in the PREFERRED EMBODIMENT OF THE INVENTION section.

PREFERRED EMBODIMENT OF THE INVENTION

The described method can be implemented with a device made up of the modules shown in Figure 3:

• (1) MCU - Microcontroller.

• (2) NVM - Non-volatile memory used to store parameters (thresholds, Tdiff, T_led_off) and to record the value of the indicators.

• (3) LED CONTROL - PMIC type LED control integrated circuits.

• (4) LEDs - Set of 16 tricolor LEDs configured as shown in Figure 3 • (5) Photosensor to measure the ambient light and adjust the lighting intensity of the LEDs accordingly.

• (6) Acoustic warning to warn the driver in case of very sudden acceleration or braking.

• (7) Power supply to allow direct connection of the module to vehicle power.

• (8) COM - Wireless communication module for data exchange with an external HOST, for example a Smartphone.

• (9) ODO IN - Input circuit for detecting vehicle odometer pulses.

The device is connected to the vehicle odometer sensor through the input circuit (8). This sensor generates a train of pulses whose frequency is proportional to the speed of the vehicle. The MCU detects the rising edges of each pulse and measures the time between edges. These times are stored in a matrix, T_odo_his.

Every T_period_odo ms the MCU compares the last value of T_odo_his with the measured value T_period_odo ms before, obtaining the difference. This difference multiplied by a factor, depending on the time and acceleration units used, allows obtaining the longitudinal dynamic acceleration of the vehicle.

If this acceleration is positive it is compared to the threshold, threshold_a (1). If it exceeds it, it is compared with threshold_a (2) and thus up to the maximum threshold established, threshold_a (5), determining the level reached, 1 to 5.

In a similar way, the acceleration is negative, comparing its absolute value with the thresholds threshold_f (1) to threshold_f (5) and determining the level reached, 1 to 5.

If any of the levels, i, is reached, the current LED lights up with the color associated with the level, color (i) and the color of the main LED, LED 1 in Figure 1, is updated.

The current LED will be the first LED in the sequence, or LED 2 in figure 1, if the event has just started, or LED 3 in the same figure in the event that an integration period has elapsed, or the LED 4 in the event that two integration periods have elapsed, etc.

When the acceleration measured in an integration period falls below the minimum threshold, no new LEDs will light, but the current LEDs will remain on for a period of time, T_led_off, so that the driver can see the result of the event.

Once T_led_off has elapsed without detecting an acceleration that exceeds the minimum threshold, the LEDs go out and the corresponding VECs are calculated:

• If the event has been generated by a positive acceleration, the VEC corresponding to accelerations are accumulated and the accumulated indicator of acceleration efficiency% aVEC_accumulated is updated as follows:

o aVEC_acum = aVEC_acum + VEC_evento

OR aVEC_min_acum = aVEC_min_acum VEC_evento_min

o aVEC_max_acum = aVEC_max_acum VEC_evento_max

_{or AveC% = 100% x accumulated} AVEC _ max_ accum - AVEC _ accum

Avec _ max_ accum - AVEC _ min_ accum

• If the event was generated by a negative acceleration, the VEC corresponding to braking are accumulated and the accumulated indicator of braking efficiency% fVEC_accumulated is updated as follows:

o fVEC_acum = fVEC_acum + VEC_evento

o fVEC_min_acum = fVEC_min_acum VEC_evento_min

o fVEC_max_acum = fVEC_max_acum VEC_evento_max

om % fVEC _ accumulate , ad ^j o = 100% x fVEC max accum - fVEC accum

_ fVEC max_ accum - min_ fVEC _ accum

The device registers the accumulated% VEC and at the end of driving downloads it to a HOST, typically a Smartphone, through a wireless communications module, WiFi or Bluetooth. An application in the HOST allows the driver to be identified and the vehicle located to associate the downloaded driving data with a driver and a route and obtain driving efficiency reports for each driver on each route.

Claims (4)

1.- Indicator device of the efficiency of the driving style that represents in real time the intensity and duration of inefficient braking or acceleration events in a vehicle; Composed of a set of multicolour light indicators arranged sequentially and a process module characterized by calculating the longitudinal dynamic acceleration of the vehicle and comparing its absolute value with various acceleration thresholds, each associated with a color, so that if the absolute value of vehicle acceleration exceeds the minimum threshold for a time interval, Tdiff, the first indicator turns on and indicators continue to light sequentially with a time lapse Tdiff between one indicator and the next as long as the acceleration continues to exceed the minimum threshold, turning on each indicator with the color associated with the maximum threshold exceeded during the previous Tdfiff interval, so that at the end of the event, once the acceleration falls below the minimum threshold, the number of indicators lit, N, represents the duration of the event ( NxTdiff) and its color represents the acceleration intensities reached in each interval or time, Tdiff, during the event (Fig. 4). 2.- Driving style efficiency indicator device according to claim 1, which includes an additional indicator light whose color represents the overall efficiency of the acceleration or braking event, which is determined by averaging the intensities reached in each interval (adding the intensities reached in each interval and dividing the result by the number of intervals that the event lasted, NxTdiff) and comparing the result with the acceleration thresholds, with the color set being the one associated with the maximum threshold exceeded by said result. 3.- Procedure to determine the efficiency of a driving style during a period of time in which multiple driving events occur, a driving event being any acceleration or braking whose acceleration exceeds in absolute value a predefined minimum acceleration threshold, characterizing said procedure because: • in each driving event you get three values, Vmejor, Vevento and Vpeor, • these values are obtained in a process as defined in claim 1 where each event is divided into a series of time intervals of duration Tdiff, associating to each acceleration threshold a value, Vevent_diff (Threshold (n)) so that : i = n _ Tdiff V_best = ^ Vbest _ diff , i = 1 i = n _ Tdiff Event = ^ Event _ diff (i) and i = 1 i = n _ Tdiff Vpeor = ^ Vpeor _ diff , i = 1 where Event_diff (i) = Event_diff (Threshold (i)) is the value associated with the maximum threshold exceeded in interval i of the event, and the values Vmejor_diff and Vpeor_diff are empirically defined from the drivers with more and less efficient driving styles respectively, being the extreme values of a scale in which the intermediate values are defined, Vevento_diff (Threshold (i)), which are associated at every threshold; • The three values obtained in each event are accumulated to obtain: m = n _ events V_best_accumulated = ^ Vbest (m), m = 1 m = n _ events Accumulated event = ^ Event ( m) and m = 1 m = n _events Accumulated_pear = ^ Vpeor (m), m = 1 where Vmejor (m), Vevento (m) and Vpeor (m) are the values of Vmejor, Vevento and Vpeor obtained in event m respectively; • Finally, a global value of driving efficiency during the period is calculated by comparing Cumulative Vento with the extreme values of the comparison scale, V_best_accumulated and Vpeor_accumulated 4.- Procedure according to claim 3 in which the scale of values associated with the thresholds is linear and V_best_accumulated is the minimum value of the scale and Vpeor_accumulated is the maximum value of the scale, consisting of calculating the global value of the efficiency of the driving during a period as a percentage between the minimum and maximum value of the scales according to the following equation: „ ^ R. . . Accumulated Weight - Accumulated Veventum _{% Efficiency = 100% x} Vpeor _ accumulated - Vmejor _ accumulated