EP3386829A1

EP3386829A1 - A vehicle drivability evaluation system and method

Info

Publication number: EP3386829A1
Application number: EP16828806.6A
Authority: EP
Inventors: Sinan EMIROGLU; Rasim Bozkurt; Murat ERGUL; Arda KAHRAMAN
Original assignee: Tofas Turk Otomobil Fabrikasi AS
Current assignee: Tofas Turk Otomobil Fabrikasi AS
Priority date: 2015-12-10
Filing date: 2016-12-01
Publication date: 2018-10-17
Also published as: TR201515862A2; WO2017099689A1

Abstract

The present invention relates to a vehicle drivability evaluation system and method (1), which will enable objective evaluation in the drivability tests conducted in the vehicle/product development stage, and which is basically characterized by at least one acceleration sensor (2) which enables to collect data of the acceleration occurring at departure, gear shifting or drifting maneuvers; at least one GPS speed sensor (3) which enables to record the data of the vehicle speed at gear shifting and departure maneuvers; at least one position sensor (4) which enables to collect the data of the pressure applied by the driver to the gas pedal or the clutch pedal at departure and gear shifting maneuvers; at least one fiber-optic sensor (5), which, upon being connected to the engine crank, enables to collect vehicle engine rpm (engine speed) data; at least one recording module (6) which is adapted to collect and record the data received from the acceleration sensor (2), GPS speed sensor (3), position sensor (4) and fiber-optic sensor (5); at least one electronic control unit (7) which is adapted to draw an evaluation conclusion by using the information in the recording module (6).

Description

A VEHICLE DRIVABILITY EVALUATION SYSTEM AND METHOD

Field of the Invention

The present invention relates to a vehicle drivability evaluation system and method (1), which enables to measure and record the vehicle's drivability values. Background of the Invention

In the drivability tests conducted in the vehicle/product development phase in automotive sector, drivers are employed in the systems which enable making objective evaluation.

Vehicle drivability tests depend on the subjective evaluations made by the drivers after many tests conducted by the drivers. There are open-ended points in subjective evaluation such as the facts that there are different points of view about what falls within the acceptance criteria, objective comparison of different driver evaluations is impossible, and verbal description of what the problem is and the expected behavior of the vehicle is difficult.

German patent document no. DE102013016488, an application in the state of the art, discloses a driver assistance system which is developed for motor vehicles and which allows collecting driving data. It is disclosed that an acceleration sensor which enables to obtain vehicle maneuver values and a GPS sensor used for determining the vehicle position are provided and vehicle departure data are collected in the said system. Furthermore, a data module wherein the obtained data are collected is disclosed. United States patent document no. US6598467, an application in the state of the art, describes an invention developed for analyzing operation performances of the motor vehicles, and discloses use of a course sensor for measuring the position of the gas pedal and an acceleration sensor for measuring vehicle performance.

United States patent document no. US6301957B 1, an application in the state of the art, discloses a system which is developed for collecting engine operation data in internal combustion engines. It is disclosed that the fiber-optic pressure sensor employed in the said system is used for collecting the values of the revolution of the crank shaft.

Chinese Utility Model no. CN201876922U, an application known in the state of the art, discloses a GPS speed sensor used for collecting vehicle speed data. The data obtained from the said system by the GPS speed sensor are recorded by a monitoring system.

United States Patent document no. US20040236473A1, an application known in the state of the art, discloses a data collection and measurement system developed for driving evaluation and vehicle performance. The sensor systems provided in the said system are used for evaluating vehicle drivability performance and driver's performance.

Problems Solved by the Invention

The objective of the present invention is to provide a vehicle drivability evaluation system and method, which will enable objective evaluation in the drivability tests conducted in the vehicle/product development stage. Another objective of the present invention is to provide a vehicle drivability evaluation system and method useful for providing a more effective vehicle driving. Detailed Description of the Invention

A vehicle drivability evaluation system developed to fulfill the objective of the present invention is illustrated in the accompanying figures, in which: Figure 1. is a schematic view of the vehicle drivability evaluation system. Figure 2. is a flowchart of the vehicle drivability evaluation system.

The components shown in the figures are given reference numbers as follows: 1. Vehicle drivability evaluation system

2. Acceleration sensor

3. GPS speed sensor

4. Position sensor

5. Fiber-optic sensor

6. Recording module

7. Electronic control unit

The vehicle drivability evaluation system and method (1), which enables to measure and evaluate the vehicle's drivability values, basically comprises

at least one acceleration sensor (2) which enables to collect data of the acceleration occurring at departure, gear shifting or drifting maneuvers, at least one GPS speed sensor (3) which enables to record the data of the vehicle speed at gear shifting and departure maneuvers, at least one position sensor (4) which enables to collect the data of the pressure applied by the driver to the gas pedal or the clutch pedal at departure and gear shifting maneuvers,

at least one fiber-optic sensor (5), which, upon being connected to the engine crank, enables to collect vehicle engine rpm (engine speed) data,

at least one recording module (6) which is adapted to collect and record the data received from the acceleration sensor (2), GPS speed sensor (3), position sensor (4) and fiber-optic sensor (5),

at least one electronic control unit (7) which is adapted to draw an evaluation conclusion by using the information in the recording module (6).

In the vehicle driv ability evaluation system and method (1) of the present invention; an acceleration sensor (2) which enables to collect data of the vehicle longitudinal acceleration at departure, shift gearing and rifting maneuvers, a GPS speed sensor (3) which enables to record the data of the vehicle speed at gear shifting and departure maneuvers, a position sensor (4) which enables to collect data of the pressure amount applied by the driver to the gas pedal or the clutch pedal at departure and gear shifting maneuvers, and a fiber-optic sensor (5) which, upon being connected to the engine crank, enables to collect the vehicle engine rpm data. There is provided a recording module (6) which is adapted to collect and record the data received from the acceleration sensor (2), GPS speed sensor (3), position sensor (4) and fiber-optic sensor (5). Additionally, an electronic control unit (7); which is adapted to control the acceleration sensor (2), GPS speed sensor (3), position sensor (4), fiber-optic sensor (5) and the module (6); is used.

The longitudinal acceleration sensor (2) enables to collect vehicle longitudinal acceleration data at departure, gear shifting and drifting maneuvers. Measuring the longitudinal acceleration occurring in the vehicle depending on the torque transferred from the engine during departure enables to obtain departure maneuver data. Furthermore, longitudinal acceleration signal is required for evaluation of the effect of the engine on the vehicle during gear shifting and at drifting maneuver of the vehicle with minimum engine torque. This physical acceleration directly affects the vehicle driving comfort. Therefore, the acceleration sensor (2) is positioned to a point near the vehicle's center of gravity for the measurement to be carried out.

The vehicle GPS speed sensor (3) enables to record the data of the vehicle speed at departure and gear shifting maneuvers. It enables to obtain information about the time the vehicle starts to move, especially the state of the clutch during departure. Furthermore, particularly the gear the vehicle is tested at the gear shifting maneuver is detected. A calculation channel is provided in the data collection software by using the engine rpm and vehicle speed for detection of the gear value.

The gas pedal/clutch pedal position measurement sensor (4) enables to collect the data regarding the amount of pressure applied by the driver on the gas pedal at departure and gear shifting maneuvers. The amount and speed of the pressure applied on the gas pedal/clutch pedal are used for obtaining information about the type of use of the vehicle. The position measurement sensor (4) enables to determine whether the vehicle is used in a normal, sportive or comfortable manner.

The fiber-optic sensor (5) is connected to the engine crank and enables to collect vehicle engine rpm data. This way, the effects caused by the driver on the vehicle at departure maneuver, gear shifting maneuver and in movement maneuvers with minimum engine torque are enabled to be determined. Depending on the engine torque map, the torque generated by the engine changes at every revolution. Prior to departure, the engine should generate sufficient torque for the driver to start the vehicle properly, and for this, the driver should raise the engine rpm to a sufficient value. Measurement of the engine rpm is one of the parameters required for classifying the departure as sportive or normal. Additionally it is used for evaluating the changes in the engine rpm during gear shifting and for examining the behavior in engine rpm occurring due to the effect of activation/deactivation of the air conditioner or electrical loads when the vehicle is moving at minimum engine torque. In the vehicle driv ability evaluation system and method (1) of the present invention; vehicle preparation, determining reliable drivers, determining ideal driver profile, data collection activities, determining evaluation criteria and physical data and the subjective SAE evaluations are carried out for the departure maneuver.

Determining reliable drivers; is conducting statistical studies in order to examine the influence of the driver individuals and the test dates on the driver evaluations. In determining reliable drivers, individuals exhibiting different behaviors based on the group are eliminated.

Ideal driver profile: Ideal driver profile is formed with the purpose of standardizing the input effects in order to eliminate the different reactions that will occur due to the difference of the effects of the driver on the vehicle. At departure maneuver of the drivers; Gas pedal usage percentage (%), Clutch release time (seconds), Departure rpm, and at Gear shifting maneuver, Gas pedal usage percentage (%), Clutch release time (seconds), Gear shifting revolution (rpm) values are recorded and stored in the electronic control unit (7). Ideal driver profile is formed by using the said values.

Departure maneuver; In order to carry out the vehicle preparation related to departure maneuver, several sub-criteria are evaluated and these are pumping, closing, stopping tendency and the first acceleration feeling. The departure maneuver is evaluated and graded by expert drivers. Furthermore, the obtained data are compared in the electronic control unit

(7)· Pumping movement can be defined as the shaking movements observed/experienced at the movement direction of the vehicle as of the moment when clutching occurs during departure maneuver. Data obtained from the longitudinal acceleration sensor (2) are used for evaluation of this movement. The data received from the acceleration sensor (2) by the help of the recording module (6) are processed by the electronic control unit (7). In the graphic formed by the obtained data, the peak points occurring at the moment of clutching during departure and following the first drop of the acceleration values are counted; and thus SAE score of the pumping movement is obtained. An XY distribution graphic is formed between the evaluation criteria derived from the data collected from the vehicle and the driver objective evaluations; and the correlation between the SAE scores and the evaluation criteria according to the formed meaningful groups is disclosed.

Closing movement can be defined as the sudden drop observed/felt in the engine rpm of the vehicle after the moment when clutching occurs during departure maneuver. Engine rpm data obtained from the fiber-optic sensor (5) are used for evaluation of this movement. The data received from the fiber-optic sensor (5) by the help of the recording module (6) are processed by the electronic control unit (7). An XY distribution graphic is formed between the data collected from the vehicle and the driver subjective evaluations; and the correlation between the SAE scores and the evaluation criteria according to the formed meaningful groups is disclosed.

Stopping tendency can be defined as the rpm decrease observed/felt when the engine rpm drops below or approaches to idling speed. Engine rpm data obtained from the fiber-optic sensor (5) are used for evaluation of this movement. Similarly, an XY distribution graphic is formed between the data collected from the vehicle and the driver subjective evaluations; and the correlation between the SAE scores and the evaluation criteria according to the formed meaningful groups is disclosed.

Acceleration movement can be defined as the mettle observed/felt from the starting moment of the departure motion until the first drop point of the acceleration in the direction of the vehicle's movement. Data obtained from the GPS speed sensor (3) are used for evaluation of this movement. The speed data here is obtained at the moment when acceleration first drops after clutching. Similarly, an XY distribution graphic is formed between the data collected from the vehicle and the driver subjective evaluations; and the correlation between the SAE scores and the evaluation criteria according to the formed meaningful groups is disclosed.

Data collection activities; During driving of the vehicle, the data obtained from the acceleration sensor (2), GPS speed sensor (3), position sensor (4) and fiber-optic sensor (5) are stored and processed on the recording module (6).

SAE evaluation and score calculation: Curve equations are calculated by combining the data collected by the recording module (6) and the drivers' physical evaluation data. For SAE score calculation; sub-criteria scores are defined as independent variables, and in order to determine the Global score equation which is the dependent variable, linear regression analysis is conducted. Linear regression analysis is conducted according to three different independent variable groups.

There are as follows:

Defining the subjective evaluations of the drivers as independent variables

- Placing the digital data received from the physical database into the equations obtained as a result of statistical studies, calculating objective SAE scores for each sub-criterion and defining these SAE scores as independent variable

Defining the data collected from the vehicle as independent variable Even though R²s of all three of the equations exhibit similarity with each other, it is decided that the most significant results are to be obtained with the data collected from the vehicle, and it is decided to use the third model for global SAE score calculation. The flow of the sub-criteria for departure maneuver and of the algorithm used in global SAE score calculation is as follows:

10- Performing departure maneuver

20- Recording the data received from the vehicle via the acceleration sensor (2), GPS speed sensor (3), position sensor (4) and fiber-optic sensor

(5) onto the recording module (6)

25- Reading the said data from the recording module (6)

30- Determining the start and end points of the vehicle movement

35- Conducting a pre-evaluation related to the movement according to the determined criteria, and if it does not comply with the criteria, repeating the movement

40- Determining the minimum values of the pumping data received from the acceleration sensor (2)

41- Filtering the data received from the acceleration sensor (2) 42- Determining the minimum and maximum points of the data received from the acceleration sensor (2)

43- Determining the first maximum peak point of the data received from the acceleration sensor (2) 44- Counting the minimum and maximum points occurring in the data received from the acceleration sensor (2)

45- Determining the difference between the points with maximum value and the points where it drops to minimum value (determining amplitude of the decrease) occurring in the data received from the acceleration sensor (2)

46- Determining the number of times the pumping process is repeated received from the acceleration sensor (2)

47- Determining the difference between the point with maximum value and the point where it drops to minimum value (this decrease value is the second peak following the first decrease peak of acceleration) occurring in the data received from the acceleration sensor (2) during pumping process

48- The electronic control unit (7) recording the obtained data,

50- Determining the minimum rpm values of the closing and stopping tendency obtained from the fiber-optic sensor (5) and determining the minimum values of the acceleration movement obtained from the GPS speed sensor (3)

51- Determining the time interval of the engine rpm data obtained from the fiber-optic sensor (5)

52- Determining the maximum and minimum value interval of the engine rpm data obtained from the fiber-optic sensor (5)

53- Determining the minimum peak points of the engine rpm data obtained from the fiber-optic sensor (5) in a determined time interval

54- Determining the difference between the points with maximum value and the points where it drops to minimum value occurring in the acceleration movement data obtained from the GPS speed sensor (3)

55- Determining the average acceleration movement from the acceleration movement data obtained from the GPS speed sensor (3) 56- The electronic control unit (7) recording the obtained data

Following the recording process, SAE score calculation is carried out as follows: a- SAE score of the pumping data are determined by calculating the data obtained by the electronic control unit (7) in line with the table given in Figure 2 b- if the answer for line "a" is yes, subjecting the parameters to a scoring determined according to special criteria c- if the answer for line "a" is no, applying to the model computed according to the statistical method d- determining pumping SAE score in line with Figure 2 e- if physical data which comply with the rules specifically defined for the closing, stopping tendency and acceleration feeling are produced, it is assigned to the related score f- if the answer for line "e" is yes, subjecting the parameters to a scoring determined according to special criteria g- if the answer for line "e" is no, applying to the model computed according to the statistical method h- Obtaining the raw SAE score for closing, stopping tendency and acceleration feeling i- Determining the final pumping SAE score according to the bandwidth or by rounding to integers j- Calculating departure maneuver global SAE score k- Calculating by placing the physical data collected from the vehicle during the test into the Global score calculation model

1- Obtaining the raw global SAE score for the departure maneuver m- Determining the final global SAE score according to the bandwidth or by rounding to integers The vehicle drivability evaluation system and method (1) provides the opportunity of objective evaluation in the drivability tests conducted in the vehicle/product development stage.

Claims

A vehicle drivability evaluation system and method (1), which provides the opportunity of objective evaluation in the drivability tests conducted in the vehicle/product development stage, basically characterized by

at least one acceleration sensor (2) which enables to collect data of the acceleration occurring at departure, gear shifting or drifting maneuvers, at least one GPS speed sensor (3) which enables to record the data of the vehicle speed at gear shifting and departure maneuvers,

at least one position sensor (4) which enables to collect the data of the pressure applied by the driver to the gas pedal or the clutch pedal at departure and gear shifting maneuvers,

at least one fiber-optic sensor (5), which, upon being connected to the engine crank, enables to collect vehicle engine rpm (engine speed) data, at least one recording module (6) which is adapted to collect and record the data received from the acceleration sensor (2), GPS speed sensor (3), position sensor (4) and fiber-optic sensor (5),

2. Vehicle drivability evaluation system and method (1) according to Claim 1, characterized by at least one acceleration sensor (2) which is positioned to a point near the vehicle's center of gravity.

3. Vehicle drivability evaluation system and method (1), which provides the opportunity of objective evaluation in the drivability tests conducted in the vehicle/product development stage, characterized by

performing departure maneuver (10) recording the data received from the vehicle via the acceleration sensor (2), GPS speed sensor (3), position sensor (4) and fiber-optic sensor (5) onto the recording module (6) (20) reading the said data from the recording module (6) (25) determining the start and end points of the vehicle movement (30) conducting a pre-evaluation related to the movement according to the determined criteria, and if it does not comply with the criteria, repeating the movement (35) determining the minimum values of the pumping data received from the acceleration sensor (2) (40) filtering the data received from the acceleration sensor (2) (41) determining the minimum and maximum points of the data received from the acceleration sensor (2) (42) determining the first maximum peak point of the data received from the acceleration sensor (2) (43) counting the minimum and maximum points occurring in the data received from the acceleration sensor (2) (44) determining the difference between the points with maximum value and the points where it drops to minimum value (determining amplitude of the decrease) occurring in the data received from the acceleration sensor (2) (45) determining the number of times the pumping process is repeated received from the acceleration sensor (2) (46) determining the difference between the point with maximum value and the point where it drops to minimum value (this decrease value is the second peak following the first decrease peak of acceleration) occurring in the data received from the acceleration sensor (2) during pumping process (47) the electronic control unit (7) recording the obtained data (48) determining the minimum rpm values of the closing and stopping tendency obtained from the fiber-optic sensor (5) and determining the minimum values of the acceleration movement obtained from the GPS speed sensor (3) (50)

determining the time interval of the engine rpm data obtained from the fiber-optic sensor (5) (51) determining the maximum and minimum value interval of the engine rpm data obtained from the fiber-optic sensor (5) (52) determining the minimum peak points of the engine rpm data obtained from the fiber-optic sensor (5) in a determined time interval (53) determining the difference between the points with maximum value and the points where it drops to minimum value occurring in the acceleration movement data obtained from the GPS speed sensor (3) (54) determining the average acceleration movement from the acceleration movement data obtained from the GPS speed sensor (3) (55) the electronic control unit (7) recording the obtained data (56).