Apparatus and method for determining mounting state of electronic control unit of electronically controlled suspension system

An apparatus and a method for determining a mounting state of an electronic control unit (ECU) of an electronic controlled suspension (ECS) system can determine either a normal mounting state or a mounting failure of the ECU of the ECS system. The apparatus for determining the mounting state of the ECU includes: a signal processor receiving a damper velocity of each damper; an integrator calculating an integral of the damper velocity by integrating the damper velocity of each damper received by the signal processor per unit time; a comparator comparing the integral of the damper velocity calculated by the integrator with an actual stroke of each damper; and an index output unit outputting a mounting state of the ECU in the form of an index according to comparison results of the comparator.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims under 35 U.S.C. § 119(a) the benefit of Korean Patent Application No. 10-2016-0038511, filed on Mar. 30, 2016 in the Korean Intellectual Property Office, the entire contents of which are incorporated by reference herein.

BACKGROUND

(a) Technical Field

The present invention relates to a method for determining a mounting state of an electronic control unit of an electronic controlled suspension system that can determine either a normal mounting state or a mounting failure of the electronic control unit of the electronic controlled suspension system.

(b) Description of the Related Art

In general, suspension systems for vehicles have used various types of springs, such as leaf springs, coil springs, torsion bars, rubber springs, air springs and the like, as well as shock absorbers, but with the development of electronic technology, an electronic controlled suspension (ECS) system has been designed to control vehicle stability so as to avoid an unstable vehicle state, due to factors such as vibrations of a vehicle on a road surface or rolling of the vehicle body while turning.

When vehicle steering or vehicle behavior exceeds certain limits, a vehicle operator may face overturning of the vehicle or other unpredictable risks if the vehicle pulls to one side due to load difference or steering loss. However, a vehicle with an ECS system may secure vehicle stability while turning, braking, and driving by maintaining vertical load on individual tire treads at an appropriate level while driving on an uneven road surface, and may provide passengers with a greater degree of ride comfort and improved vehicle handling by effectively isolating irregular pressure on the road surface occurring during driving.

Such an ECS system includes an electronic control unit (ECU) controlling a plurality of dampers provided on respective wheels of the vehicle, and the ECU typically has a vertical acceleration sensor in the interior thereof so as to sense acceleration in a vertical direction.

Meanwhile, when the ECU of the ECS system is mounted abnormally in the vehicle, errors may occur in calculating the velocity of the dampers due to abnormalities in sensing values sensed by the vertical acceleration sensor, and thus, suspension control may not be performed normally.

SUMMARY

An aspect of the present invention provides a method for determining a mounting state of an electronic control unit (ECU) of an electronic controlled suspension (ECS) system that can effectively determine the normal mounting state or mounting failure of the ECU of the ECS system.

According to an aspect of the present invention, an apparatus for determining a mounting state of an ECU of an ECS system including a plurality of dampers individually provided on respective wheels of a vehicle, a wheel acceleration sensor provided on each front wheel of the vehicle, and the ECU having a vertical acceleration sensor built in an interior thereof and controlling each of the dampers, the apparatus may include: a signal processor receiving a damper velocity of each of the dampers; an integrator calculating an integral of the damper velocity by integrating the damper velocity of each of the dampers received by the signal processor per unit time; a comparator comparing the integral of the damper velocity calculated by the integrator with an actual stroke of each of the dampers; and an index output unit outputting a mounting state of the ECU as an index according to comparison results of the comparator.

When the comparator determines that an integral of the damper velocity of at least one of the dampers is greater than an actual stroke of the corresponding damper, the index output unit may output an abnormal mounting index of the ECU.

When the abnormal mounting index of the ECU is output, the ECS system may enter a failsafe mode.

When the comparator determines that an integral of the damper velocity is less than or equal to the actual stroke of at least one of the dampers, the index output unit may output a normal mounting index of the ECU.

According to another aspect of the present invention, a method for determining a mounting state of an ECU of an ECS system including a plurality of dampers individually provided on respective wheels of a vehicle, a wheel acceleration sensor provided on each front wheel of the vehicle, and the ECU having a vertical acceleration sensor built in an interior thereof and controlling each of the dampers, the method may include steps of: calculating, by a signal processor of the ECU, a damper velocity of each of the dampers; calculating, by an integrator of the ECU, an integral of the damper velocity by integrating the damper velocity of each of the dampers per unit time; and comparing, by a comparator of the ECU, the integral of the damper velocity with an actual stroke of each of the dampers to determine a mounting state of the ECU.

The damper velocity of each of the dampers may be calculated by converting a measured value of the wheel acceleration sensor and a measured value of the vertical acceleration sensor into acceleration values of the respective wheels and integrating a difference between the converted measured values of the wheel acceleration sensor and the vertical acceleration sensor.

When an integral of the damper velocity of at least one of the dampers among the plurality of dampers is greater than an actual stroke of the corresponding damper, it may be determined that the ECU is mounted abnormally.

When the ECU is mounted abnormally, the ECS system may enter a failsafe mode.

When the integral of the damper velocity is less than or equal to the actual stroke of the corresponding damper, it may be determined that the ECU is mounted normally.

A non-transitory computer readable medium containing program instructions executed by a processor can include: program instructions that calculate a damper velocity of each of a plurality of dampers; program instructions that calculate an integral of the damper velocity by integrating the damper velocity of each of the dampers per unit time; and program instructions that compare the integral of the damper velocity with an actual stroke of each of the dampers to determine a mounting state of an electronic control unit (ECU) of an electronic controlled suspension (ECS) system.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Terms used for describing the present inventive concept have been defined in consideration of the functions of elements, and may be altered in accordance with the intention of a user or an operator, in view of practice, or the like. Therefore, the terms should be defined on the basis of the entirety of this specification.

With reference toFIG. 1, an electronic controlled suspension (ECS) system1includes a plurality of dampers2individually provided on respective wheels5of a vehicle, a wheel acceleration sensor3provided on each front wheel of the vehicle, and an electronic control unit (ECU)4controlling each of the dampers2.

The ECU4may have a vertical acceleration sensor6built in the interior thereof, and may calculate damper velocity by converting a measured value of the wheel acceleration sensor3and a measured value of the vertical acceleration sensor6into accelerations values of the respective wheels and integrating a difference between the converted measured values of the wheel acceleration sensor3and the vertical acceleration sensor6. Here, damper velocity refers to a velocity at which the damper2of each wheel5moves in a constant stroke (extension movement). The ECU4may control each individual damper2by using the calculated damper velocity of each damper2.

With reference toFIG. 2, an apparatus for determining a mounting state of an ECU of an ECS system, according to exemplary embodiments of the present invention, includes a signal processor11receiving a damper velocity of each damper2, an integrator12calculating an integral of the damper velocity, a comparator13comparing the integral of the damper velocity calculated by the integrator12with an actual stroke (StrokeTHD) of the corresponding damper, and an index output unit15outputting a mounting state of the ECU4in the form of an index according to comparison results of the comparator13.

The signal processor11may be configured to individually receive a damper velocity of a damper provided on a front left wheel (FL), a damper velocity of a damper provided on a front right wheel (FR), a damper velocity of a damper provided on a rear left wheel (RL), and a damper velocity of a damper provided on a rear right wheel (RR). In addition, the signal processor11may perform appropriate filtering such that the calculation of the integrator12can be performed efficiently.

The integrator12may calculate an integral of a damper velocity by integrating the damper velocity of each damper received by the signal processor11per unit time.

The comparator13may compare the integral of the damper velocity received from the integrator12with an actual stroke (StrokeTHD) of each damper2.

The index output unit15may output a mounting state of the ECU4in the form of an index according to comparison results of the comparator13.

When the comparator13determines that an integral of a damper velocity of at least one damper among the plurality of dampers is greater than an actual stroke (StrokeTHD) of the corresponding damper, the index output unit15may output an “abnormal mounting index” indicating a state in which the ECU4is mounted abnormally. When the “abnormal mounting index” of the ECU4is output, the ECS system1enters a failsafe mode.

When the comparator13determines that the integral of the damper velocity of each damper2is less than or equal to the actual stroke (StrokeTHD) of the corresponding damper2, the index output unit15may output a “normal mounting index” indicating a state in which the ECU4is mounted normally, and the ECU4may operate normally.

The signal processor11, the integrator12, the comparator13, and the index output unit15may be embodied in a controller of the ECU4.

FIG. 3is a flowchart illustrating a method for determining a mounting state of an ECU of an ECS system, according to exemplary embodiments of the present invention.

With reference toFIG. 3, the method for determining a mounting state of an ECU of an ECS system, according to exemplary embodiments of the present invention, includes a damper velocity calculation S1, an integral calculation S2, and a comparison operation S3.

In the damper velocity calculation S1, a damper velocity of each individual damper2provided on respective wheels5may be calculated by converting a measured value of the wheel acceleration sensor3and a measured value of the vertical acceleration sensor6into accelerations values of the respective wheels and integrating a difference between the converted measured values of the wheel acceleration sensor3and the vertical acceleration sensor6.

In the integral calculation S2, an integral (Strokecal) of the damper velocity may be calculated by integrating the damper velocity of each individual damper2per unit time.

In the comparison operation S3, the integral (Strokecal) of the damper velocity may be compared with an actual stroke of the corresponding damper2to determine a mounting state of the ECU4.

In the comparison operation S3, when an integral (an absolute value) of a damper velocity of at least one damper2among the plurality of dampers2is greater than an actual stroke (StrokeTHD) of the corresponding damper2, it is determined in operation S4that the ECU4is mounted abnormally. When it is determined that the ECU4is mounted abnormally, the ECS system1may enter a failsafe mode in operation S5.

In the comparison operation S3, when the integral (Strokecal) of the damper velocity is less than or equal to the actual stroke (StrokeTHD) of the corresponding damper2, it is determined in operation S6that the ECU4is mounted normally, and the ECS system may operate normally in operation S7.

As set forth above, by determining the normal or abnormal mounting state of the ECU of the ECS system through the comparison of the integral of the damper velocity with the actual stroke of the damper, the normal mounting state or mounting failure of the ECU of the ECS system can effectively be determined.