CN104748974B - Based on the vehicle collision detection method that MEMS sensor is not horizontally mounted - Google Patents

Abstract

A kind of vehicle collision detection method not being horizontally mounted based on MEMS sensor, is comprised the following steps：S1., MEMS sensor is installed on vehicle, and calculates Installation posture angle；S2. the output of the accelerometer of MEMS sensor is decomposed into by the upward speed increment in vehicle forward direction, lateral direction of car and vehicle day according to Installation posture angle；S3. the speed increment after decomposition is converted into acceleration；S4. collision detection is carried out to vehicle forward direction and/or laterally.The present invention realizes the effective detection to vehicle collision.

Description

Based on the vehicle collision detection method that MEMS sensor is not horizontally mounted

Technical field

The present invention relates to a kind of collision checking method, more particularly to a kind of vehicle not being horizontally mounted based on MEMS sensor Collision checking method.

Background technology

Increasing with vehicle, traffic accident also increasingly takes place frequently, so the collision of vehicle is timely and effectively detected, The injures and deaths of traffic accident can effectively be reduced.In order to realize the detection to vehicle collision, general to use OBD mobile units, this sets It is standby to include mems accelerometer and gyroscope, but due to being limited by aspects such as installation site sizes, the installation of the equipment With larger randomness, it is impossible to which guarantee is installed horizontally.

The content of the invention

In order to solve the above-mentioned technical problem, touched based on the vehicle that MEMS sensor is not horizontally mounted the invention provides a kind of Hit detection method, it is possible to achieve to the effective detection of vehicle collision.The technical scheme is that：One kind is based on MEMS sensor The vehicle collision detection method not being horizontally mounted, comprises the following steps：

S1., MEMS sensor is installed on vehicle, and calculates Installation posture angle；

S2. the output of the accelerometer of MEMS sensor is decomposed into by vehicle forward direction, vehicle according to Installation posture angle Transverse direction and the upward speed increment of vehicle day；

S3. the speed increment after decomposition is converted into acceleration；

S4. collision detection is carried out to vehicle forward direction and/or laterally.

Used as the further supplement of technical scheme, Installation posture angle calculation procedure is as follows：

(1) calculation error compensation

Make N_a=(N_ax,N_ay,N_az)^T, then

Wherein Na is the raw velocity increment signal amount output of three axles of accelerometer, N_ax,N_ay,N_azIt is respectively Chinese herbaceous peony Enter direction, the upward speed increment of transverse direction and day,It is the nominal amount of accelerometer；

(2) the specific force increment δ w after calculation error compensation^b：

δ T are systematic sampling time interval, k₀Be accelerometer each axle zero partially, Ea is the alignment error of accelerometer Matrix；

(3) specific force incremental integration is calculated

Δw^b ₌Σδw^b

(4) normalize

Wherein, g_α(α=x, y, z) is car direction of advance, transverse direction and day normalized result upwards, and Δ w is intermediate variable Output；

(5) Installation posture angle is calculated

Order：Roll angle and the angle of pitch then in Installation posture angle is calculated such as Under：θ=arcsinT₃₂；Wherein：θ is roll angle, and γ is the angle of pitch.

It is vehicle forward direction, car by the output quantity decomposition method of accelerometer as the further supplement of technical scheme The method of transverse direction and the upward speed increment of vehicle day is：The output quantity of accelerometer is decomposed using following formula, is obtained Three speed increments in direction；

Wherein, g_level_x, g_level_y, g_level_z are in vehicle forward direction, lateral direction of car and car after decomposing The upward speed increment in day, wb_x, wb_y, wb_z are compensation specific force increments in vehicle forward direction, lateral direction of car and vehicle Its upward decomposition.

As the further supplement of technical scheme, it is by the method that the speed increment after decomposition is converted to acceleration：Use Speed increment is converted to acceleration by following formula；

G_x=g_level_x/ δ T/g₀；

G_y=g_level_y/ δ T/g₀；

Wherein, g₀It is local gravitational acceleration, g_x and g_y represents the acceleration of vehicle forward direction and lateral direction of car respectively Spend, unit is：g.

Used as the further supplement of technical scheme, the method for vehicle forward direction collision detection is：Often take ten groups of acceleration Value calculates a variance, and adds round-robin queue, until finding there is one group of variance ratio previous group and later group of acceleration magnitude all During more than a certain multiple, it is judged to there occurs collision in vehicle forward direction.

Used as the further supplement of technical scheme, the method for lateral direction of car collision detection is：Often take ten groups of acceleration magnitude meters A variance is calculated, and adds round-robin queue, until variance ratio previous group and later group that discovery has one group of acceleration magnitude are both greater than During a certain multiple, it is judged to there occurs collision in the lateral direction of the vehicle.

The invention further relates to a kind of collision detecting apparatus for vehicle not being horizontally mounted based on MEMS sensor, including：

Sensor is installed and Installation posture angle computing device, for installing MEMS sensor in vehicle, and calculates installation Attitude angle；

The output decomposer of accelerometer, for according to Installation posture angle by the output of the accelerometer of MEMS sensor It is decomposed into the upward speed increment in vehicle forward direction, lateral direction of car and vehicle day；

Acceleration conversion equipment, for the speed increment after decomposition to be converted into acceleration；

Collision detecting device, for carrying out collision detection to vehicle forward direction and/or transverse direction.

Beneficial effect：Invention herein on the premise of MEMS is not horizontally mounted, by calculating not horizontal (Installation posture Angle) and the method that carries out Coordinate Conversion, MEMS coordinate systems are converted into vehicle forward direction, transverse direction, day to three-dimensional system of coordinate, Change to realize the detection to vehicle collision by real-time detection vehicle forward direction, transverse acceleration.The present invention can be quick Effective identification car two is collided, and the regulation of multiple is differed according to the variance for comparing, and it is different that the present invention realizes identification The vehicle collision of sensitivity.

Brief description of the drawings

Fig. 1 is schematic flow sheet of the invention.

Specific embodiment

Embodiment：

A kind of vehicle collision detection method not being horizontally mounted based on MEMS sensor, is comprised the following steps：

S1., MEMS sensor is installed on vehicle, and calculates Installation posture angle；

Installation posture angle calculation procedure is as follows：

(1) calculation error compensation

Make N_a=(N_ax,N_ay,N_az)^T, then

Wherein Na is the raw velocity increment signal amount output of three axles of accelerometer, N_ax,N_ay,N_azIt is respectively Chinese herbaceous peony Enter direction, the upward speed increment of transverse direction and day,It is the nominal amount of accelerometer；

(2) the specific force increment δ w after calculation error compensation^b：

δ T are systematic sampling time interval, k₀Be accelerometer each axle zero partially, Ea is the alignment error of accelerometer Matrix；

(3) specific force incremental integration is calculated

Δw^b=Σ δ w^b

(4) normalize

Wherein, g_α(α=x, y, z) is car direction of advance, transverse direction and day normalized result upwards, and Δ w is intermediate variable Output；

(5) Installation posture angle is calculated

Order：Roll angle and the angle of pitch then in Installation posture angle is calculated such as Under：θ=arcsinT₃₂；Wherein：θ is roll angle, and γ is the angle of pitch.

S2. the output of the accelerometer of MEMS sensor is decomposed into by vehicle forward direction, vehicle according to Installation posture angle Transverse direction and the upward speed increment of vehicle day；

It is that vehicle forward direction, lateral direction of car and vehicle day upward speed increase by the output quantity decomposition method of accelerometer The method of amount is：The output quantity of accelerometer is decomposed using following formula, obtains three speed increments in direction；

Wherein, g_level_x, g_level_y, g_level_z are in vehicle forward direction, lateral direction of car and car after decomposing The upward speed increment in day, wb_x, wb_y, wb_z are compensation specific force increments in vehicle forward direction, lateral direction of car and vehicle Its upward decomposition.

S3. the speed increment after decomposition is converted into acceleration；

It is by the method that the speed increment after decomposition is converted to acceleration：Speed increment is converted into acceleration using following formula Degree；

G_x=g_level_x/ δ T/g₀；

G_y=g_level_y/ δ T/g₀；

Wherein, g₀It is local gravitational acceleration, g_x and g_y represents the acceleration of vehicle forward direction and lateral direction of car respectively Spend, unit is：g.

S4. collision detection is carried out to vehicle forward direction and/or laterally；

The method of vehicle forward direction collision detection is：Often take ten groups of acceleration magnitudes and calculate a variance, and add circulation Queue, when variance ratio previous group and later group that discovery has one group of acceleration magnitude are both greater than a certain multiple, is judged in car Direction of advance there occurs collision, as follows：

varx1>factor*varx2；

varx1>factor*varx0；

The method of lateral direction of car collision detection is：Often take ten groups of acceleration magnitudes and calculate a variance, and add round-robin queue, When variance ratio previous group and later group that discovery has one group of acceleration magnitude are both greater than a certain multiple, it is judged in lateral direction of car On there occurs collision, it is as follows：

vary1>factor*vary2；

vary1>factor*vary0；

Wherein, vary0, vary1, vary2 represent three groups of adjacent variance yields of acceleration, and factor is adjustable system Number, the smaller collision recognition of coefficient is sensitiveer, and the size of the coefficient can be adjusted according to actual conditions.

The invention further relates to a kind of collision detecting apparatus for vehicle not being horizontally mounted based on MEMS sensor, including：

Sensor is installed and Installation posture angle computing device, for installing MEMS sensor in vehicle, and calculates installation Attitude angle；

The output decomposer of accelerometer, for according to Installation posture angle by the output of the accelerometer of MEMS sensor It is decomposed into the upward speed increment in vehicle forward direction, lateral direction of car and vehicle day；

Acceleration conversion equipment, for the speed increment after decomposition to be converted into acceleration；

Collision detecting device, for carrying out collision detection to vehicle forward direction and/or transverse direction.

Claims (6)

1. a kind of vehicle collision detection method not being horizontally mounted based on MEMS sensor, it is characterised in that：Comprise the following steps：

S1., MEMS sensor is installed on vehicle, and calculates Installation posture angle；

S2. the output of the accelerometer of MEMS sensor is decomposed into by vehicle forward direction, lateral direction of car according to Installation posture angle And the upward speed increment of vehicle day；

S3. the speed increment after decomposition is converted into acceleration；

S4. collision detection is carried out to vehicle forward direction and/or laterally；

Installation posture angle calculation procedure is as follows：

(1) calculation error compensation

Make N_a=(N_ax,N_ay,N_az)^T, then

Wherein Na is the raw velocity increment signal amount output of three axles of accelerometer, N_ax,N_ay,N_azIt is respectively the Chinese herbaceous peony side of entering To, the upward speed increment of transverse direction and day,It is the nominal amount of accelerometer；

(2) the specific force increment δ w after calculation error compensation^b：

${\mathrm{\δw}}^b=Ea({\mathrm{\δw}}_1^b-k_0\mathrm{\δ}T)$

δ T are systematic sampling time interval, k₀Be accelerometer each axle zero partially, Ea is the alignment error matrix of accelerometer；

(3) specific force incremental integration is calculated

Δw^b=∑ δ w^b

(4) normalize

$\mathrm{\Δ}w=\sqrt{{\mathrm{\Δw}}_x^{b^2}+{\mathrm{\Δw}}_y^{b^2}+{\mathrm{\Δw}}_z^{b^2}}$

$g_{\mathrm{\α}}^b=\frac{{\mathrm{\Δw}}_{\mathrm{\α}}^b}{\mathrm{\Δ}w}$

Wherein, g_α(α=x, y, z) is car direction of advance, transverse direction and day normalized result upwards, and Δ w is intermediate variable output；

(5) Installation posture angle is calculated

Order：Then the roll angle and the angle of pitch in Installation posture angle are calculated as follows：θ= arcsinT₃₂；Wherein：θ is roll angle, and γ is the angle of pitch.

It is 2. as claimed in claim 1 to be based on the vehicle collision detection method that MEMS sensor is not horizontally mounted, it is characterised in that By the method that the output quantity decomposition method of accelerometer is the upward speed increment in vehicle forward direction, lateral direction of car and vehicle day For：The output quantity of accelerometer is decomposed using following formula, obtains three speed increments in direction；

${\left|\begin{array}{c}g\_level\_x\\ g\_level\_y\\ g\_level\_z\end{array}\right|}^T={\left|\begin{array}{c}wb\_x\\ wb\_y\\ wb\_z\end{array}\right|}^T*\left|\begin{array}{ccc}1& 0& 0\\ 0& cos\mathrm{\γ}& sin\mathrm{\γ}\\ 0& -\sin \mathrm{\γ}& cos\mathrm{\γ}\end{array}\right|*\left|\begin{array}{ccc}cos\mathrm{\θ}& 0& -sin\mathrm{\θ}\\ 0& 1& 0\\ sin\mathrm{\θ}& 0& \cos \mathrm{\θ}\end{array}\right|$

Wherein, g_level_x, g_level_y, g_level_z are in vehicle forward direction, lateral direction of car and vehicle day after decomposing Upward speed increment, wb_x, wb_y, wb_z are that the compensation specific force increment in claim 1 is horizontal in vehicle forward direction, vehicle To and day upward decomposition of vehicle.

It is 3. as claimed in claim 2 to be based on the vehicle collision detection method that MEMS sensor is not horizontally mounted, it is characterised in that It is by the method that the speed increment after decomposition is converted to acceleration：Speed increment is converted into acceleration using following formula；

G_x=g_level_x/ δ T/g₀；

G_y=g_level_y/ δ T/g₀；

Wherein, g₀It is local gravitational acceleration, g_x and g_y represents the acceleration of vehicle forward direction and lateral direction of car respectively, it is single Position is：g.

It is 4. as claimed in claim 3 to be based on the vehicle collision detection method that MEMS sensor is not horizontally mounted, it is characterised in that The method of vehicle forward direction collision detection is：Often take ten groups of acceleration magnitudes and calculate a variance, and add round-robin queue, until It was found that when the variance ratio previous group and later group that have one group of acceleration magnitude are both greater than a certain multiple, being judged in vehicle forward direction There occurs collision.

It is 5. as claimed in claim 4 to be based on the vehicle collision detection method that MEMS sensor is not horizontally mounted, it is characterised in that The method of lateral direction of car collision detection is：Often take ten groups of acceleration magnitudes and calculate a variance, and add round-robin queue, until finding When the variance ratio previous group and later group for having one group of acceleration magnitude are both greater than a certain multiple, it is judged to there occurs in the lateral direction of the vehicle Collision.

6. a kind of perform claim requires the vehicle collision detection side not being horizontally mounted based on MEMS sensor described in any one of 1-5 The device of method, it is characterised in that：Including：

Sensor is installed and Installation posture angle computing device, for installing MEMS sensor in vehicle, and calculates Installation posture Angle；

The output decomposer of accelerometer, for being decomposed the output of the accelerometer of MEMS sensor according to Installation posture angle It is the upward speed increment in vehicle forward direction, lateral direction of car and vehicle day；

Acceleration conversion equipment, for the speed increment after decomposition to be converted into acceleration；

Collision detecting device, for carrying out collision detection to vehicle forward direction and/or transverse direction.