JP2696416B2 - Car rollover prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Purpose of the Invention and Conventional Techniques A centrifugal force acts on a car running on a curved road, and often causes a rollover accident. The centrifugal force fluctuates depending on the speed, weight, turning radius, etc. of the vehicle. However, the degree of its action has conventionally been intuitively judged from the experience of the driver, and scientifically appropriate measures could not be taken.

The present invention relates to a device for preventing a rollover accident.

B. Structure and operation of the invention If all the centrifugal force is spent for rollover of the vehicle (that is, ignoring the effect of causing the vehicle to slip outward in the turning radius direction, etc.), FIGS. , Turn right,
A moment mα _c H (m is the entire vehicle mass, α _c is the normal acceleration corresponding to the turning curve, and H is the height of the center of gravity G) acts about the line connecting the outside installation point PP as an axis. .
In contrast, mgD _L (D _L is the distance between the vertical surface and the center of gravity to the road contains PP, g is the gravitational acceleration) acting in the direction of moment of stabilizing the vehicle. Therefore, if mα _c H> mgD _L ∴α _c > gD _L / H (1), the car will roll over.

Here, H is the minimum load (vehicle weight +
Since the fluctuation between the driver's weight) and the maximum load is small, it can be treated as a constant value, for example, by taking the extreme value on the safe side (the maximum value of H, that is, the value at the minimum load). likewise treats g and collectively g / H is a constant value as the predetermined value, further, is replaced with k ₁ taking into account the overall safety factor to the expression (1) alpha _c> k ₁ D _L (2).

Therefore, the rollover can be prevented by calculating the data obtained by an appropriate detection device and operating the safety device when the above equation is satisfied.

FIG. 4 is a block diagram showing an example of the configuration of such an apparatus.

The sprung loads w _1u , w _2u and w applied to the wheels shown in FIG.
_3u , w _4u are appropriate load detecting mechanisms (for example, strain gauges, load cells, etc.) 31, 32, 33, 3
4, the computing unit 1 selects the values w ₁₀ , w ₂₀ , w ₃₀ , w ₄₀ (described later) at the time of specifying each load by using them as inputs, and calculates the resultant force W _u thereof. The arithmetic unit 2 calculates the distance L and the distance d between the spring installation points in the front-rear direction and the left-right direction.
(These are constant for each vehicle type, are known from design or actual measurement, and are input by appropriate setting mechanisms 41 and 42.) From the position of W _u , that is, the position of the center of gravity _{Gu in} the horizontal direction (front and rear) Direction l _1u ),
(Left-right direction d _1u ) is calculated.

However, since these are the results obtained from the specifications of the sprung load relation, they are not data of the weight and the center of gravity of the entire vehicle. In order to determine the center of gravity of the entire vehicle, the unsprung load must be considered.

In addition, the above calculation of the center of gravity position, the load applied to each wheel changes while the vehicle is under acceleration, and is affected by pitching and rolling due to road surface irregularities and obstacles during running, Stores the detected and calculated values at rest,
Hold.

Since the inclination of the road surface also affects the calculation result, the detection value in the horizontal state is used.

Therefore, in addition to the load detection value, the arithmetic unit 1 receives a speed V obtained from an appropriate speed detection mechanism 35 (of course, it may be obtained from a speedometer), and a condition obtained from an appropriate inclination detection mechanism 36. Enter V = 0, that is, when there is no input from the speed detection mechanism and when there is no input from the horizontal, that is, when there is no input from the inclination detection mechanism (a slight allowable limit is set so that no signal is emitted within a certain angle from horizontal. Only) w
_{10 to} w ₄₀ are selected and input to the arithmetic unit 2. The value at the specific time means the output under this condition (the value at the time other than the condition is sent to the arithmetic unit 11 in FIG. 5).

Unsprung load is constant for each vehicle model, the position of the calculation or actual measurement in design and the weight W ₁ its center of gravity G ₁ (the longitudinal direction l
₁ and the left and right direction d ₁ ) are obtained, and these are input to the arithmetic unit 3 by the setting mechanisms 43, 44 and 45. Computing machine 3, the other input w _u, l _1u, the position of the center of gravity G of the whole car weight W and a d _1u (longitudinal direction l _F, the left-right direction d _L) is readily determined by the resultant force calculation of W _u, W _l .

Whether the turning direction is right or left corresponds to the turning direction of the steering wheel,
Further, the rotation of the handle can be easily detected by an appropriate rotation angle detection mechanism (for example, a rotary encoder or the like. In this operation, only the rotation direction is required, and the accuracy of the angle is not required, so that a simpler detection mechanism can be used). The arithmetic unit 4 outputs d _L or d _R (= d−d _L ) depending on whether the rotation of the handlebar rotation angle θ detected by the rotation angle detection mechanism 37 is right or left (+ or −) (for example, θ). > no signal is emitted from the rotation angle detection mechanism in operation machine 4 is 0, while the operation unit 4 sends the operation unit 5 as an output an input d _L, constant signal is input in other cases, the when the calculation device 4, such as by outputting a d _R from the d and d _L). D _L
In operation machine 5, the d _L, obtained by the addition (input setting mechanism 46) spacing D _w readily known from design or measured at a constant for each vehicle model. The computing unit 6 calculates k ₁ D _L using this and the constant k ₁ which is an input from the setting mechanism 47. The computing unit 7 compares the two inputs and, when α _c > K ₁ D _L , activates the safety device 51 (releasing the accelerator, issuing an alarm, etc.).

Naho, the w ₁₀ to w ₄₀ by the operation unit 1 is elected stationary, whereas it is only during the horizontal, instant conditions of θ is input to the arithmetic unit 4, and k ₁ D _L is calculated The moment at which the arithmetic operation is performed by the arithmetic unit 7 is traveling, and there is always a time lag during the traveling (the moment from the input of θ to the arithmetic unit 4 to the output of the arithmetic unit 7 is instantaneous). Therefore, W _u , w _{10 to} w ₄₀ , or arithmetic unit 2
The output of the arithmetic unit 3 and the like must be stored and held until the next stationary or horizontal state.

Of course, during the above, the units of each input must be coordinated to take the same step. Further, the computing unit may divide or consolidate the corresponding functions as appropriate, or may convert each expression equivalently (for example, by transposing), and change the contents and combinations of the computing units accordingly. Also, for example, d
Output d _2u instead of _1u (the same assembling philosophy of arithmetic expression)
The same final effect can be obtained by calculating d _R by inputting d _2l instead of the input d ₁ of the arithmetic unit 3. These are the same in the following examples.

The above is the case where the height H of the center of gravity is treated as a known constant value. However, if the load is large like a truck and the fluctuation thereof is severe, it cannot be passed. Therefore, H is automatically detected as follows.

First, the height H _u of the center of gravity G _u of the sprung load from the spring installation plane
Ask for.

Loads w _{1u to} w _4u detected at each of the four wheels are sprung loads
A component force of the W _u, respectively sediment balanced with the reaction force at that point, over the next force calculation, horizontal position l _1u of G _u, d
_1u is calculated by the arithmetic unit 2.

Now, as shown in FIG. 3, considering that the vehicle is on a slope having an inclination angle of Θ, the angle formed by the gravity line _Gu D with the gravity line _Gu C when horizontal is equal to the inclination angle. _u = CD / _tanΘ However, CD = AD-AC = AD -l in _1u, also AD = from the equilibrium conditions of the moment _{(w 3u + w 4u) L} / W u So _{H u = {(w 3u +} w 4u) L / W _u −l _1u ｝ / tanΘ (3) This is the result of taking the moment about the line connecting the front-wheel-side spring installation points. Of course, the same result can be obtained by taking the moment about the rear-wheel side. (W _u = w _1u + w _2u + w _3u + w _4u , L
= L _1u + l _2u , they all return the same result).

FIG. 5 is a block diagram showing an example of an operation for obtaining the above calculated value. In the above expression, w _3u + w _4u is
W _u is also calculated by the arithmetic unit 1, and l _1u is calculated by the arithmetic unit 2. Since Θ is obtained from the inclination detecting mechanism 36 and the known value L is obtained as an input from the setting mechanism 41, _Hu is calculated by a series of calculators (the explanation is omitted because it is obvious from the figure).

However, H _u as the is a height of the center of gravity of only the spring, but all cars of the center of gravity height H must be a height of the center of gravity of W is a resultant force of the spring on the load W _u and the unsprung load W _1, The method of obtaining the information is already described in the applicant's “anti-rollover device” filed on April 16, 1990, and will not be described.

Naho, construction of anti-rollover device when using this H _u, for example the fourth input to the in arithmetic unit 6 in the figure, and kD _L / H output of the arithmetic unit, the criteria for calculating machine 7 alpha _By setting _c > k ₁ D _L / H, it is sufficient (of course, the calculation content of the calculator 6 changes).

C. Advantageous Effects of the Invention As exemplified above, according to the present invention, the rollover accident prevention, which has conventionally depended only on the driver's intuition, is automatically performed. ,
This is extremely useful in social life, such as reducing driver fatigue, which also enhances the effect of preventing accidents.

[Brief description of the drawings]

FIG. 1 is a plan view of a vehicle showing a positional relationship between wheels, a load, a center of gravity, and the like. FIG. 2 is the same rear view. FIG. 3 is a left side view of the same slope. FIG. 4 is a block diagram showing an example of a calculation by the apparatus of the present invention. FIG. 5 is a block diagram showing an example of _Hu calculation. 1,2,3,4,5,6,7 are computing units respectively. 11,12,13,14,15 are computing machines respectively. 31,32,33,34 are load detection mechanisms respectively. Three
5 is a speed detection mechanism, 36 is an inclination detection mechanism, 37 is an angle detection mechanism, and 39 is a normal acceleration detection mechanism. 41, 42, 43, 44, 45, 46, 47 are setting mechanisms, respectively. 51 is a safety mechanism.

Claims (1)

(57) [Claims] 1. A sprung load and a horizontal position of a center of gravity of the sprung load are determined from a static load applied to four wheels of a vehicle under a load detected by a suitable load detecting device and a spring position (location of each spring). From these, the unsprung load and the position of the center of gravity, the load of the entire vehicle and the horizontal position of the center of gravity are calculated, whereby the road surface including the outer contact point PP of the outer wheel of the vehicle during turning is calculated. The distance D between the plane perpendicular to the center of gravity and the center of gravity
D _1, calculates D _R) For counterclockwise rotation, also sprung load center of gravity G _u
Of the height H _u from the spring installation plane, in a state placed on the slopes of the inclination angle Θ of inclination of the vehicle in the longitudinal direction, and a moment about the front axle of the sprung weight W _u (or at the rear axle wheels), Rear wheel (front wheel if the moment is taken for the rear wheel axle)
Is obtained from the condition of equilibrium with the moment of the load applied to the front wheel axle, and the height H of the center of gravity of the entire vehicle load is obtained from this and the known center of gravity of the unsprung load. Then, between the constant k determined in consideration of the safety factor and the normal acceleration α _c detected by an appropriate acceleration detecting device, α _c > kgD / H (g is the gravitational acceleration) or an equation equivalent thereto. An anti-rollover device for a vehicle, characterized in that safety measures such as automatically releasing the accelerator or issuing an alarm when taken hold are taken.