FR2905313A3 - Motorized vehicle e.g. three-wheeled scooter, controlling method, involves monitoring movement characteristic and stability criterion of vehicle, and sensing change in movement characteristic e.g. velocity, of vehicle - Google Patents

Abstract

The method involves monitoring a movement characteristic e.g. velocity and a stability criterion of a vehicle e.g. three-wheeled scooter. A change in the movement characteristic of the vehicle is sensed, when the stability criterion and the change in the movement are greater than respective preset values. A change is caused in the velocity of the vehicle so that the criterion is no longer greater than the preset value. A magnitude of the velocity of the vehicle is decreased, and a vehicle speed command is provided to a computerized controller for achieving a desired vehicle speed.

Description

1 SAFETY CONTROL SYSTEM FOR ELECTRIC VEHICLE DOMAINE DE

  THE INVENTION The invention relates to a safety control system for electric vehicles, in particular speed control systems of a vehicle. BACKGROUND OF THE INVENTION US-6,491,122 discloses an electric scooter having a switchable propulsion system between two modes, one that allows a higher maximum speed than the other. The mode is selected by a button operated by the user. A steering angle sensor and a tilt sensor are provided which prevent the user from selecting the high speed mode during a steep turn or when traveling downhill or across slopes. The steering angle sensor output feeds a controller that can impose on the propulsion system, in the low speed mode, a limit that decreases progressively as the steering angle increases. The intention is to provide the vehicle with a higher speed when moving on relatively flat terrain and in a relatively straight line, without creating a potentially unstable situation during a steering or moving on an inclined surface. EP-0 321 676 discloses a three-wheeled scooter type electric vehicle. The scooter has an angular position sensor on the directional front wheel that measures its position relative to the chassis. The output signal of the angular position detector is supplied to a control controller so that the speed is reduced as the steering angle increases. US 6,615,937 discloses a motorized wheelchair with individually controllable left and right wheels that is controlled by a joystick for entry of speed and direction controls. The wheelchair includes a steering degree response sensor and forward / reverse, lateral displacement, and vertical displacement acceleration sensors that are integrated into a feedback loop servo system to control the opposing wheels in a manner that is differential. Wheelchair travel stability is improved by reducing / eliminating the probability of the wheelchair pivoting and tilting while moving. SUMMARY OF THE INVENTION In this application, the following terms are used: Maneuvering (of the vehicle) any change in a uniform linear or circular displacement of the vehicle; Steering system: means to change the direction of movement of the vehicle. The steering system can be controlled directly by the user or indirectly via a controller.

  Direction parameter 0: a parameter characterizing the operating condition (status) of the steering system. It is assumed that 0 = 0 produces a straight linear motion of the vehicle. The parameter 0 can be literally the angle of the handlebar of the scooter, or that of a directional wheel, or the front wheels of a car.

However, 0 can also be interpreted as the difference between the rotation speeds of the left and right wheels if they are controlled independently. According to one embodiment of the invention, a control method of a motorized vehicle comprising the control of a movement characteristic (such as the speed, without being limited to this movement) and a criterion of motion is proposed. stability of the vehicle, detecting a change in this motion characteristic of the vehicle, and if the stability criterion and a change in the motion characteristic exceed respective predefined values, changing the speed of the vehicle (eg decreasing the speed of the vehicle and / or changing the direction of the vehicle) so that the stability criterion is no longer above the predefined value. According to one embodiment of the present invention there is provided a method of controlling a motor vehicle whose steering is controlled by a human being, the vehicle comprising an electric propulsion system controlled by a computerized control and a steering system. . The user provides vehicle speed control to the computerized control to achieve a desired vehicle speed and steering control to the steering system. The method comprises periodically measuring and / or calculating values of a set of physical variables comprising at least one characteristic variable of a vehicle maneuver and / or an external condition; storing these values so that a set of current values and at least one set of past values of the physical variables are available; calculating a future prediction of a vehicle stability condition using current and past values and time equations of vehicle motion; comparing the predicted condition with a predefined security criterion; and, if the safety criterion is satisfied, controlling the speed of the propulsion system to achieve a vehicle speed corresponding to the vehicle speed control; or, if the stability criterion is not satisfied, controlling the speed of the propulsion system to achieve a vehicle safety speed so that the safety criterion is met. The vehicle safety speed can be calculated by reversing the equations of motion using the safety criterion as the input data. The set of physical variables can include the speed of the vehicle. The physical variable characteristic of a maneuver may consist of the lateral acceleration of the vehicle and / or the degree of steering of the vehicle.

The set of variables may further comprise the lateral angle of slope of the terrain and / or the angle in the direction of forward movement of the terrain. The speed of the vehicle can be measured and / or calculated using one or more of the following measures. Measuring the current and / or the electrical voltage of the propulsion system; - measurement of the rotational speed of the engine used in the propulsion system; measuring the speed of rotation of a wheel of the vehicle; - the speed of movement of the body of the vehicle relative to the ground. In one embodiment, the method is used with a mechanical steering system with an operating status characterized by a direction parameter (angle) 0 in which the steering control consists of a change A0 of the direction parameter 0 imposed by the user independently of the computer controller. The set of variables may further include the direction parameter 0 and the imposed change A0. In another embodiment, the method uses a direction controlled by the computer controller, wherein the direction control consists of a change A 0 of the direction parameter 0 supplied to the controller by a suitable user interface. The set of variables may furthermore comprise the direction parameter 0 and the direction control A0. If the safety criterion is satisfied, the steering system can be controlled to provide the steering control. If the safety criterion is not satisfied, both the speed of the propulsion system and the steering parameter 0 can be controlled to achieve a vehicle safety speed and a safety steering parameter so that the safety criterion is met. be satisfied. The method may be used with a propulsion system comprising independently controlled left and right wheels of the vehicle and a steering system including means for individually controlling the rotational speeds of the left and right wheels of the vehicle. The direction parameter 0 is reached in this case by controlling the rotational speeds by the computer controller. Alternatively, the method may be used with a steering system comprising a servo control for turning the wheels of the motor vehicle. In this case, the direction parameter (angle) 0 is obtained by controlling the servo control by the computer controller. In each embodiment of the method, when the safety criterion is not satisfied and the speed of the propulsion system is controlled to achieve a vehicle safety speed and a safety steering parameter so that the criterion of If safety is satisfied, the controller can impose a substantially uniform slowing down condition of the vehicle. The method may also include an initial programming step of the computer controller with characteristic data of the vehicle and / or the user as an object. In another aspect of the present invention there is provided a control system for controlling a motorized vehicle driven by a human user, the vehicle having an electric propulsion system controlled by a computer controller and a steering system. The user provides a vehicle speed control to the computer controller to achieve a desired vehicle speed and steering control to the steering system. The control system may include sensors for periodically measuring and / or calculating values of a set of physical variables comprising at least one variable characteristic of a vehicle maneuver and / or an external condition; storage means for storing the values so that a set of current values and at least one set of past values of the physical variables are available; calculating means for calculating a future prediction of a vehicle stability condition using the current and past values and the vehicle motion equations; computing means for comparing the predicted condition with a predetermined security criterion; and safety control means designed to, if the safety criterion is not satisfied, generate a vehicle safety speed command and override the vehicle speed control so that the safety criterion is satisfied. . The system may further include sensors for periodically measuring and / or calculating current values of vehicle speed. These sensors may include one or more of the following: current and / or voltage electrical sensor for the propulsion system; rotational speed sensor associated with a propulsion system engine; rotational speed sensor associated with a wheel of the vehicle; vehicle ground speed sensor. The system may comprise, among the sensors, a lateral accelerometer and / or a sensor for measuring the degree of steering of the vehicle. The system may further comprise a sensor for measuring the lateral slope angle of the terrain and / or a sensor for measuring the slope in front of the terrain.

In one embodiment, the control system is used with a mechanical steering system 29053138 characterized by a direction parameter (angle) 0 in which the steering system is adapted to change the steering angle θ by a control direction (change AO) imposed by the user directly and independently of the computer controller. The control system may include a sensor for measuring the steering angle θ or the change A0. In another embodiment of the control system, the computer controller is adapted to control the steering parameter 0 and the control system is provided with a user interface adapted to input the steering control (change AO) into the controller computerized. The interface may be for example a joystick, a head movement sensor or a handlebar sensor. The sensors may comprise a sensor for measuring the direction parameter O. In this embodiment, the safety control means may be designed to, if the safety criterion is not satisfied, generate a combined speed command of 20. security and safety management and also override the user's direction control so that the safety criterion is met. In one case, the propulsion system may comprise left and right wheels of the vehicle controlled independently, while the steering system comprises means for the individual control of the rotational speeds of the left and right wheels. The computer controller is designed to maintain the steering parameter 0 by controlling the rotational speeds.

In another case, the steering system may comprise a servocontrol for rotating the wheels of the motor vehicle. The computer controller is then designed to maintain the direction (angle) parameter 0 controlling the servo. In all embodiments, the control system may include means for programming the computer controller with data characterizing the vehicle and / or the human user as a solid body. In one embodiment of the invention, the system may indicate to the driver of the vehicle whether the stability criterion and the change of motion in the motion characteristic are above predefined respective values, so that the driver can act for stabilize the vehicle. For example, the control system may further include alarm means to inform the user of the detection of a predicted critical condition and / or to override a vehicle or steering control speed, for example a visual, auditory or vibrating signal The control system may also include means for calculating a safety margin for changing the steering parameter 0 according to the current values of the physical variables including the current speed of the vehicle and indicating means for informing the user. on the safety margin. For example, a series of switchable emitter / reflector light elements can be usefully arranged in the user's field of view.

The conditions under which the stability of the vehicle may be lost depend on variables such as speed, inclination of the ground, and so on. Similarly, the rate at which instability approaches is a function of these variables. Attempts to prevent instabilities are much more effective when the controller uses the prediction method of the present invention. Without predicting future conditions, the vehicle is handicapped, when compared to a vehicle using a command predictor, in one of the following ways: - control of the vehicle will more often be lost; the controller will use greater safety margins to limit the speed (or cornering angle) making the vehicle soft.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention and to show how it can be practically implemented, embodiments of the invention will now be described, in an illustrative and nonlimiting manner, with reference to FIG. 1 shows a four-wheeled golf car controlled by the method according to the invention, FIG. 2 is a schematic representation of the speed / power control of the golf car of FIG. 1, FIG. 3 is a diagram of the input data in the predictor-controller of the present invention, FIG. 4 is a diagram of the transverse forces acting on the golf car of FIG. 1, FIG. three wheels controlled by the method according to the invention, Figure 6 is a schematic representation of the speed / power control of the three-wheeled scooter of Figure 5, the Fig. 7 shows an electric wheelchair controlled by the method according to the invention, Fig. 8 is a schematic representation of the speed / power control of the electric wheelchair 10 of Fig. 7, Fig. 9 is a representation of the data entered in the Figure 10 shows an electric car with an electro-mechanical steering controlled by the method according to the invention, Figure 11 is a schematic representation of the speed / power control of the car. FIG. 12 is a diagram illustrating the lateral accelerations acting on the golf car of FIG. 1. DETAILED DESCRIPTION OF THE EMBODIMENTS FIGS. 1 and 2 show a golf car 25 in FIG. four wheels 10 as an example of a mechanically driven electric motor vehicle. The car 10 has a pair of rear wheels 12 controlled by a motor 14 (shown in FIG. 2) and a pair of front wheels 16 which can be manually steered with the steering wheel 18. The motor 14 controls the rear wheels 12 via a differential (not shown) to allow the wheels 12 to turn at different speeds in a turn. The motor 14 may comprise a reducer or the like to reduce the rotational speed of the electric motor itself to that of the wheels 12. The electric motor may be a single motor 5, for example a permanent magnet motor and brush contact of the type direct current or a non-contact brush motor of AC or DC type. The user sits on the seat 20 and drives the vehicle 10 by the steering wheel 18. By turning the steering wheel 18, the user directly rotates the front wheels 16. The user controls the speed of the vehicle 10 by a pedal 22 swivel mounted on the floor under the steering column. The pedal 22 comprises a sensor 24 which detects the position of the pedal. The more the pedal 22 is depressed, the higher the speed. A selected speed signal (vehicle speed control) generated by the sensor 24 is transmitted to the controller 26 which controls the electric motor to obtain the selected speed.

In FIG. 3, the control 26 is a servocontrol capable of performing calculations in real time. The controller 26 periodically measures the motor speed either by detecting current and / or voltage 27 or receiving speed indication signals from the rotational speed sensor 28 such as a tachometer, encoder, etc. The controller 26 calculates the vehicle speed from the engine speed and gear reduction ratio. It is also possible to obtain the speed of the vehicle by detecting, for example, the speed of rotation of the wheels 12 or other rotating portions of the vehicle and supplying the signal 29 to the controller 26. The controller 26 may use the calculated vehicle speed in return to reach the selected vehicle speed. The control system of the present invention may further comprise at least one sensor of a mechanical steering vehicle maneuver 10, for example an angular velocity sensor 32 which measures the degree of steering of the vehicle 10. It may occur for example in the form of a gyroscope. As indicated above, in one embodiment of the invention, the system can indicate to the driver of the vehicle whether the stability criterion and the change of a motion characteristic are above predefined respective values, so that the driver can act to stabilize the vehicle. For example, the control system may further include alarm means (which may be integrated with the controller 26, for example) to inform the user of the detection of a critical condition prediction and / or in addition to a control of speed or direction of the vehicle, for example a visual signal, audio or vibration. In one embodiment, the control system of the invention can be of very simple construction. All of the sensors described above or below, or any combination thereof, such as speed sensors, accelerometers or the like can be used to detect whether speed or acceleration (or any other parameter) is considered dangerous or likely to jeopardize the stability of the vehicle and the driver. This sensor may be operatively connected to the alarm means (e.g. controller 26) to provide an alarm to the driver. For example, if the sensor detects a stability parameter of the dangerous vehicle or conductor or it may be dangerous, the alarm means may emit an intense audio alarm (or a visual alarm such as flashing lights). The driver can react instantly to the alarm to slow down or bring the vehicle back online without any non-human means (such as a control system) being required to slow down the vehicle. Vehicle control may be lost can occur in a very short time. Therefore, the control samples the sensors periodically, at short, repeated time intervals, and calculates prediction values of the motion variables such as, for example, speed, angular rate of rotation, lateral acceleration, etc. for a near future moment, and thus "anticipating" the behavior of the vehicle. The prediction values are obtained using the current values of the motion variables and the most recent information on the rate of change of these variables using the vehicle motion equations. By way of example, the steering degree w can be predicted: col + (dw / dT) (T2-T1) where w1 is the angular velocity measured at the current moment T1; c02 is the angular velocity predicted for the moment T2> T1; dw / dT is the current value of the rate of change of the angular velocity.

The rate of change of the angular velocity can be calculated in many ways from the current and past stored angular velocity measurements. For example, linear extrapolation or polynomial extrapolation or any other suitable mathematical approximation may be used.

As soon as the controller has calculated the prediction values of the motion variables, they are used to calculate the predictions of forces and moments to which the vehicle will be subjected. The predictions of forces and moments form a prediction of the condition of the vehicle that characterize its behavior. The control system has a stability criterion that is programmed into the controller and is used to estimate the condition prediction. If the condition prediction does not meet the stability criterion, the vehicle is expected to lose stability or at least begin to lose stability. Such a condition prediction is called a critical condition. If the command detects a critical condition prediction, it forces the engine to shift to a "safe speed" and then changes the vehicle speed to a safe speed by overriding the speed command defined by the speed controller. user. The vehicle safety speed can be calculated in real time by the controller for the current combination of the 25 motion variables and other given conditions, for example by inverse resolution of the motion equations. Imposing a safety speed stops or reverses the development of an out-of-control situation. If the forces and moments are in accordance with a condition prediction in which the stability criterion is satisfied, the controller forces the motor to control the speed of the vehicle.

As shown in FIG. 4, the golf car of FIG. 1 will be out of control or lose stability (tilt) when the destabilizing moment MD with respect to the outside wheel is greater than the gravity stabilizing moment. MS: M2 = (mVw + mgsin (a)). L2 MS = m. g. cos (a). (L1 / 2) where V is the measured or calculated speed of the vehicle 10 w is the angular velocity of the vehicle m is the mass of the vehicle and the passenger at the center of gravity g is the acceleration due to gravity a is the angle Lateral slope 15 L1 is the track width L2 is the height of the center of gravity above the ground. If the lateral slope angle is not available, the above calculation is performed assuming a = 0 or a negligible angle. In this way, the results will be less accurate but will however improve the stability of the vehicle. Thus, the stability criterion is in this case MDMS whereas the prediction of a critical condition is MD> MS.

Similar improvements in stability can be obtained by using the above "anticipation" method with sensors measuring other physical parameters. Such a sensor may for example be an accelerometer. Greater lateral acceleration would be indicative of greater centrifugal destabilizing force.

Another example is shown in dashed lines in FIGS. 2 and 3. A sensor 30 can monitor the directional position of the front wheels 16 by measuring the steering angle θ of the steering wheel 18 or by monitoring the position of an element. suitably positioned steering mechanism related to the front wheels 16. A larger steering angle causes a greater steering of the vehicle. A response of the vehicle according to the directional angle θ or its increment A0 may be initially programmed into the controller. For example, the response of the degree of deflection can be programmed by a function o = co (00, T, V). The type and coefficients of these functions can be determined by testing the vehicle with a set of 1.5 values for steering angles and speeds and subsequent regressive analysis, a technique well known in the state of the art. Further improvements in stability can be achieved by using additional slope sensors.

The lateral slope angle can be measured by a lateral slope sensor and can also be indirectly measured using the values of a steering degree sensor and a lateral accelerometer. The centrifugal acceleration calculated from the steering degree sensor can be compared to the values of the lateral accelerometer to detect the component of acceleration due to gravity on the accelerometer and hence the slope angle. The lateral slope angle can also be measured indirectly using the vertical and lateral accelerometer values. Similar "anticipation" methods for predicting future motion may use the advance 2905313 1.8 slope information to predict deterioration of stability in case of strong deceleration on a downward slope or strong acceleration on an upward slope. The forward slope angle can be measured by a forward / backward slope sensor or can be measured indirectly from the vertical and forward / backward accelerometer values. A penteavant angle can be used to predict deterioration of stability under strong cornering deceleration. Then, the controller can control the speed of the vehicle to achieve acceleration and deceleration that provide stability. The controller of the present invention can be programmed with the data necessary for calculating motion equations. Such data may include, but is not limited to: - data characterizing the vehicle as manufactured, such as weight (mass), moments of inertia, center of gravity position, track width, wheelbase, wheel diameter, etc .; data characterizing the user and / or the payload, such as weight, moments of inertia, the position of the center of gravity, etc., and; Other coefficients (constants) of various functions describing the behavior of the vehicle and relevant to solving the motion equations. Alternatively, some or all of these data may be present in the controller in averaged or non-modifiable form.

The control system described above can also be applied to other mechanically-driven electric vehicles, including three-wheeled vehicles, such as off-road vehicles, go-karts, club cars, vehicles for vehicles and vehicles. persons, push-pull electric powered equipment systems, front or rear motorized equipment for manual wheelchair control, electric forklift control systems, electric forklift trucks, cars electric child rickshaws, electric three-wheel rickshaws, electric urban vehicles, etc. Figures 5 and 6 show a three-wheeled scooter 40 which uses a control system according to the invention. A motor 14 controls a pair of rear wheels 42 and a single front wheel 46 is manually controlled in the direction by a steering column 48. The motor 14 controls the wheels 32 via a differential (not shown) to allow 20 wheels turn at different speeds in cornering. The user sits in the seat 50 and directs the vehicle 40 by the handles 44 of the steering column 48. By turning the steering column 48, the user rotates the wheel 46 directly.

The user controls the speed by the actuator arm 52 pivotally mounted on the steering column 48 and near the handles 44. The actuator arm 52 actuates a sensor 54 which detects the direction and amplitude of movement of the actuator arm. The further the actuator arm 52 is pushed towards the handle 44, the higher the selected speed. The left portion of the actuator arm 52 is pushed toward the adjacent handle 44 for forward movement and the right portion for backward movement. This arrangement can also be reversed or a single-ended accelerator can be used. The speed selected by the actuator arm 52 is transmitted to the controller 26 which controls the motor 14. In the case of a three-wheeled vehicle, the tilting axis is not parallel to the direction of travel as in FIG. 4. This can be taken into account by changing the coefficients in the previous formulas. Thus, forward acceleration will have a component in lateral stability. Electric vehicles using the control system of the present invention may also be controlled by a front wheel drive engine or a single front wheel, such as a three-wheeled scooter in which the front wheel is driven by the engine. In this case, propulsion and steering are both applied to the front wheel. The control system and method described above can also be applied to other types of electric vehicles in which the steering is not controlled directly by the user, but indirectly through the same system of control. command. A steering command (turn) may be sent by the user via electrical control units such as a joystick or steering wheel whose position is measured by a sensor or other means. FIGS. 7, 8 and 9 show a motorized wheelchair 60 comprising a frame 62, a seat 64, a set of freewheels 66 and drive wheels 68, 70 controlled respectively by motors 72, 74. The motors are controlled by a controller 76 implementing the method according to the present invention and comprising a driver control device 78. The controller 78 is shown as a joystick but may be, inter alia, a head movement sensor or a steering column sensor. The driver control device 78 allows the driver to select speed and steering commands and to send them to the controller 76 via an electrical cable or via a wireless data transmission such as than radio, ultrasound, infra-red, etc. The controller 78 may also be an integral part of the controller 76. As in the previous examples, the wheelchair control system may comprise a manoeuverable sensor, such as, for example, an angular velocity sensor 32. controller 76 can separately control motors 72 and 74 to separately drive each wheel 68, 70 forward, backward or to stop them.

By controlling different speeds, or even different directions of recitation, for the left and right wheels, the controller 76 can move the powered wheelchair 60 at the selected speed in forward or reverse and with a selected steering angle.

The user sits on the seat 64 and provides speed and steering commands to the controller 76 through the controller 78. Using the speed and steering controls, as well as the measurements and calculations described. higher (but by obtaining the speed of each wheel separately), the controller 76 "anticipates" to predict the behavior of the vehicle. As above, if a critical condition prediction is detected, the controller overrides the user's commands. However, in this case, the controller 76 may impose on the electric motors not only a "safety speed" but also a "safe steering angle" (or steering speed). This ability to control both the linear speed and the steering angle can be used to optimize control, for example by imposing an additional condition such as substantially uniform deceleration. Another type of electric vehicle with electric steering is shown in FIGS. 10 and 11. An example of a motor vehicle with an electromechanical steering is a four-wheeled car 80. The car 80 has a pair of rear wheels 82 controlled by a motor 14 (shown in FIG. 11) and a pair of front wheels 86 which can be electrically driven by a servocontrol 88. A mechanical flywheel 89 with a steering wheel angle sensor 90 is connected to a controller 96 which implements the method according to the present invention. In the same way as for the vehicle shown in FIGS. 1 and 2, the vehicle 80 includes a spring pedal 22 with a sensor 24 also connected to the controller 96, for controlling the speed. The controller 96 controls, via respective sensors 90 and 24, the servomechanism 88 and the motor 14 according to the selected steering angle and speed commands provided by the user. The security control method is implemented in the same manner as in the example of the motorized wheelchair 60.

In all versions of the controller, the user can be informed about the critical condition prediction or about overriding a speed or direction command by switching on an alarm light, voice signal or otherwise. This allows the user to change the control data sent to the controller. Likewise, a safety steering angle can be calculated in real time and indicated (for example in the form of a row of LEDs) to the user in relation to the current speed of the vehicle. Although a description of specific embodiments has been presented, various changes may be contemplated without departing from the scope of the present invention. For example, the operation of the system according to the present invention can be simplified by not including the linear velocity V in the control variables. Such a system can use only lateral acceleration measurements (in this case lateral acceleration is the stability criterion or is a factor which determines the stability criterion) and predict lateral acceleration. As shown in Fig. 12, a critical condition prediction in such a case occurs when the moment of destabilization MD on the outer wheel is greater than the gravity settling moment MS. MD = m. al. L2; MS = m. g. cos (a (L1 / 2); MD> Ms where m is the mass of the vehicle and the passenger applied to the center of gravity 30 g is the acceleration due to gravity aL is the lateral acceleration a is the slope angle lateral 2905313 24 L1 is the track width L2 is the height of the center of gravity above a horizontal terrain.

Claims (13)

  An apparatus for controlling an electric propulsion system of a motor vehicle comprising: - a sensor for tracking a motion characteristic and a stability criterion of a vehicle, and - a sensor for detecting a change in the motion characteristic of the vehicle. vehicle, characterized by a computer controller in communication with said sensors, wherein, if the stability criterion and the change in the motion characteristic are above predefined respective values, said computerized controller causes a change in the speed of the vehicle of so that the stability criterion is more than the predefined value.   2. Apparatus according to claim 1, characterized in that said computer controller is adapted to reduce the speed of the vehicle.   3. Apparatus according to claim 1, characterized in that said computerized controller is adapted to change the direction of the vehicle.   Apparatus according to claim 1, characterized in that the sensors provide a vehicle speed control to said computer controller to achieve a desired speed of the vehicle. 2905313 26   Apparatus according to claim 3, further comprising a steering system, characterized in that said computerized controller provides steering control at least indirectly to said steering system. 5   Apparatus according to claim 1, characterized in that said computerized controller obtains data which is characteristic of at least one maneuver of said vehicle and an external condition; stores said data so that a set of current data and at least one set of past data are available; calculates a future stability condition prediction of said vehicle using said current data and said previously stored past data and time motion equations for said vehicle; compares said condition prediction with a predefined security criterion and, if the predefined security criterion is not satisfied, causes a change in the speed of the vehicle so that the security criterion is satisfied.   Apparatus according to claim 1, characterized in that the movement characteristic includes the speed.   Apparatus according to claim 1, characterized in that the movement characteristic includes lateral acceleration.   Apparatus according to claim 7, characterized in that the motion characteristic further comprises angular acceleration. 2905313 27   Apparatus according to claim 6, characterized in that the data comprises at least one of the lateral slope angle of a terrain, the pitch angle of the terrain, the vehicle speed and the steering degree. of the vehicle.   Apparatus according to claim 5, characterized in that said steering system is a mechanical steering system with an operational mode characterized by a direction parameter 0 and wherein said steering command is a change A0 of the steering parameter O .   12. Apparatus for controlling a motor vehicle comprising A sensor for tracking a motion characteristic and a stability criterion of a vehicle, and a sensor for detecting a change in the motion characteristic of the vehicle, characterized in that said computerized controller indicates to a driver of the vehicle whether the stability criterion and the change in the movement characteristic are above predefined respective values so that the driver can act to stabilize the vehicle. 25   Apparatus according to claim 12, characterized in that said computerized controller provides at least one of a visual signal, an audio signal and a vibratory signal to the driver.