DE202007003164U1 - Safety control system for an electric vehicle - Google Patents

Abstract

Device for controlling an electric drive system of a motorized vehicle, comprising:
a sensor for monitoring 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 by, a computerized controller in communication with the sensor, wherein the computerized controller, when the stability criterion and the change in the movement characteristic are above predetermined values, causes a change in the speed of the vehicle such that the stability criterion no longer overshoots is the predetermined value.

Description

technical area

The The invention relates to an automated security control system for electrical Vehicles, in particular systems for controlling the speed of a vehicle.

background the invention

US 6,491,122 discloses an electric scooter with a drive system switchable between two different modes, one of which allows a higher maximum speed than the other. The mode can be selected by a user by means of an actuatable button. Further, a steering angle sensor and a tilt switch are provided which prevent the user from being able to select the high-speed mode during sharp steering or while going down or crossing downhill slopes. The output value of the steering angle sensor is transmitted to a controller, which can impose a limit on the drive system for the low-speed mode, which gradually decreases with simultaneous increase of the steering angle. The aim is to achieve a higher speed for the vehicle while moving over a relatively level ground and in a relatively straight line, without obtaining any unsafe operation during steering or on a sloped surface.

EP 0321676 discloses an electrically driven vehicle which is designed as a three-wheeled scooter. The scooter has an angular position detector on a steerable front wheel which determines its position relative to the chassis. The output signal of the angular position determiner is relayed to a driving controller, so that the traveling speed is reduced as the steering angle increases.

US 6,615,937 discloses a motorized wheelchair with individually controllable left and right wheels, whose speed and rotational movements can be controlled by means of a joystick. The wheelchair has a rotational speed feedback sensor and forward / backward motion, lateral motion, and vertical motion acceleration feedback sensors integrated into a closed loop control system for differential control of the opposing wheels. By reducing / eliminating possible wheelchair wheel skidding and tilting of the wheelchair during wheelchair movement, improved wheelchair stability is achieved.

Summary the invention

The following terms are used in the present application:
Maneuver (of the vehicle) - any deviation from a uniform rectilinear or rotational movement of the vehicle;
Steering system - means for changing the direction of movement of the vehicle. The steering system can be controlled directly by the user, or indirectly via a controller.
Steering parameter θ - a parameter which characterizes the status (status) of the steering system during operation. It is assumed that θ = 0 includes the rectilinear motion of the vehicle. The parameter θ is preferably the angle of the rotation axis of a scooter or the steering wheel or the front wheels of a car. However, θ can also be understood as the difference between the rotational speed of the left and right wheels when operated and controlled independently of each other.

Consequently is according to a embodiment The invention relates to a method for controlling an electric drive system a motorized vehicle comprising monitoring a movement characteristic, such as speed, and a stability criterion of a vehicle, detecting a change in the motion characteristic of the vehicle, and if the stability criterion and the change in the movement characteristic over according to predetermined values, will be a change in the speed of the vehicle (e.g., by reducing the speed of the vehicle and / or by change the direction of the vehicle), so the stability criterion is not longer over that previously set value.

In accordance with another embodiment of the invention, there is provided a method of controlling a motorized human controllable vehicle, the vehicle including a computer controlled controller controlled electric drive system and a steering system. Of the User issues a vehicle speed command to achieve a desired vehicle speed to the computerized controller and a steering command to the steering system. The method comprises a periodic measurement and calculation of values from a plurality of physical variables, which comprises at least one variable characteristic of a maneuver of the vehicle and / or an external state; storing the values such that a series of current values and at least a series of previously determined values of the physical variables are available; calculate a stability state of the vehicle to be expected with the aid of the current values and the last values and time-dependent equations of motion for the vehicle, comparing the determined state with a predetermined safety criterion; and, if the safety criterion is met, controlling the speed of the drive system to obtain a vehicle speed according to the vehicle speed command; or, if the predetermined safety criterion is not met, controlling the speed of the drive system to achieve a safe speed of the vehicle so that the predetermined safety criterion is met.

• – Messen des elektrischen Stroms und/oder Spannung des Antriebsystems;
• – Messen der Rotationsgeschwindigkeit des in dem Antriebsystem verwendeten Motors;
• – Messen der Rotationsgeschwindigkeit eines in dem Fahrzeug verwendeten Reifens;
• – Messen der Fahrzeuggeschwindigkeit in Bezug auf den Boden.

Conversely, the safe vehicle speed can be determined by solving the equation of motion if the safety criterion is considered a prerequisite. The series of physical variables may include vehicle speed. The physical variable characteristic of a maneuver may represent the lateral acceleration of a vehicle and / or the rotation of the vehicle. The series of variables may further include the lateral inclination angle of the floor and / or the forward inclined angle of the floor. The speed can be measured and / or calculated as follows:

• - measuring the electrical current and / or voltage of the drive system;
• - measuring the rotational speed of the motor used in the drive system;
• - measuring the rotational speed of a tire used in the vehicle;
• - Measuring the vehicle speed with respect to the ground.

According to one embodiment The method is using a mechanical steering system which is in working order Condition is characterized by a steering parameter (angle) θ, in which the steering command represents a change Δθ of the steering parameter θ, which independently from the computer-aided Control is imposed by the user. The set of variables can also the steering parameters θ and include the imposed change Δθ.

To a further embodiment The method is one with a computer-aided control controlled steering system, wherein the steering command represents a selected change Δθ of the steering parameter θ, which is transmitted to the controller by means of a suitable user interface becomes. The series of variables may also include the steering parameter θ and the Steering command Δθ include.

If meets the safety criterion is, the steering system can be controlled so that it is the steering command performs. If the safety criterion is not met, both the speed of the drive system as well as the steering parameter θ be controlled such that a safe vehicle speed and a safe steering parameter be achieved so that the safety criterion is met.

The Procedure can be with a drive system which is different driven left and right wheels of the vehicle, and a steering system, which comprises means for individual control of the rotational speed of the left and right wheels has to be used. In this case, the steering parameter θ is controlled by the rotational speeds by means of the computer-aided control achieved.

alternative For example, the method can be used with a steering system which a servo drive for rotating the wheels of the motorized vehicle having. In this case, the steering parameter (angle) θ by control of the servo drive achieved by the computer-aided control.

at each of the possible embodiments According to the invention, the controller may be a state of a substantially even speed decrease force the vehicle if the safety criterion is not met and the speed of the drive system is controlled so that a safe vehicle speed and a safe steering parameters achieved but where the safety criterion is not fulfilled.

The The method may further include programming the computerized controller with the vehicle and / or the user as such characterizing Include data.

According to a further embodiment of the invention, a control system for controlling a through a human-user controlled motorized vehicle, the vehicle having an electric computer-controlled control drive system and a steering system. The user gives a vehicle speed command to the computerized controller to obtain a desired vehicle speed and a steering command to the steering system. The control system may include periodic measurement sensors and / or means for calculating values from a series of physical variables having at least one variable of a maneuver characteristic of the vehicle and / or an outside state; Means for storing the values such that a series of current values and at least a number of previously determined values of the physical variables are available; Computer means for calculating a predicted future stability state of the vehicle by means of the current and previously determined values and the equations of motion of the vehicle; Computer means for comparing the predicted condition with a predetermined safety criterion; and suitable safety control means so that, if the safety criterion is not met, a safe vehicle speed command can be generated and the vehicle speed command can be overcome so that the safety criterion is met.

The System may include sensors for periodic measurement and / or means for Calculation of the current values of the vehicle speed include. These sensors can one or more of the following sensors include: electrical power and / or voltage sensor for the drive system; connected to the engine of the drive system Rotational speed sensor; connected to a wheel of the vehicle Rotational speed sensor; Vehicle ground speed sensor. The system may include a lateral accelerator or / and sensors have a sensor for measuring the rotation of the vehicle. The System may further include a sensor for measuring the lateral tilt angle of the floor and / or a sensor for measuring the forward facing Include angle of inclination of the soil.

According to one embodiment if the control system is used by means of a mechanical steering system, which is characterized by a steering parameter (angle) θ, where the steering system for change of the steering angle θ imposed by the user and by the computerized control independent Steering command (change Δθ) suitable is. The control system may include a sensor for measuring the steering angle θ or the change Δθ.

To a further embodiment of the control system, the computerized control is suitable for the steering parameter θ too control, and the control system has a suitable user interface for input of the steering command (change Δθ) in the computer-aided Control on. For example, the UI may look like a joystick, a head movement sensor or a "Tiller" sensor. The sensors can have a sensor for measuring the steering parameter θ. According to this embodiment Safety control means, if the safety criterion is not met, suitable for a common safe speed and safe steering command and override the user-entered steering command, so that the safety criterion is met.

To an embodiment the drive system can be independent have left and right wheels of the vehicle driven by one another, wherein the steering system means for individually controlling the rotational speeds the left and right wheels having. The computer-aided Control is suitable the steering parameter θ To maintain control of the rotational speed.

To a further embodiment The steering system can be a servo drive for turning the wheels of the have motorized vehicle. In this case, the computer-aided control suitable for this, the steering parameter (angle) θ for controlling the servo drive maintain.

In all of these embodiments The control system may include means for programming the computerized control with data representing the vehicle and / or the human user characterize as such.

According to one embodiment of the invention, the system may indicate to the driver of the vehicle if the stability criterion and the change in the movement characteristic are above predetermined values, so that the driver may take measures to stabilize the vehicle. For example, the control system may further comprise warning means for informing the user of detected early critical conditions and / or exceeding vehicle speed or steering command, for example by means of an optical signal, acoustic signal or vibration signal. The control system may further comprise means for calculating a safe limit for changing the steering parameter θ in dependence on the current values of the physical variables, including the current vehicle speed and display means for informing the user of this safe limit. For example, an array of switchable light emitting / light reflecting elements may be placed in the user's field of view.

States, in which stability the vehicle could be lost are dependent variables such as speed, slope of the ground, etc. In addition is the measure at the instability is reached, sensitive to these variables.

• – Das Fahrzeug wird öfter die Kontrolle verlieren;
• – Die Steuerung wird höhere Sicherheitsgrenzen zur Begrenzung der Geschwindigkeit (oder Drehwinkel) verwenden, was dazu führt, dass das Fahrzeug sich schwerfälliger bewegt.

Attempts to prevent the occurrence of instabilities are far more effective when the controller uses the prediction method of the invention. Without predicting future conditions, the vehicle is at a disadvantage compared to a vehicle using the controlled prediction due to the following reasons:

• - The vehicle will lose control more often;
• The controller will use higher safety limits to limit the speed (or angle of rotation), causing the vehicle to move more heavily.

Short description the drawings

to closer explanation of the invention and to show how the invention is practiced can be, embodiments below in conjunction with the drawings, the examples no restriction represent the invention.

It demonstrate:

1 a four-wheeled "golf car" which is controlled by means of the method according to the invention;

2 a schematic representation of the speed / power control of in 1 illustrated "golf cars";

3 a schematic of the input data flow in the control predictor according to the invention;

4 a scheme of the in 1 shown "Golf Car" acting shear forces.

5 a three-wheeled scooter controlled by the method of the invention;

6 a schematic representation of the speed / power control of in 5 illustrated three-wheeled scooter;

7 an electric wheelchair controlled by the method of the invention;

8th a schematic representation of the speed / power control of in 5 illustrated electric wheelchair;

9 a schematic of the input data flow in the inventive control predictor of 7 illustrated wheelchair;

10 an electric car with electro-mechanical steering controlled by the method according to the invention;

11 a schematic representation of the speed / power control of in 10 illustrated electric cars; and

12 a scheme of the "Golf Car" off 1 acting lateral accelerations

Detailed description the embodiments

In 1 and 2 is a 4-wheeled "Golf-Car" 10 shown as an example of an electromotive vehicle with mechanical steering. The vehicle 10 has two by means of a motor drive 14 (in 2 shown) driven rear wheels 12 and two front wheels 16 , which manually by means of a steering wheel 18 ge can be distracted. The motor drive 14 drives the rear wheels 12 by means of a Hinterachsengetriebes (not shown here), so that the wheels 12 can rotate at different cornering speeds. The motor drive 14 may have a reduction gear or the like to the rotational speed of the actual electric motor in dependence on the rotational speed of the wheels 12 to reduce. The electric motor may be a simple built-in motor, for example a permanent DC brushed magnet motor or an AC or DC brushless motor.

The user is sitting in a seat 20 and steers the vehicle 10 by means of the steering wheel 18 , Will the steering wheel 18 rotated, the user simultaneously turns the front wheels 16 , The user controls the speed of the vehicle 10 by means of a pedal 22 which is centrally located on the floor of the vehicle 10 is fastened below the steering wheel shaft. The pedal 22 is with a sensor 24 which determines how far the pedal is moved away. The further the pedal 22 pushed towards the ground, the faster the speed. A chosen one by the sensor 24 generated speed signal (vehicle speed command) is sent to a controller 26 transmitted, which controls the electric motor so that the selected speed is reached.

Regarding 3 is the controller 26 a servo controller, which can be used to perform real-time calculations. The control 26 periodically measures the motor drive speed either by measuring the electrical motor current and / or the voltage 27 , or by receiving indication signals from a rotational speed sensor 28 , such as a speedometer, transducers, etc.

The control 26 calculates the vehicle speed from the motor drive speed ^and the known transmission ratio. Further, it is possible to control the vehicle speed by measuring the rotational speed of other rotating parts of the vehicle, such as wheels 12 to receive and the signal 29 to the controller 26 transferred to. The control 26 may use the calculated vehicle speed as feedback of the selected vehicle speed to be reached.

The control system according to the invention may further include a sensor responsive to a maneuver of the mechanically steered vehicle 10 reacts, for example, an angular velocity sensor 32 which is the rotation of the vehicle 10 measures. This can, for example, have the shape of a gyroscope.

As previously stated, according to an embodiment of the invention, the system may indicate the ^{driver of} the vehicle when the stability criterion and the change in the movement characteristic are above the corresponding predetermined values, so that the driver can take measures to stabilize the vehicle. For example, the control system may further include warning means (which may be used, for example, in the controller 26 integrated), for example, an optical signal, an audible signal or a vibration signal, to inform the user when a previously determined as a critical state is determined and / or when the vehicle speed or the steering command is exceeded. According to one embodiment, the control system according to the invention may have a simple structure. Any of the sensors described above or below, or any combination of these sensors, such as speed sensors, accelerators or the like, may be used to determine whether the vehicle's speed or acceleration (or other parameters) are dangerous or threatening to the stability of the vehicle Vehicle and the driver. This sensor can be in direct contact with the warning devices (eg the controller 26 ) to warn the driver. For example, if the sensor detects a dangerous or threatening parameter relating to the stability of the vehicle and the driver, the warning means may emit a loud audible warning sound (or a visible warning signal such as flashing lights). The driver can respond directly to the warning signal to reduce the speed of the vehicle without the need for non-human means (such as the control system) to reduce the speed of the vehicle.

States, in where the vehicle can lose control can be very arise quickly. Therefore, check Control the sensors periodically in repeated short time intervals and calculates expected values of the motion variables, such as Speed, angular velocity, lateral acceleration, etc. for a near future moment, thus "looking forward" in the behavior of the vehicle.

wobei

ω₁

– gemessene Winkelgeschwindigkeit zum aktuellen Zeitpunkt T₁;

ω₂

– vorhergesagte Winkelgeschwindigkeit zum Zeitpunkt T₂ > T₁;

dω/dT

– aktueller wert der Änderungsrate der Winkelgeschwindigkeit.

The expected values are given by the current values of the motion variables and the most recent information about the rate of change of these variables by using equations of motion of the driving received. For example, the rotation ω can be predicted as follows:

in which

ω ₁

Measured angular velocity at the current time T ₁ ;

ω ₂

Predicted angular velocity at time T ₂ > T ₁ ;

dw / dT

- current value of the rate of change of angular velocity.

The rate of change The angular velocity can be compared in numerous ways the current and the stored previous measurements of the Angular velocity can be calculated. For example, linear Extrapolation or polynomial extrapolation or any other suitable mathematical approximation can be used.

Has the controller calculates the expected values of the motion variables, can these for the calculation of forces and moments which will act on the vehicle become. These forces and Moments represent a predictable condition of the vehicle, which characterizes the behavior of the vehicle.

The Tax system has a stability criterion, which is programmed into the controller and for the evaluation of the predicted state serves. If the predicted state is not meets the stability criterion the vehicle is expected to lose its stability or at least start his stability to lose. Such a predicted state becomes more critical Condition designated. If the controller predicted a critical Condition, it will give the engine a change in speed in a "safe Impose speed " and subsequently change the vehicle speed to a safe vehicle speed and the vehicle speed command given by the user cancel. The safe vehicle speed can be controlled by the controller in real time for the current combination of motion variables and other given ones Conditions, for example by reverse solution the equation of motion can be calculated. By imposing the safe speed, the "out of control" situation is ended or reversed become.

If the forces and moments with the predicted state where the stability criterion Fulfills is, agree, the controller will impose the speed command on the motor.

wobei

V

– gemessene oder berechnete Fahrzeuggeschwindigkeit;

ω

– Winkelgeschwindigkeit des Fahrzeugs;

m

– Masse des Fahrzeuges und der Passagiere an ihrem Schwerpunkt;

g

– Erdbeschleunigung;

α

– seitlicher Neigungswinkel;

L₁

– Spur;

L₂

– Schwerpunktshöhe über dem horizontalen Boden

As in 4 shown, the "golf car" is off 1 get out of control or lose stability (tip over) when the destabilizing moment M _D over the outer wheel is greater than the stabilizing moment M _S : M D = (m × V × ω + m × g × sin α) L 2

in which

V

- measured or calculated vehicle speed;

ω

- angular velocity of the vehicle;

m

- mass of the vehicle and passengers at their center of gravity;

G

- acceleration of gravity;

α

- lateral inclination angle;

L ₁

- Track;

L ₂

- Center of gravity above the horizontal ground

If the side angle of inclination is not available, the one shown above Calculation with an assumed angle of α = 0 or a slight angle accomplished become. The results will not be that accurate, however nevertheless provide improved vehicle stability.

Thus, in this case, the stability criterion M _D ≤ M _S , while the critically predicted state M _D > M _S is.

A similar Improvement of stability can be detected by the aforementioned "predictive" method with sensors, which measure other physical parameters can be achieved. Such For example, a sensor may be a lateral accelerator. An increased lateral acceleration would one increase indicating the destabilizing centrifugal force.

Another example is by the dashed lines in FIG 2 and 3 shown. A sensor 30 can change the steering position of the front wheels 16 by measuring the steering angle θ of the steering wheel 18 or by monitoring the position of some favorably positioned parts of the steering mechanism, which is connected to the front wheels 16 connected, monitor.

One increased Steering angle becomes higher Turn the vehicle lead. A vehicle response function the steering angle θ or the extension Δθ can be before be programmed into the controller. For example, the answer may be the rotational speed can be programmed as a function ω = ω (Δθ, T, V). The character and the coefficients of such functions can through Testing the vehicle based on a set of steering angle values and velocities and subsequent regression analysis, which is known in the art, are determined.

Further Improvements in stability can by additional Sensors for determining the inclination can be achieved. The lateral Inclination angle can be determined by means of a lateral inclination angle sensor can be measured and can also indirectly by evaluating the rotational speed sensor and the lateral acceleration are determined. The means of the rotational speed sensor calculated centrifugal acceleration can with the evaluations of the Transverse accelerator are compared to the component of gravitational acceleration to determine the accelerometer and thus the angle of inclination. The lateral tilt angle can also indirectly through the evaluations of the vertical and lateral accelerometer.

Similarly the "predictive" method of forecasting the future Use forward-tilt information to turn one's self deteriorating stability to predict when slow downs when looking downwards or inclines when accelerating quickly when tilting upwards. The forward tilt angle can by means of a front / rear inclination sensor be or can indirectly through the evaluations vertical and measured forward / backward accelerometer become. a forward tilt angle can be used in order to predict deteriorating stability fast slowing down during of turning. Thus, the controller can control the vehicle speed control to achieve acceleration or deceleration, the stability will ensure.

• – Daten, welche das Fahrzeug, wie es gebaut wurde, charakterisieren, wie Gewicht (Masse), Trägheitsmomente, CG Position, Spur, Achsabstand, Raddurchmesser, etc;
• – Daten, die den Benutzer und/oder die Tragfähigkeit charakterisieren, wie Gewicht, Trägheitsmomente, CG Position, etc.; und
• – andere Koeffizienten (Konstanten) verschiedener das Verhalten das Fahrzeugs beschreibender Funktionen und relevant zum Lösen der Bewegungsgleichungen.

The control according to the invention can be programmed with data of the equation of motion necessary for the calculation. The data may include, but the list is not limiting.

• Data characterizing the vehicle as it was built, such as weight (mass), moment of inertia, CG position, lane, wheelbase, wheel diameter, etc;
• Data characterizing the user and / or load capacity, such as weight, moments of inertia, CG position, etc .; and
• Other coefficients (constants) of various functions describing the behavior of the vehicle and relevant for solving the equations of motion.

alternative can all or some of these data in the controller in averaged and unchangeable shape being represented.

The previously described control system may also be used in other electrical Mechanical steering vehicles comprising three-wheeled vehicles, like all ground vehicles, go-karts, club cars passenger vehicles, electric motorized push- and drag-add-trolley systems, single front or rear-wheel drive for manual steering of wheelchairs, electric trolley drive systems, electric forklift for Trucks or hand-operated, electric kids cars, electric 3-wheeler Rickshaws, electric City vehicles, etc.

In 5 and 6 is a three-wheeled scooter 40 which ver ver the control system according to the invention turns, shown. The two rear wheels 42 be by a motor 14 powered and a single front wheel 46 is done manually by means of a Tiller 48 directed. The motor 14 drives the wheels 42 by means of a differential gear (not shown here), which allows the wheels to move at curves at different speeds.

The user is sitting on a seat 50 and steers the vehicle 40 by means of handles 44 on the Tiller 48 , Will the Tiller 48 turned, the user directly turns the front wheel 46 , the user controls the speed by means of a control arm 52 which is central to the Tiller 48 near the handles 44 is appropriate. The operating arm 52 actuates a sensor 54 which determined the path and how far the operating arm was moved. The further the operating arm 52 to the handles 48 is pressed, the faster the selected speed. To Nachvornefahren the left hand end of the actuating arm 52 in the direction of the adjoining handle 44 pressed and for the reverse direction of the right hand end. This arrangement may as well be arranged in reverse, or a single end lever may be used. The means of the operating arm 52 selected speed is sent to the controller 26 which the engine 14 controls, transmits.

In the case of a three-wheeled vehicle, the tilting axis is not parallel to the direction of movement as in 4 shown. This can be taken into account when changing the coefficients in the formula presented above. In addition, the forward acceleration has a component in the lateral stability.

electrical Vehicles using the control system according to the invention, can as well with an engine which has the front wheels or a single front wheel drives, like a 3-wheeler Scooter in which the front wheel is driven by the engine, are driven. In this case, both the drive and the steering applied to the front wheel.

The Control system and method described above may further in other types of electric vehicles are applied at the steering is not directly by the user but indirectly via the same control system running becomes. A steering command can by the user by means of an electric Command unit, such as a joystick or a steering wheel, whose position is measured by means of a sensor or by other means, sent.

In 7 . 8th and 9 is a powered wheelchair 60 shown what a rack 62 , a seat 64 , a freely pivoting roller assembly 66 and transport wheels 68 . 70 , each by means of its own electric drive 72 . 74 are driven. The drives are controlled by a controller 76 , which incorporates the method according to the invention, controlled and have a user command device 78 , The command device 78 is shown in the form of a joystick, but may also include, among other configurations, a head movement sensor or a "tiller" sensor.

The command device 78 allows the user to select the speed and turn commands and those of the controller 76 via an electrical cable or via wireless data transmissions, such as radio, ultrasound, IR, etc. to transmit. The command device 78 may also be part of the controller 76 be. As in the previous example, the wheelchair control system may include a maneuver responsive sensor, such as an angular rate sensor 32 , exhibit.

The control 76 Can the left and right electric drive 72 . 74 steer separately to each wheel 68 . 70 independently forward, backward or able to stop. By controlling the left and right wheels so that each can be moved individually at different speeds or even in different directions, the controller can 76 reach that powered wheelchair 60 is moved with the selected forward and reverse speed and the selected rotation angle The user sits on a seat 64 and gives speed and turn commands to the controller 76 by means of the command device 78 ,

By using the speed and rotation commands, as well as the measurements and calculations described above (but with different speeds for each individual wheel), the controller can 76 Predicting and predicting the behavior of the vehicle As described above, when a critical predetermined state is detected, the controller will no longer execute the user's commands, but in this case, the control will be 76 not only impose a "safe speed" on the electric drive, but also a "safe angle of rotation" (or rotational speed). This ability to control both linear velocity and angle of rotation can be used to optimize control, for example, by imposition of an additional condition, like a substantially even speed decrease.

Another type of electric vehicle with an electric steering is in 10 and 11 shown. A four-wheeled car 80 is an example is an example of an electrically powered vehicle with an electro-mechanical steering. The car 80 has two rear wheels 82 , which by means of a motor drive 14 are driven ( 11 ) and two front wheels 86 , which by means of a servo drive 88 can be electrically controlled. A mechanical steering wheel 89 with a steering wheel angle sensor 90 is with a controller 96 , which includes the method according to the invention, connected. Similar to the vehicles in 1 and 2 has the vehicle 80 a spring-loaded pedal 22 with a sensor 24 which also with the controller 96 connected to the speed control.

The control 96 controls the servo drive 88 and the motor drive 14 according to the selected steering angle and the selected speed command, respectively by the user via the sensors 90 and 24 be set. The safe control method is similar to the example of the powered wheelchair 60 executed.

at all the different versions the user can control the controller the previously determined critical condition or the non-execution of the Speed or steering command by lighting a Warning lights, a voice signal or in another way be informed. this makes possible to change the commands entered by the user to the controller. moreover a safe steering angle can be calculated in real time and one User during of the company in dependence displayed by the current vehicle speed (for Example by means of an arrangement of LEDs).

wobei

m

– Masse des Fahrzeuges und der Passagiere an ihrem Schwerpunkt;

g

– Erdbeschleunigung;

aL

– seitliche Beschleunigung;

a

– seitlicher Neigungswinkel;

L₁

– Spur

L₂

– Schwerpunktshöhe über dem horizontalen Boden

Although a description of specific embodiments has been shown, it should be understood that various changes that are also within the scope of the present invention may be anticipated. For example, the system according to the invention can be simplified by not including the linear velocity V in the control variables. Such a system can only use lateral acceleration measurements (in this case, the lateral acceleration is the stability criterion or the factor that determines the stability criterion) and predict the lateral acceleration. As in 12 is shown to be a critical predetermined state in such a case when the destabilizing moment M _D over the outer wheel is greater than the stabilizing gravity moment M _S :

in which

m

- mass of the vehicle and passengers at their center of gravity;

G

- acceleration of gravity;

aL

Lateral acceleration;

a

- lateral inclination angle;

L ₁

- Track

L ₂

- Center of gravity above the horizontal ground

Claims (13)

Device for controlling an electrical Drive system of a motorized vehicle, comprising: one Sensor for monitoring a motion characteristic and a stability criterion of a vehicle; and a sensor for detecting a change in the movement characteristic of the vehicle; characterized by one in communication with the sensor standing computer-aided Control, the computer-aided Control, if the stability criterion and the change in the movement characteristic over according to predefined values, a change in the speed of the vehicle causes, so the stability criterion no longer above that previously set value. Device according to claim 1, characterized in that that the computer-aided Control is capable of to reduce the speed of the vehicle. Device according to claim 1, characterized in that that the computer-aided Control is capable of to change the direction of the vehicle. Device according to claim 1, characterized in that that one of the sensors of the computerized control system is a vehicle speed command to disposal provides a desired To reach vehicle speed. Apparatus according to claim 3, comprising a steering system and characterized in that the computer-aided control an at least Having indirectly associated with the steering system steering control. Device according to claim 1, characterized in that that the computer-aided Control periodically data which is characteristic for at least one of the maneuvers of the vehicle and the external conditions are, stores the data so that current data and at least one the previously obtained data are available, one with help the current data and the last data expected stability state of the vehicle and time-dependent Equations of motion for the vehicle calculates the determined condition with a previous one safety criterion, and, if that was the case before specified safety criterion is not met, a change the speed of the vehicle is effected so that the before specified safety criterion is met. Device according to claim 1, characterized in that that the motion characteristic includes speed. Device according to claim 1, characterized in that the motion characteristic comprises lateral acceleration. Device according to claim 7, characterized in that the motion characteristic comprises angular acceleration. Device according to claim 6, characterized in that that the data has at least one lateral inclination angle of the soil, a forward inclined angle of the ground, a vehicle speed and / or include a vehicle rotational speed. Device according to claim 5, characterized in that that the steering system is a mechanical steering system which is operational State is characterized by a steering parameter θ, where the steering control represents a change Δθ of the steering parameter θ. Device for controlling a motorized vehicle, full: a sensor for monitoring a movement characteristic and a stability criterion a vehicle; and a sensor for detecting a change in the motion characteristic of the vehicle; marked by, a computerized controller associated with the sensor, the computer-aided Control displays to a driver of the vehicle if the stability criterion and the change in the movement characteristic over the predetermined value, so that the driver measures to Stabilization of the vehicle can take. Device according to claim 12, characterized in that that the computer-aided Control at least one optical signal, an acoustic signal and / or a vibration signal for the driver has.