Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/17—Using electrical or electronic regulation means to control braking
  • B60T8/175—Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/17—Using electrical or electronic regulation means to control braking
  • B60T8/172—Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T2210/00—Detection or estimation of road or environment conditions; Detection or estimation of road shapes
  • B60T2210/10—Detection or estimation of road conditions
  • B60T2210/14—Rough roads, bad roads, gravel roads

Definitions

• the invention relates to a method and a circuit arrangement for vehicle control, in which the rotational behavior of the individual wheels is measured and for determining the vehicle reference speed, the
• Wheel slip the wheel acceleration and other controlled variables is evaluated. These variables are used to measure and / or modulate the brake pressure in the wheel brakes of the controlled wheels and / or to intervene in the engine management.
• ABS anti-lock braking systems
• ABS Traction control system
• ESP vehicle dynamics control
• EDS Differential lock
• ASR throttles engine torque by intervening in engine management to keep the load on the brakes as low as possible.
• ASR means all conceivable traction control systems, i.e. those with and without intervention in engine management.
• the vehicle control systems are basically designed for use on the road characterized by largely flat ground and at least approximately the same coefficient of friction on some sides.
• a particular problem with vehicle control is a driving situation on a gravel road or a similar road with an increased slip requirement.
• the object of the invention is therefore to provide a method and a circuit arrangement for recognizing a gravel road or a similar road with an increased need for slip.
• the object is achieved according to the invention by a method, which is characterized in that the vibration behavior of the individual wheels on the driven axle is detected and evaluated in order to identify a gravel road or a similar roadway with an increased need for slip, and that the driving situation of a road road then is regarded as is recognized and / or a corresponding control function of the vehicle control is only activated if the wheel acceleration on at least two wheels exceeds a predetermined wheel loading limit value and if the at least two wheels e have certain vibration behavior.
• the term “increased slip requirement” in the sense of the invention meaning that the longitudinal force (force in the circumferential direction of the tire for transmitting the driving forces and in the case of a braking operation of the braking forces) reaches its maximum at higher wheel slip
• the slip requirement of a gravel roadway is even higher than the slip requirement for stuck snow.
• the driving situation of a gravel road is then recognized and / or a corresponding control function of the vehicle control is only activated if the wheel acceleration is greater than the predetermined limit value and if the wheels have a certain vibration behavior. That means if certain vibration conditions are met that are characteristic of a gravel road.
• a value in a range from 1 g to 2 g, in particular approximately 1.5, is preferably specified as the wheel-loading limit value.
• a prerequisite for the detection of a gravel road is the detection of a predetermined period of the vibrations on at least two driven wheels which are within a predetermined period, preferably within a range of 30 msec. up to 150 msec, or the detection of a predetermined period of the vibrations on at least two driven wheels, which reaches a predetermined limit value, preferably approximately 50 msec.
• the period of the vibrations is advantageously recorded over a certain period of time in order to reliably recognize a period.
• the period is preferably 30 msec. up to 150 msec, in particular approx. 50 msec. That means, in general, the detection of an oscillation period is sufficient for the detection of a gravel road.
• Gravel road is then recognized and / or a corresponding control function of the vehicle control is only activated when the driven wheels have a predetermined traction slip, in particular a traction slip in a range from 0 km / h to 50 km / h.
• a gravel roadway is recognized and / or a corresponding control function of the vehicle control is only activated in the method if the calculated or estimated vehicle reference speed falls below a predetermined vehicle speed limit value, which is advantageously in a range from 60 km / h to 100 km / h and is preferably about 80 km / h.
• a gravel road is then recognized and / or a corresponding control function of the vehicle control is only activated if the above-mentioned conditions for a gravel road for the two wheels of a vehicle side and / or a vehicle axle have been recognized in a vehicle with all-wheel drive or if in a vehicle with a driven axle for both wheels of the driven axle, the aforementioned conditions for a gravel road conditions were recognized.
• the term “vehicles with all-wheel drive” encompasses both vehicles with permanently at least four driven wheels on at least two driven axles, and primarily vehicles driven with one axle, in which a second axle can be additionally activated if necessary. This can be done manually or automatically, for example using a viscous coupling.
• an engine control threshold is increased according to the invention to preferably a value in a range from 2 km / h to 10 km / h, particularly preferably approximately 3 km / h, and / or one Brake control threshold is increased, preferably to a predetermined value in a range from 0 km / h to 10 km / h, particularly advantageously approximately 3 km / h.
• engine control threshold here means the wheel slip to be set by the engine control, in particular TCS engine controller, in order to achieve the best possible compromise between traction and driving stability.
• brake control threshold is used to achieve the best possible compromise between traction and driving stability wheel slip to be set by the brake controller, in particular TCS brake controller.
• the brake control threshold is raised only when certain driving situations are detected, for example, overturning wheels, for example off-road in the event of large wheel load fluctuations or o-split conditions.
• vehicle control such as anti-lock braking system (ABS), traction control (ASR) or vehicle dynamics control (ESP), which is characterized in that it is used to detect a
• a gravel road or a similar roadway with an increased need for slip has a detection circuit which is assigned a detection circuit for detecting the vibration behavior of the individual wheels, the output of which is connected to an input of an evaluation circuit for evaluating the detected vibration behavior, and which detection circuit has an integrator and a signal generator , to generate a signal when, with the help of the evaluation by the evaluation circuit, a vibration behavior of the wheels, which is determined for a gravel road and is determined by the integrator, is detected.
• the detection circuit preferably has comparators for the wheel acceleration and extreme value detectors in order to detect the vibration behavior of the individual wheels.
• the circuit arrangement is characterized in that the
• Detection circuit is assigned a detection circuit for determining a
• Vehicle reference speed based on measured values, the output of which is connected to an input of a first comparator, which is used to determine the determined
• Wheel loading limit value for comparing the vibration behavior of the individual wheels with each other, and a fourth comparator for comparing the traction slip of the wheels with a predetermined limit value, and that the signal generator is connected via an output to an input with a device with which Help with an appropriate signal for the recognized driving situation of a gravel roadway an intervention in the brake control and / or engine control can be undertaken.
• FIG. 1 shows a flowchart of an embodiment of the method according to the invention for detecting the wheel vibration behavior for a gravel road on a wheel.
• FIG. 2 shows a flow diagram of an embodiment of the method for detecting a gravel road according to the invention.
• FIG. 3 shows a block diagram of an embodiment of the circuit arrangement for detecting a gravel road according to the invention.
• query 2 calls for a wheel acceleration that is above a wheel loading limit value (B l ⁇ m ), for example above 1 g. Then the vibration behavior of the individual wheels is checked for a specific vibration behavior characteristic of a gravel road. To do this - at one
• Exceeding the wheel loading limit value (B l ⁇ m ) - the time period between the maxima of an oscillation period is determined and m the query steps 3 and 4 check whether the period of the vibrations on the wheel is within a predetermined period duration range, which is determined by an upper limit value (Ti ) (Step 3) and a lower limit (T) (Step 4) is defined.
• the interval defined by the upper limit value (T x ) and lower limit value (T) is determined in dependence on the dynamics and the vibration behavior of the drive train of the vehicle and the driving spell to be detected. If these conditions are met, an integrator m assigned to the wheel in question is incremented in a predetermined period of time.
• a payer assigned to the wheel in question is increased by 1 in a step 5. If this is not the case, in step 6 the payer is decreased by 1 in each case. The value can be decremented down to zero (0). On the other hand, if the payer exceeds a threshold value (PAYER l ⁇ m ) (step 7), the conditions for the wheel concerned are one
• step 8 Gravel road detected. Otherwise, if the conditions of steps 2 or 3 or 4 or 7 are not the vibration conditions for a ballast track on the wheel are not recognized (step 9).
• step 8 or 9 the driving situation of a gravel road is advantageously determined according to the flow chart shown in Fig. 2 (initial step 10).
• the determined vibration behavior of the individual wheels is compared with each other.
• a predetermined range ie below a first limit value (Si), for example 50 km / h (step 12) and above a second limit value (p 2 ), for example 0 km / h (step 13)
• the query proceeds to step 14.
• step 14 it is asked whether the
• Vehicle reference speed (V ref ) is below a speed threshold (V l ⁇ m ), for example below 80 km / h. If this is the case, the driving situation of a gravel road is considered to be recorded and a corresponding control function of the vehicle control can take place. This can, for example, increase the engine control threshold and / or the
• Brake control threshold step 15
• the main program of the control returns, for example an ASR control (step 16).
• ASR traction control system
• FIG. 3 shows the block diagram of a circuit arrangement which shows, by way of example, the essential electrical / electronic components of an embodiment for detecting a gravel road.
• the detection circuit (20) is essential for the invention.
• the detection circuit (20) is a detection circuit (21) for detecting the
• Vibration behavior assigned to the individual wheels the output (22) of which is connected to an input (23) of an evaluation circuit (24) for evaluating the detected vibration behavior.
• Detection circuit (20) has an integrator (25) and a signal generator (26) for generating a signal, if with the help of the evaluation by the
• the detection circuit (20) is also assigned a determination circuit (27) for determining a vehicle reference speed (V ref ) on the basis of measured values.
• An output (28) of the determination circuit (27) is connected to an input (29) of a first comparator (30) which serves to determine the determined vehicle reference speed (V ref ) with a compare the predetermined limit value (V l ⁇ m ) and which first comparator (30) is connected via an output (31) to an input (32) of the evaluation circuit (23) which compares the detected vibration behavior of the individual wheels, in particular the period of a vibration with predetermined limit values (T ⁇ , T).
• the detection circuit (20) has a second comparator (33) for comparing the wheel acceleration with a wheel application limit value (B l ⁇ m ), a third comparator (34) for comparing the vibration behavior of the individual wheels with each other, and a fourth comparator (35) for comparing of the drive slip of the wheels with a predetermined limit (S ⁇ , S).
• the signal generator (26) is connected via an output (36) to an input (37) of a device (38), with the aid of which an intervention in the brake control and / or engine control can be carried out with a corresponding signal for the recognized driving situation of a gravel road.

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• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Regulating Braking Force (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)

Priority Applications (3)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26005454

Family Applications (1)

Country Status (4)

Cited By (1)

Citations (5)

• 2000
  • 2000-07-20 DE DE50014677T patent/DE50014677D1/de not_active Expired - Lifetime
  • 2000-07-20 JP JP2001512411A patent/JP2003505293A/ja not_active Withdrawn
  • 2000-07-20 WO PCT/EP2000/006955 patent/WO2001007306A1/de not_active Ceased
  • 2000-07-20 EP EP00951412A patent/EP1202889B1/de not_active Expired - Lifetime

Patent Citations (5)

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