CA2128301A1 - Traction control system for an articulated work vehicle - Google Patents
Traction control system for an articulated work vehicleInfo
- Publication number
- CA2128301A1 CA2128301A1 CA 2128301 CA2128301A CA2128301A1 CA 2128301 A1 CA2128301 A1 CA 2128301A1 CA 2128301 CA2128301 CA 2128301 CA 2128301 A CA2128301 A CA 2128301A CA 2128301 A1 CA2128301 A1 CA 2128301A1
- Authority
- CA
- Canada
- Prior art keywords
- wheels
- electronic controller
- work vehicle
- speed
- wheel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
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
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
- B60T8/48—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition connecting the brake actuator to an alternative or additional source of fluid pressure, e.g. traction control systems
- B60T8/4809—Traction control, stability control, using both the wheel brakes and other automatic braking systems
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Regulating Braking Force (AREA)
- Operation Control Of Excavators (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A traction control system for an articulated work vehicle. The vehicle is provided with a front portion having a pair of front wheels and a rear portion having a pair of rear wheels. Each of the wheels is provided with an independently operated brake and a speed sensor for sensing the speed of the respective wheel. The speed signals are directed to an electronic controller that brakes selected wheels when they are slipping relative to the other wheels.
An articulation angle compensation factor is used modify the calculatlon of wheel slip and braking power.
A traction control system for an articulated work vehicle. The vehicle is provided with a front portion having a pair of front wheels and a rear portion having a pair of rear wheels. Each of the wheels is provided with an independently operated brake and a speed sensor for sensing the speed of the respective wheel. The speed signals are directed to an electronic controller that brakes selected wheels when they are slipping relative to the other wheels.
An articulation angle compensation factor is used modify the calculatlon of wheel slip and braking power.
Description
212~
A TRACTION CONTROL S~STEM FOR AN ARTICULATED WORK VEHICL~
BACKGROUND OF THE INVENTION
l~ Field of the Invention:
The invention is directed ~o a traction control sy~tem for an articulated work vehicle.
A TRACTION CONTROL S~STEM FOR AN ARTICULATED WORK VEHICL~
BACKGROUND OF THE INVENTION
l~ Field of the Invention:
The invention is directed ~o a traction control sy~tem for an articulated work vehicle.
2. Description of the Prior Art:
To reduce steering radius and increase maneuverability large work vehicles, such as four wheel dr~ve loaders and four wheel drive agricultural tractors, are articulated about a vertical axis located between the front and rear wheels.
These vehicles are typically off road vehicles and work in poor traction conditions. They are provided with four wheel drive to increase traction. In addition they may be provided with limited slip differentials or differential locks to provide additional traction in especially poor conditions.
A conventional automobile is a rigid frame vehicle which is steered by an axle that is pivotable about a vertical axis.
Typically, the steering axle is the front axle. Traction control system~ have besn proposed for automobiles which use selective and independent braking of wheels to improve and/or maintain traction.
U.S. Patent 5,205,622 discloses a traction control system.
SUMMARY
It is the main object of the present invention to provide an automatic system for increasing traction in an articulated work vehicle, when it is operating in poor traction conditions.
It is a feature of the present invention that an eiectronic controller controls that application of braking pressure to a slipping wheel.
It is another feature of the pre~ent invention that the service brake for each wheel can be independently controlled by the electronic controller.
, In operation the electronic controller senses the speed ¦ of all four wheels and the articulation angle of the vehicle.
~he controller calculates a front wheel target speed from the average speed of the front wheels, and a rear wheel target 212~301 ~peed from the average speed of the rear wheels. A ~, compensation factor is derived from the articulation angle of the vehicle. The compensation factor compensates for the steering angle of the vehicle and is used in calcualting ~lip.
If the front wheel slip or the rear wheel slip is less than or equal to .85 or greater than or equal to 1.15, the electronic controller applies braking force to the appropri~te slipping wheel. The braking force is applied in proportion to the actual wheel slip plus the braking power applied in the last cycle less a decay factor.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side view of a four wheel drive loader.
Figure 2 is a hydraulic and electrical schematic of a first embodiment of the traction control system.
Figure 3 is a hydraulic and electrical schematic of a second embodiment of the traction control system.
Figures 4a through 4c are flow chart~ on how the traction control system operates.
DETAILED DESCRIPTION
Figure 1 is a side view of a four wheel drive articulated loader 10. Load~r 10 comprises a supporting structure 12 and ground engaging wheels 14. The front o~ th(Q loader is provided with a moveable boom assembly 16 at: the end of which is a pivotally mounted bucket 18. The boom is lifted by extending boom lift hydraulic actuator 20, and the bucket is pivoted by bucket tilt hydraulic actuator 22.
The loader is ~rticulated about vertical pivots 24 and 26 by a hydraulic steering circuit disclo~ed in U.S. Patent 4,898,0~8 which i~ incorporated herein by reference. The loader i~ driven by an internal combustion engine 28 that i~
housed in engine compartment 30. The internal combustion engine drives a transmission 32 for propalling the loader and a hydraulic pump 34 for operating various vehicle function6 such as the hydraulically operated brake~. The operator controls the operation of the loader from cab 36.
Figure 2 is directed to a first embodiment of the traction control system on loader 10. Hydraulic pump 34 "~
- 21233~1 airects pressurized hydraulic fluid into supply/return line 38. This pressurized hydraulic fluid is directed to left front service brake 40 and right front service brake 42, by a left pedal valve 44. Similarly, pressurized hydraulic fluid is applied to left rear service brake 46 and right rear servi~e brake 48, by right pedal valve 50. A hydraulic accumulator 52 is used to provide reserve ~lydraulic pressure when the vehicle is turned off.
The left pedal valve 44 and the right pedal valve 50 each comprise two hydraulic valves that can independently apply pressure to either the left or right front service brakes 40 and 42, or the left and right rear service brakes 46 and 48, respectively. Therefore the operator can apply braking force to either the front wheels or the rear wheels by selectively depressing pedal valves 44 and 50.
Each wheel is also provided with a speed sensor 54, 56, 58 or 60. Each of these speed sensors provide an electronic signal indicating the speed of the individual wheels. The vehicle is also provided with an articulated angle sensor 62 which provides an electronic signal as to the articulation angle of the vehicle.
The four speed sensor~ 54, 56, 58 and 60 and the articulation angle sensor 62 are electrica:~ly connected to an electronic controller 64. The electronic controller is electrically coupled to pressure reducing valves 66. The pressure reducing valves in turn are hydraulically coupled to brakes 40, 42, 44 and 46 by supply/return lines 41, 43, 45 and 47. The electronic controller in response to the signals from the speed sensors and the articulation angle sensor, Qignals the pressure reducing valves which selectively apply braking pressure to each of the brakes 42, 44, 46 and 48. The electronic controller is guided by a flow chart illustrated in Figures 4A through 4C.
A brake-by-wire embodiment is illustrated in Figure 3.
In figure 3 the same numbers have been used for identical elements as were used in Figure 2. In this embodimentO the left front brake valve 70, the right front brake valve 72, the .j 'I
,~ .
212~301 left rear brake valve 74 and the righ1: rear brake valve 76 are electro-hydraulic valves controlled directly by electronic controller 66. In addition, the operation of the service brakes is also fed through the electronic controller by foot brake pedal 80 contacting brake pedal position sensor 82.
The algorithm for controlling the traction control system is illustxated as a flow chart in Figures ~A through 4C. As shown in Figure 4A the first step, step 100 is to start the traction control system. In the second step 110~ the electronic controller initiates a 50 msec timeframe. At the third step, step 120 the electronic controller interrogates the articulation angle sensor 62 to determine the articulation angle (AA) of the vehicle. In step 130 the electronic controller interrogates the speed sensors 54, 56, 58 and 60 to determine the speeds of the individual wheels (LF, RF, LR &
RR) .
~ fter the electronic controller has determined these variables, it calculates an angle compensation factor (CF) at step 140 and a target speed (TS) at step 150. The angle compensation factor (CF) is calculated by the following equation:
CF= h--~ana h+~rrtan where h is the distance from the centerline of the axle to the articulation axis, m is half the track width and ~ is the articulation angle. ~he angle compensation factor is then 2S stored for later use. It should be noted that in most articulated vehicles the angl~ compensation factor would be identical for the front and rear wheels, however in some vehicles the distance (h) from the articulation axis to the center line of the front and rear axles may be different. In addition the track width (m) may ba different between the front and rear axles. In the present application the factors h and m are assumed to be constant for the front and rear axles. Thereby making the compensation factor the same for both axles.
- ~12~3~1 The front axle target speed is calculated from the speed of the left front wheel (LF) and the right front wheel (RF).
The electronic controller calculates the front axle target speed (TS) as being the average speed (TS=fLF+RF)/2) of the front wheels.
At step 160 the electronic controller checks for any previously set control or monitor mode flags. It should be noted that if no control mode flags are found the electronic controller defaults to the monitor mode routine illustrated in Figure 4b. If a control mode flag is found the program proceeds to the control mode routine, illustrated in Figure 4c.
After the performing the control mode routine or the monitor mode routine electronic controller performs the same operation on the rear wheels and axle,. More specifically, if necessary the electronic controller calculates a rear axle compensation factor and target speed. The electronic controller would then search for control or monitor mode flags to perform a monitor mode routine or a control mode routine for the rear wheels. For simplicity the rear wheel portion of the program have not been illustrated as they are substantially identical to the front wheel portion of the program that is illustrated.
The monitor mode routine is illustrated in Figure 4B. In step 210 the electronic controller first calculate the front wheel slip (~S~ by dividing the left front wheel speed (LF) by the right front wheel speed (RF) and multiplying the quotient by the compensation factor (CF).
At step 220 the electronic controller determines if the front slip i8 less then or equal to .85. If the front wheel 81ip i~ less than or equal to .85, the electronic controller is directed to steps to 230 and 240. If the front wheel slip i8 greater than .85 the electronic controller is directed to step 250. At step 230 the electronic controller stores the information that the right front wheel is slipping. At ~tep 240 a control mo*e flag is set. After completing step 240 the electronic controller is directed to step 170. After .
2 ~2,~301 ' completing step 170, the electronic controller returns to the start at step lO0.
At step 250 the electronic controller determines if the front wheel slip is greater than or equal to 1.15. If the front wheel slip is greater than or equal to 1.15, the electronic controller is directed to steps 260 and 270. If the front wheel slip is less than 1.15, the electronic controller is directed to step 170. At step 260 the electronic controller stores the information that the le~t front wheel is slipping. At ~tep 270 a control mode flag is set. A~ter completing step 270 the electronic controller is directed to step 170. After completing step 170, the electronic controller returns to the ctart at step 100.
The control mode routine is illustrated in Figure 4c.
The control mode routine i~ used to calculate the amount of braking power need to be applied to a selected slipping wheel.
In step 310 the electronic controller calculates the compensated speed (CS) for the individual slipping wheel by multiplying the compensation factor (CF) by the æpeed of the slipping wheel identified in the monitor mode routine. Next in step 320 the electronic controller calculates individual wheel 81ip (WS) by subtracting the compensated speed (CS) from the target speed (TS).
In step 330 the electronic controll~r calculates and applies braking power to the slipping wheeh. The amount of braking power (BPn) to be applied in the current cycle equals the amount of braking power (BP(n-1)) applied in the last cycle plu6 the individual wheel slip (WS) less a decay factor.
The decay factor is a constant actor. In step 340, the electronic controller determines if the current braking power (BPn) is less than or equal to zero. If the current braking power is less than or equal to zero, the electronic controller sets a monitor flag at step 350. After setting the ~lag in step 350, the electronic controller proceeds to step 173. If the current braking power is greater than zero, the electronic controller proceeds directly to step 170.
~ 212,~30?
After completing the rear axle routine at step 170, the electronic controller returns to the start at step 100. The electronic controller would update the data from the articulation angle and speed sensors and look for flags set by either the monitor mode routine or the control mode routine.
The present invention should not be limited by the above described embodiments, but should be limited solely by the claims that follow.
: ~ . . :- - :........... : : : :, .,,. . .:
. , : ~ . - .: :, - . - . . : : .", :;. . :, . . . -, :; .. . ; : ~ -, : - .
To reduce steering radius and increase maneuverability large work vehicles, such as four wheel dr~ve loaders and four wheel drive agricultural tractors, are articulated about a vertical axis located between the front and rear wheels.
These vehicles are typically off road vehicles and work in poor traction conditions. They are provided with four wheel drive to increase traction. In addition they may be provided with limited slip differentials or differential locks to provide additional traction in especially poor conditions.
A conventional automobile is a rigid frame vehicle which is steered by an axle that is pivotable about a vertical axis.
Typically, the steering axle is the front axle. Traction control system~ have besn proposed for automobiles which use selective and independent braking of wheels to improve and/or maintain traction.
U.S. Patent 5,205,622 discloses a traction control system.
SUMMARY
It is the main object of the present invention to provide an automatic system for increasing traction in an articulated work vehicle, when it is operating in poor traction conditions.
It is a feature of the present invention that an eiectronic controller controls that application of braking pressure to a slipping wheel.
It is another feature of the pre~ent invention that the service brake for each wheel can be independently controlled by the electronic controller.
, In operation the electronic controller senses the speed ¦ of all four wheels and the articulation angle of the vehicle.
~he controller calculates a front wheel target speed from the average speed of the front wheels, and a rear wheel target 212~301 ~peed from the average speed of the rear wheels. A ~, compensation factor is derived from the articulation angle of the vehicle. The compensation factor compensates for the steering angle of the vehicle and is used in calcualting ~lip.
If the front wheel slip or the rear wheel slip is less than or equal to .85 or greater than or equal to 1.15, the electronic controller applies braking force to the appropri~te slipping wheel. The braking force is applied in proportion to the actual wheel slip plus the braking power applied in the last cycle less a decay factor.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side view of a four wheel drive loader.
Figure 2 is a hydraulic and electrical schematic of a first embodiment of the traction control system.
Figure 3 is a hydraulic and electrical schematic of a second embodiment of the traction control system.
Figures 4a through 4c are flow chart~ on how the traction control system operates.
DETAILED DESCRIPTION
Figure 1 is a side view of a four wheel drive articulated loader 10. Load~r 10 comprises a supporting structure 12 and ground engaging wheels 14. The front o~ th(Q loader is provided with a moveable boom assembly 16 at: the end of which is a pivotally mounted bucket 18. The boom is lifted by extending boom lift hydraulic actuator 20, and the bucket is pivoted by bucket tilt hydraulic actuator 22.
The loader is ~rticulated about vertical pivots 24 and 26 by a hydraulic steering circuit disclo~ed in U.S. Patent 4,898,0~8 which i~ incorporated herein by reference. The loader i~ driven by an internal combustion engine 28 that i~
housed in engine compartment 30. The internal combustion engine drives a transmission 32 for propalling the loader and a hydraulic pump 34 for operating various vehicle function6 such as the hydraulically operated brake~. The operator controls the operation of the loader from cab 36.
Figure 2 is directed to a first embodiment of the traction control system on loader 10. Hydraulic pump 34 "~
- 21233~1 airects pressurized hydraulic fluid into supply/return line 38. This pressurized hydraulic fluid is directed to left front service brake 40 and right front service brake 42, by a left pedal valve 44. Similarly, pressurized hydraulic fluid is applied to left rear service brake 46 and right rear servi~e brake 48, by right pedal valve 50. A hydraulic accumulator 52 is used to provide reserve ~lydraulic pressure when the vehicle is turned off.
The left pedal valve 44 and the right pedal valve 50 each comprise two hydraulic valves that can independently apply pressure to either the left or right front service brakes 40 and 42, or the left and right rear service brakes 46 and 48, respectively. Therefore the operator can apply braking force to either the front wheels or the rear wheels by selectively depressing pedal valves 44 and 50.
Each wheel is also provided with a speed sensor 54, 56, 58 or 60. Each of these speed sensors provide an electronic signal indicating the speed of the individual wheels. The vehicle is also provided with an articulated angle sensor 62 which provides an electronic signal as to the articulation angle of the vehicle.
The four speed sensor~ 54, 56, 58 and 60 and the articulation angle sensor 62 are electrica:~ly connected to an electronic controller 64. The electronic controller is electrically coupled to pressure reducing valves 66. The pressure reducing valves in turn are hydraulically coupled to brakes 40, 42, 44 and 46 by supply/return lines 41, 43, 45 and 47. The electronic controller in response to the signals from the speed sensors and the articulation angle sensor, Qignals the pressure reducing valves which selectively apply braking pressure to each of the brakes 42, 44, 46 and 48. The electronic controller is guided by a flow chart illustrated in Figures 4A through 4C.
A brake-by-wire embodiment is illustrated in Figure 3.
In figure 3 the same numbers have been used for identical elements as were used in Figure 2. In this embodimentO the left front brake valve 70, the right front brake valve 72, the .j 'I
,~ .
212~301 left rear brake valve 74 and the righ1: rear brake valve 76 are electro-hydraulic valves controlled directly by electronic controller 66. In addition, the operation of the service brakes is also fed through the electronic controller by foot brake pedal 80 contacting brake pedal position sensor 82.
The algorithm for controlling the traction control system is illustxated as a flow chart in Figures ~A through 4C. As shown in Figure 4A the first step, step 100 is to start the traction control system. In the second step 110~ the electronic controller initiates a 50 msec timeframe. At the third step, step 120 the electronic controller interrogates the articulation angle sensor 62 to determine the articulation angle (AA) of the vehicle. In step 130 the electronic controller interrogates the speed sensors 54, 56, 58 and 60 to determine the speeds of the individual wheels (LF, RF, LR &
RR) .
~ fter the electronic controller has determined these variables, it calculates an angle compensation factor (CF) at step 140 and a target speed (TS) at step 150. The angle compensation factor (CF) is calculated by the following equation:
CF= h--~ana h+~rrtan where h is the distance from the centerline of the axle to the articulation axis, m is half the track width and ~ is the articulation angle. ~he angle compensation factor is then 2S stored for later use. It should be noted that in most articulated vehicles the angl~ compensation factor would be identical for the front and rear wheels, however in some vehicles the distance (h) from the articulation axis to the center line of the front and rear axles may be different. In addition the track width (m) may ba different between the front and rear axles. In the present application the factors h and m are assumed to be constant for the front and rear axles. Thereby making the compensation factor the same for both axles.
- ~12~3~1 The front axle target speed is calculated from the speed of the left front wheel (LF) and the right front wheel (RF).
The electronic controller calculates the front axle target speed (TS) as being the average speed (TS=fLF+RF)/2) of the front wheels.
At step 160 the electronic controller checks for any previously set control or monitor mode flags. It should be noted that if no control mode flags are found the electronic controller defaults to the monitor mode routine illustrated in Figure 4b. If a control mode flag is found the program proceeds to the control mode routine, illustrated in Figure 4c.
After the performing the control mode routine or the monitor mode routine electronic controller performs the same operation on the rear wheels and axle,. More specifically, if necessary the electronic controller calculates a rear axle compensation factor and target speed. The electronic controller would then search for control or monitor mode flags to perform a monitor mode routine or a control mode routine for the rear wheels. For simplicity the rear wheel portion of the program have not been illustrated as they are substantially identical to the front wheel portion of the program that is illustrated.
The monitor mode routine is illustrated in Figure 4B. In step 210 the electronic controller first calculate the front wheel slip (~S~ by dividing the left front wheel speed (LF) by the right front wheel speed (RF) and multiplying the quotient by the compensation factor (CF).
At step 220 the electronic controller determines if the front slip i8 less then or equal to .85. If the front wheel 81ip i~ less than or equal to .85, the electronic controller is directed to steps to 230 and 240. If the front wheel slip i8 greater than .85 the electronic controller is directed to step 250. At step 230 the electronic controller stores the information that the right front wheel is slipping. At ~tep 240 a control mo*e flag is set. After completing step 240 the electronic controller is directed to step 170. After .
2 ~2,~301 ' completing step 170, the electronic controller returns to the start at step lO0.
At step 250 the electronic controller determines if the front wheel slip is greater than or equal to 1.15. If the front wheel slip is greater than or equal to 1.15, the electronic controller is directed to steps 260 and 270. If the front wheel slip is less than 1.15, the electronic controller is directed to step 170. At step 260 the electronic controller stores the information that the le~t front wheel is slipping. At ~tep 270 a control mode flag is set. A~ter completing step 270 the electronic controller is directed to step 170. After completing step 170, the electronic controller returns to the ctart at step 100.
The control mode routine is illustrated in Figure 4c.
The control mode routine i~ used to calculate the amount of braking power need to be applied to a selected slipping wheel.
In step 310 the electronic controller calculates the compensated speed (CS) for the individual slipping wheel by multiplying the compensation factor (CF) by the æpeed of the slipping wheel identified in the monitor mode routine. Next in step 320 the electronic controller calculates individual wheel 81ip (WS) by subtracting the compensated speed (CS) from the target speed (TS).
In step 330 the electronic controll~r calculates and applies braking power to the slipping wheeh. The amount of braking power (BPn) to be applied in the current cycle equals the amount of braking power (BP(n-1)) applied in the last cycle plu6 the individual wheel slip (WS) less a decay factor.
The decay factor is a constant actor. In step 340, the electronic controller determines if the current braking power (BPn) is less than or equal to zero. If the current braking power is less than or equal to zero, the electronic controller sets a monitor flag at step 350. After setting the ~lag in step 350, the electronic controller proceeds to step 173. If the current braking power is greater than zero, the electronic controller proceeds directly to step 170.
~ 212,~30?
After completing the rear axle routine at step 170, the electronic controller returns to the start at step 100. The electronic controller would update the data from the articulation angle and speed sensors and look for flags set by either the monitor mode routine or the control mode routine.
The present invention should not be limited by the above described embodiments, but should be limited solely by the claims that follow.
: ~ . . :- - :........... : : : :, .,,. . .:
. , : ~ . - .: :, - . - . . : : .", :;. . :, . . . -, :; .. . ; : ~ -, : - .
Claims (4)
1. A work vehicle for performing a work operation, the work vehicle comprising:
a supporting structure having a front portion and a rear portion, the front and rear portions can be articulated relative to one another about a vertical axis;
left and right front wheels mounted to the front portion of the supporting structure;
left and right rear wheels mounted to the rear portion of the supporting structure;
four independently operated brakes, one brake is associated with each of the four wheels; and a controller for automatically applying the brakes independently to the wheels slipping relative to the other wheels.
a supporting structure having a front portion and a rear portion, the front and rear portions can be articulated relative to one another about a vertical axis;
left and right front wheels mounted to the front portion of the supporting structure;
left and right rear wheels mounted to the rear portion of the supporting structure;
four independently operated brakes, one brake is associated with each of the four wheels; and a controller for automatically applying the brakes independently to the wheels slipping relative to the other wheels.
2. A work vehicle as defined by claim 1 wherein each of the wheels is provided with a speed sensor that signals the controller as to the speed of the respective wheel.
3. A work vehicle as defined by claim 2 further comprising an articulation angle sensor for sensing how much the front portion and the rear portion of the supporting structure are articulated relative to one another and signalling this to the controller.
4. A work vehicle as defined by claim 3 wherein the controller uses the signal from the articulation angle sensor to calculate a compensation factor to determine if brakes should be applied to an individual wheel and how much braking force should be applied to an individual wheel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US12894693A | 1993-09-29 | 1993-09-29 | |
| US08/128,946 | 1993-09-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2128301A1 true CA2128301A1 (en) | 1995-03-30 |
Family
ID=22437751
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2128301 Abandoned CA2128301A1 (en) | 1993-09-29 | 1994-07-18 | Traction control system for an articulated work vehicle |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0646509A1 (en) |
| JP (1) | JPH07149221A (en) |
| CA (1) | CA2128301A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19956469A1 (en) | 1999-11-24 | 2001-05-31 | Mannesmann Rexroth Ag | Hydrostatic propulsive drive has braking device that interacts with each motor connected to control unit that activates brake if its associated motor's speed exceeds predetermined threshold |
| JP2004525017A (en) * | 2000-12-20 | 2004-08-19 | キャタピラー インコーポレイテッド | Construction machine with traction control device |
| GB2439333A (en) * | 2006-06-20 | 2007-12-27 | Bamford Excavators Ltd | Loading machine with ABS |
| EP4379149A1 (en) * | 2022-03-24 | 2024-06-05 | Hitachi Construction Machinery Co., Ltd. | Control device for wheel loader |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4423785A (en) * | 1980-03-18 | 1984-01-03 | Kabushiki Kaisha Komatsu Seisakusho | Load control device for a working tool of a construction vehicle |
| AT385538B (en) * | 1986-04-04 | 1988-04-11 | Voest Alpine Ag | DEVICE FOR SECURING MOVABLE CHARGERS |
| US4898078A (en) * | 1987-09-11 | 1990-02-06 | Deere & Company | Hydraulic system for a work vehicle |
| US4926333A (en) * | 1988-04-20 | 1990-05-15 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Traction control apparatus |
| WO1990014472A1 (en) * | 1989-05-17 | 1990-11-29 | M & H Blanch Pty Limited | Independent drive controls for skid steer loader |
| US5205622A (en) * | 1991-02-08 | 1993-04-27 | Eaton Corporation | Vehicular traction control system |
-
1994
- 1994-07-18 CA CA 2128301 patent/CA2128301A1/en not_active Abandoned
- 1994-09-28 EP EP94115296A patent/EP0646509A1/en not_active Withdrawn
- 1994-09-29 JP JP23542894A patent/JPH07149221A/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| EP0646509A1 (en) | 1995-04-05 |
| JPH07149221A (en) | 1995-06-13 |
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