WO2018236298A1

WO2018236298A1 - Control system and method for agricultural tractors

Info

Publication number: WO2018236298A1
Application number: PCT/TR2017/050286
Authority: WO
Inventors: Ertunç Enveroğlu; Samet Adem Cömert; Ender INCE
Original assignee: Türk Traktör Ve Zi̇raat Maki̇neleri̇ A.Ş.
Priority date: 2017-06-23
Filing date: 2017-06-23
Publication date: 2018-12-27

Abstract

The control system (30) is described which has a control unit (31) and various types of sensors which are integrated to tractor (10) and connected to the control unit (31), to control operating conditions of the tractor (10) according to parameters defined by an operator.

Description

CONTROL SYSTEM AND METHOD FOR AGRICULTURAL TRACTORS FIELD OF INVENTION

The present invention relates to control system and method for controlling earthmoving vehicle, in particularly agricultural tractors, equipped with a Continuously Variable Transmission (CVT) and various types of sensors.

PRIOR ART

Conventional agricultural tractors have a three-point linkage mechanism to attach implements. Three point linkages most frequently consist of two lower lifting arms to which an implement is attached. The lower lifting arms can be pivoted by respective hydraulic actuating cylinders to adjust the height position of the implement relative to the agricultural tractor. Furthermore, these lower lifting arms may be manually adjusted by length to be appropriate for an implement to be attached. An additional top link connects the implement to the agricultural tractor above the lower lifting arms. This top link is used to pivot the implement about a horizontal transverse axis and is adjustable by means of a threaded connection, or a hydraulic cylinder.

To control the three-point linkage, in particularly modern agricultural tractors, are mainly equipped with control systems to improve work quality and operator comfort during operation. Control Systems have multiple number of algorithms to serve at cross purposes. One of the algorithm for draft control which changes tractor operating conditions depending on the draft force applied by the implement. According to the draft force, control system adjusts engine speed and transmission gears ratio to reduce fuel consumption. The adjustment of the draft control includes two steps; determining the force on the implement then changing engine and transmission work conditions. The operator set a value representing a force which is applied to the implement. Also, the operator can set a working depth value of the implement. The main determinant for the control system is draft force value. All the other system components are adjusted by draft force value. The control system always calculates the optimum fuel consumption according to working depth of the implement and draft force. In this case the control system doesn't reach the optimum fuel consumption. Because the control system only changes engine speed and transmission gears ratio, it doesn't change the implement inputs.

A control system which increases rotation speed of the engine and operates the continuously variable transmission mechanism is disclosed at patent number JP2010022230 (A). Also patent number JP2013188184 (A) is discloses a control system which can set revolutions of an engine and transmission gear ratios to reduce fuel consumption. US2012296532A1 patent application discloses an engine control device for a tractor, which operates such that, in the tractor, the output of the engine is controlled in a fuel efficient engine performance curve for reduced fuel consumption and in a standard engine performance curve for normal fuel consumption.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to control system and method for agricultural tractors, in order to eliminate the abovementioned problems and to bring new advantages to the related technical field.

The main object of the present invention is to provide a control system, and more particular a control system for agricultural tractor which reduces fuel consumption by changing the implement operating parameters.

Another object of the present invention is to provide a control system which can change implements working depth according to reduce fuel consumption.

In order to realize all of the abovementioned objects and the objects which are to be obtained from the detailed description below, A tractor comprising; An engine, a continuously variable transmission which is driven by the engine, a cabin is provided over the transmission; and A three point linkage consisting of an actuating cylinder, a rocker arm connected to the actuating cylinder and a lower lifting arm which is driven by the actuating cylinder over the rocker arm; an implement which is connected to the lower lifting arm; and A control system consisting of a display unit where is provided inside the cabin, a draft load sensor which is provided on the lower lifting arm, a position sensor which is provided on the rocker arm's hinge point on transmission chasing and a control unit which is connected to the engine, the transmission and sensors. The tractor characterized by comprising the control system to improve efficiency of the tractor operating conditions comprises; the control unit arranged to receive and store a plurality of real time operating parameters each associated with operating functions of the tractor via sensors and creates own data library; and an estimator which is engaged to the control unit when the control unit creates the library and which predicts t+1 moment working conditions of the tractor and sends predictions to the control unit in accordance with the data which is archived at the library.

In a preferred embodiment of the subject matter invention, a pressure sensor which is connected to the control unit, is provided on the actuating cylinder.

In another preferred embodiment of the subject matter invention, a radar which is connected to the control unit (31 ), is provided bottom surface of the transmission housing.

In another preferred embodiment of the subject matter invention, to provide measure accurately the rocker arm's rotation movement; a cam is provided on junction point of the rocker arm, adjacent to the position sensor.

In another preferred embodiment of the subject matter invention, to transfer the movement of the rocker arm to the lower lifting arm; a lift rod is provided which is hinged to the rocker arm and the lower lifting arm.

A method for controlling a tractor according to any preceding claim, comprising the step of; a. Defining a working parameters of the tractor to the control system via the display unit by the operator,

b. The control unit starts collecting and storing data from sensors, the radar, the engine and the transmission,

c. The control unit creates a library from stored data when the data reaches predetermined amount,

d. The estimator will be engaged to the control unit,

e. The estimator starts predicting t+1 moment working parameters of the tractor in accordance with the archived data in library,

f. The estimator sends prediction to the control unit,

g. The control unit tries to verify the prediction with the data which shows a possibility of the prediction,

h. The control unit verifies the prediction, makes recalculations and send commands to each associated with operating functions, to reach the most efficient point of the tractor. In another preferred embodiment of the subject matter method, according to the working parameters which are mentioned in item (a) are as follows; the tractor speed, slippage limits, the implement working depth range and draft force comes on the lower lifting arm. In another preferred embodiment of the subject matter method, according to the data which are mentioned in item (b) and which are collected by the control unit are as follows; torque value is created by the transmission, true ground speed, draft force, working depth of the implement, RPM of the engine. In another preferred embodiment of the subject matter method, according to the t+1 moment which is mentioned in item (e) is the next few seconds about the operating moment.

In another preferred embodiment of the subject matter method, according to operating functions which are mentioned in the item (h) are; the engine, the transmission and the three point linkage mechanism.

In another preferred embodiment of the subject matter method, according to the command which is mentioned in the item (h) could be to change RPM to the engine. In another preferred embodiment of the subject matter method, according to the command which is mentioned in the item (h) could be to change gears ratios to the transmission.

In another preferred embodiment of the subject matter method, according to the command which is mentioned in the item (h) could be to change working depth to the implement.

In another preferred embodiment of the subject matter method, according to the library which is mentioned in the item (c) is updated by the control unit when new data is collected.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a side view of tractor

Figure 2 is a sample drawing of an implement attached tractor Figure 3 is a schematic view of sensor circuit

Figure 4 is a flowchart of operating control system REFERENCE NUMBERS

10 Tractor

1 1 Cabin

1 1 1 Seat

1 12 Dashboard

1 13 Steering Wheel

12 Engine

13 Transmission

14 Front Wheel

15 Rear Wheel

151 Rear Axle Housing

16 Hood

20 Three Point Linkage

21 Actuating Cylinder

22 Rocker Arm

221 Cam

23 Lift Rod

24 Lower Lifting Arm

241 Pivot Point

25 Top Link

26 EDC Valve

30 Control System

31 Control Unit

31 1 Estimator

32 Display Unit

33 Pressure Sensor

34 Position Sensor

35 Draft Load Sensor 36 Radar

40 Implement

X Axis

Y Axis THE DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the subject matter control system (30) and control method is explained with references to examples without forming any restrictive effect in order to make the subject more understandable. Accordingly, in the detailed description and in the figures below, the control system (30) is described which has a control unit (31 ) and various types of sensors which are integrated to tractor (10) and connected to the control unit (31 ), to control operating conditions of the tractor (10) according to parameters defined by an operator. Figure 1 shows side view of the tractor (10). The tractor (10) has a transmission (13) and a cabin (1 1 ) which is provided over the transmission (13). The cabin (1 1 ) protects operator from field's external influences. A seat (1 1 1 ) is provided inside the cabin (1 1 ). A dashboard (1 12) is situated, in front of the seat (1 1 1 ), on the inside of the cabin (1 1 ) wall. A steering wheel (1 13) protrudes from top of the dashboard (1 12) towards to the seat (1 1 1 ). When the operator sit the seat (1 1 1 ), can easily reach the steering wheel (1 13). Also a display unit (32) is provided at the top of the dashboard (1 12). The display unit (32) provides the operator with an opportunity to enter various type of information to the control system (30). The display unit (32) can be touch panel or conventional button system panel. It changes operator/customer demand. The tractor (10) has front and rear wheels (14, 15). Rear wheels (15) have a greater diameter than front wheels (14). The tractor (10) has a hood (16) which is provided abut to the cabin (1 1 ), between front wheels (14).

Figure 2 shows schematic view of the control system (30) which is adapted to the tractor (10). The tractor (10) has an engine (12) which is positioned under the hood (16). The Hood (16) protects the engine (12) from field's external influences. The engine (12) is connected to the transmission (13). The transmission (13) is a type of a Hydro-mechanic Continuously Variable Transmission (CVT). For this reason the transmission (13) has a variable displacement piston pump (not shown in figures). The engine (12) creates rotation movement and drives the transmission (13). The transmission (13) has a set of gears which are located inside the transmission chasing. All the gears have different diameters and different positions. Also all the gears are connected to each other. By this way the engine's (12) revolution can be transferred to one gear to another. The revolution of the engine (12) can be change according to the operator usage. The tractor (10) has a three point linkage (20) mechanism which is located rear side of the tractor (10), between two rear wheels (15). The three point linkage (20) has a rocker arm (22), a lift rod (23) and lower lifting arm (24). The three point linkage (20) mechanism is connected to the control system (30). The control system (30) has an Electronic Draft Control (EDC) algorithm to control the three point linkage (20). The rocker arm (22) is hinged to rear axle housing (151 ) top exterior surface from one end. Other end of the rocker arm (22) mechanically jointed to the tip of the lift rod (23). The lift rod's (23) other end is mechanically jointed to the lower lifting arm (24). Also the lower lifting arm's (24) one end is hinged to the rear axle housing (151 ) from bottom exterior surface. The lower lifting arm's (24) tip is connected to an implement (40). Also three point linkage (20) has a top link (25) which can be connected to the implement (40). The implement (40) is attached to the tractor (10) via three point linkage (20) mechanism. A cam (221 ) is structured on the rocker arm's (22) hinge region. The cam (221 ) rotates simultaneously with the rocker arm (22). An actuating cylinder (21 ) is connected to the rocker arm (22). The actuating cylinder (21 ) is driven hydraulically. An EDC valve (26) controls hydraulic circuit which is connected to the actuating cylinder (21 ) and activates the actuating cylinder (21 ). The actuating cylinder (21 ) rod is connected to the rocker arm (22) a region near the tip. Connection region effects momentum force. By this way, lifting capacity of the actuating cylinder (21 ) is increased.

The control system (30) has a central control unit (31 ). The control unit (31 ) has an estimator (31 1 ) algorithm module. The display unit (32) is connected to said control unit (31 ). Operator enters the tractor (10) operating parameters via graphical user interface (GUI) which is provided on the display unit (32), to the control unit (31 ). The control unit (31 ) is connected to the engine (12), transmission (13) and the three point linkage (20). The control unit (31 ) receives data from the engine (12) rpm, the transmission (13) pressure and the three point linkage (20) height related operating conditions. Also, the control unit (31 ) can send commands to aforementioned units. A pressure sensor (33) is connected to the control unit (31 ). On the other hand the pressure sensor (33) is connected to the actuating cylinder (21 ). The pressure sensor (33) sends actuating cylinder's (21 ) working conditions, about pressure inside cylinder, data to the control unit (31 ). A position sensor (34) which is located adjacent to the cam (221 ), is connected to the control unit (31 ). The position sensor (34) measures amount of rotation of the cam (221 ). By this way, the control unit (31 ) is aware of the rocker arm (22) position. A draft load sensor (35) which is provided on the lower lifting arm (24) preferably located over the pivot point (241 ), is connected to the control unit (31 ). A draft load sensor (35) measures the force comes on to the lower lifting arm (24). A radar (36) which is provided bottom surface of the transmission (13) housing, is connected to the control unit (31 ). The radar (36) measures the tractor (10) true ground speed.

Figure 3 shows schematic view of the control unit (31 ) and connected sensor circuit. The control unit (31 ) collects data from the three point linkage (20) mechanism via sensors (33, 34, 35). The control unit (31 ) activate the three point linkage (20) mechanism by actuating cylinder (21 ). The actuating cylinder (21 ) can push or pull the rocker arm (22). When the actuating cylinder (21 ) drives the rocker arm (22) the movement transferred to the lower lifting arm (24) by the lift rod (23). The implement (40) is attached to the lower lifting arm (24). Therefore, when the actuating cylinder (21 ) drives the three point linkage (20) also the implement (40) moves and the implement's (40) depth changes. The control unit (31 ) knows the rocker arm (22) position according to the cam's (221 ) starting point. By this way, the control (31 ) unit can calculate the implements (40) working depth according to the cam's (221 ) rotation amount and position. When it is mandatory with this method the control unit (31 ) can easily to change the implement's (40) working depth.

The draft load sensor (35) measures the force comes on to the lower lifting arm (24) and sends data to control unit (31 ). According to the data the control unit (31 ) calculates the most fuel efficient point according to the defined operating parameters. According to the calculations, the control unit (31 ) can change/changes the gears ratio of the transmission (13), the engine (12) rpm and the implement (40) depth. Also the pressure sensor (33) helps the draft load sensor (35). Pressure of inside the actuating cylinder (21 ) mutually controls the draft force. By this way, the three point linkage (20) precision and accuracy is increased. The control unit (31 ) measures the tractor (10) speed from the ground by the radar (36). Front and rear wheels (14, 15) diameters are different from each other. For this reason measuring the tractor's (10) speed from wheels (14, 15) can cause a problem. The radar (36) measures the speed from the ground gives the true ground speed of the tractor (10). Different between ground speed and wheels speed gives the tractor (10) slippage.

The operator can set the operating conditions of the tractor (10) via the control system (30). The operator defines the operating parameters and enters the data input with the aid of the display unit (32). The operator can select one of the five working mode. Also the operator can set; vehicle speed, slippage limits, the implement (40) working depth range and draft force comes on the lower lifting arm (24). All these data are collected and stored in the control unit (31 ). The control unit (31 ) uses these data as reference operating conditions and makes calculations. The control system (30) tries to keep operating parameters constant whilst the tractor (10) is working. The control system (10) tries to operate the tractor (10) constant speed and the most fuel efficient point. According to the reference data which is defined as operating parameters of the tractor (10), the control unit (31 ) sends revolution per minute (RPM) demand to the engine (12). The engine (12) creates revolutions, torque and drives the transmission (13). Simultaneously the control unit (31 ) sends transmission gears ratio and plate angle of the variable displacement piston pump information to the transmission (13). According to the engine (12) RPM input and gear ratio data the transmission (13) sends torque value to the control unit (31 ) as a feedback. Also the control unit (31 ) collects data from the draft load sensor (35). When the implement (40) is exposed a force over the defined draft force value, the control unite (31 ) changes the engine (12), the transmission (13) and the implement (40) depth working conditions and tries to reach desired draft force value. The control unit (31 ) verifying the draft force value with data which comes from the pressure sensor (33). The control system's (30) difference is came from changing the implements (40) working depth at Y axis while the tractor (10) is working on the field. Field operation starting point the tractor (10) works according to the operating parameters which are defined by the operator. While the tractor (10) is working on the field the control unit (31 ) starts collecting data from field, stores them and creates own library. When the control unit (31 ) creates library, it continues to collect data overwrites them to the library. By this way the control unit (31 ) always keep the library is updated. When the control unit (31 ) receives sufficient amount of data, starts working as adaptive driving mode. When the control unit (31 ) creates the library and activates the adaptive driving mode the estimator (31 1 ) module is engaged. According to collected data the estimator (31 1 ) predicts the t+1 moment's draft force which is the next few seconds about the operating moment. The estimator (31 1 ) sends predictions to the control unit (31 ). If the control unit (31 ) receives any parameter to confirm prediction, it will send commands to the engine (12), the transmission (13) or the three point linkage (20) to change operating parameters. The control unit (31 ) response time is reduced by the estimator (31 1 ). Figure 4 shows the flowchart of the control system (30). Under the light of the abovementioned information, the control system (30) works as follow; the operator gets inside the cabin (1 1 ) and enters the tractor (10) operating parameters via the display unit (32) to the control system (30). The control unit (31 ) makes first calculations and send commands to the engine (12) and the transmission (13). The three point linkage (20) lowers the implement (40) predefined working depth. The tractor (10) moves on the field with constant speed. During the draft applications in the field the draft force comes on to the implement (40) at X axis. Simultaneously the control unit (31 ) is collecting data from sensors (33, 34, 35) and creates library. When the library is created the tractor (10) changes working mode as adaptive driving and the estimator (31 1 ) unit is engaged to the control unit (31 ). According to the library the estimator (31 1 ) makes predictions about to t+1 moment and sends them to the control unit (31 ). When the control unit (31 ) receives any data to verify prediction, it sends new commands to related unit. By this way the control unit (31 ) tries to reach the most efficient working point of the tractor (10) and reduces fuel consumption.

Above mentioned command can be related to the engine (12) revolution amount, or the transmission (13) gears rotation ratios or the implements (40) working depth. The control system (30) apart from the conventional methods and changes the working depth of the implement (40) inside the permissible limits. Thus the control system (30) adds the implement (40) and the three point linkage (20) working conditions to the efficiency calculations.

The adaptive driving mode can be disabled by the operator. It isn't mandatory for the tractor (10) usage. The tractor (10) can be used only the operating parameters which are defined by the operator.

Claims

A tractor (10) comprising;

An engine (12), a continuously variable transmission (13) which is driven by the engine (12), a cabin (1 1 ) is provided over the transmission (13); and

A three point linkage (20) consisting of an actuating cylinder (21 ), a rocker arm (22) connected to the actuating cylinder (21 ) and a lower lifting arm (24) which is driven by the actuating cylinder (21 ) over the rocker arm (22); an implement (40) which is connected to the lower lifting arm (24); and

A control system (30) consisting of a display unit (32) where is provided inside the cabin (1 1 ), a draft load sensor (35) which is provided on the lower lifting arm (24), a position sensor (34) which is provided on the rocker arm's (22) hinge point on transmission chasing and a control unit (31 ) which is connected to the engine (12), the transmission (13) and sensors (34, 35);

Characterized by,

the control system (30) to improve efficiency of the tractor (10) operating conditions comprises; the control unit (31 ) arranged to receive and store a plurality of real time operating parameters each associated with operating functions of the tractor (10) via sensors (34, 35) and creates own data library; and

An estimator (31 1 ) module which is engaged to the control unit (31 ) when the control unit (31 ) creates the library and which predicts t+1 moment operating conditions of the tractor (10) and sends predictions to the control unit (31 ) in accordance with the data which is archived at the library.

A tractor (10) according to claim 1 , a pressure sensor (33) which is connected to the control unit (31 ), is provided on the actuating cylinder (21 ).

A tractor (10) according to claim 1 , a radar (36) which is connected to the control unit (31 ), is provided bottom surface of the transmission (13) housing.

A tractor (10) according to claim 1 , to provide measure accurately the rocker arm's (22) rotation movement; a cam (221 ) is provided on junction point of the rocker arm (22), adjacent to the position sensor (34).

A tractor (10) according to claim 1 or claim 4, to transfer the movement of the rocker arm (22) to the lower lifting arm (24); a lift rod (23) is provided which is hinged to the rocker arm (22) and the lower lifting arm (24).

6. A method for controlling a tractor (10) according to any preceding claim, comprising the step of;

a. Defining a operating parameters of the tractor (10) to the control system (30) via the display unit (32) by the operator,

b. The control unit (31 ) starts collecting and storing data from sensors (33, 34, 35), the radar (36), the engine (12) and the transmission (33), c. The control unit (31 ) creates a library from stored data when the data reaches predetermined amount,

d. The estimator (31 1 ) will be engaged to the control unit (31 ),

e. The estimator (31 1 ) starts predicting t+1 moment operating parameters of the tractor (10) in accordance with the archived data in library, f. The estimator (31 1 ) sends prediction to the control unit (31 ),

g. The control unit (31 ) tries to verify the prediction with the data which shows a possibility of the prediction,

h. The control unit (31 ) verifies the prediction, makes recalculations and send commands to each associated with operating functions, to reach the most efficient point of the tractor (10).

7. A method according to claim 6, according to the operating parameters which are mentioned in item (a) are as follows; the tractor speed, slippage limits, the implement (40) working depth range and draft force comes on the lower lifting arm (24).

8. A method according to claim 6, according to the data which are mentioned in item (b) and which are collected by the control unit (31 ) are as follows; torque value is created by the transmission (13), true ground speed, draft force, working depth of the implement, RPM of the engine (12).

9. A method according to claim 6, according to the t+1 moment which is mentioned in item (e) is an operating conditions of the next few seconds about the operating moment.

10. A method according to claim 6, according to operating functions which are mentioned in the item (h) are; the engine (12), the transmission (13) and the three point linkage (20) mechanism.

11. A method according to claim 6, according to the command which is mentioned in the item (h) could be to change RPM to the engine (12).

12. A method according to claim 6, according to the command which is mentioned in the item (h) could be to change gears ratios to the transmission (13).

13. A method according to claim 6, according to the command which is mentioned in the item (h) could be to change working depth to the implement (40).

14. A method according to claim 6, according to the library which is mentioned in the item (c) is updated by the control unit (31 ) when new data is collected.