FR2723792A1 - Computer system to assist operation of agricultural tractor - Google Patents

Abstract

The system has a variety of sensors and actuators coupled to the central computer. A gear selector (12) allows change of ratio under load. The engine control electronics (13) responds to an exhaust temperature detector (19), a detector (14) for accelerator (15) position. Another electronic unit (6) controls the tool attached to the tractor, using signals from detectors (5,7) at the attachment of the tool, and a tractor speed detector (9) and a driven wheel (8) speed detector (10). The central computer (17) has a static database and a supervisory program. The central computer is connected directly to the transmission control (12), to the tool actuators (6) and to a man- machine interface. The supervisory program ensures optimum operation under the work parameters set by the operator.

Description

 The present invention relates to driving agricultural tractors and the tools they carry or that they drive.

 The agricultural machinery has known many technological innovations due mainly to the introduction of electronics.

 These innovations consist in improving existing functions, for example the electronic linkage control or gearboxes with torque shifting, or in implementing new functions, for example assistance with economical driving or skid control. These innovations, which aim to improve the productivity of the tractor-tool system and driving comfort for the driver, however, admit of limits revealed by user experiences.

 First of all, with regard to the ergonomics of communication, the control logic of electronic systems is not always designed to be compatible with the needs and skills of the farmer. For example, to obtain a given working depth, which is an important parameter for a farmer, the latter must himself set the values of several setpoints (position, effort, sensitivity) whose meaning he does not fully understand.

 Similarly, the same forward speed can be obtained with several torques (engine speed, transmission ratio), only one minimizing fuel consumption and it is not necessarily the torque which is chosen by the driver.

 In addition, most of the electronic control devices operate independently, so that the coordination of the assembly is entrusted to the driver who assures him more or less well and the efficiency of driving the tractor-implement system. depends on the driver's experience and skill.

 Finally, the effectiveness of this coordination of the entire tractor and the on-board systems requires monitoring the evolution of the operating parameters of the various elements.

 However, each element has its own display device and these devices are distributed throughout the cabin, which creates discomfort and fatigue for the driver.

 A device for minimizing fuel consumption is known, for example, which indicates to the driver the optimum engine speed / transmission ratio pair. This device, which can automatically ensure the shifting of gears, does not help the initial configuration and does not take into account the tools carried or dragged by the tractor.

 There are also automatic control devices for spraying booms or precision seed drills which also operate independently of the other elements of the tractor-tool system.

 Finally, a unique display device for a combine harvester is known which continuously supplies information relating to the harvesting, maintenance, adjustments or maintenance of the machine. It is only an information device and decisions regarding driving and operation are taken by the driver.

 The present invention proposes to provide a device for assisting the driving of an agricultural tractor and its tools which makes it possible to configure all of the elements, tractor and tools, as a function of working parameters characteristic of the cultivation operation. forecast (depth, speed, spraying rate, etc.) and to determine an automatic operating program which takes into account variations in the various operating parameters.

 To this end, the subject of the invention is a driving assistance device for an agricultural tractor, comprising a transmission device with a speed selector with torque shift, an electronic engine control device acting on the injection system. and associated with an exhaust gas temperature sensor, at least one accelerator control position sensor, at least one electronic device for controlling a implement carried or dragged by the tractor, this control device of tool being associated with at least one sensor, and sensors, such as a sensor for the speed of movement of the tractor and a sensor for the speed of rotation of the driving wheels, characterized in that it comprises a central computer comprising a static database and a supervisor program, the central computer being connected directly to the transmission device, to the engine control device, to the tool control devices, & a human-machine dialogue interface and to the various sensors, the supervisor program determining, as a function of work parameters set by the driver, an automatic operating program controlling the engine control device, the transmission device and the implement control, the central computer automatically controlling the entire tractor and its implements according to a work criterion, such as an economic, agronomic or temporal criterion, so as to optimize the management of this together.

 In this way, automatic operation of the tractor and its implements is obtained, the conditions of which are optimized. The automatic operating program is determined taking into account all the working parameters based on operating data, such as maps, stored in the static database.

 According to another characteristic of the invention, the central computer comprises a dynamic database receiving the data supplied by the various sensors and the automatic operating program takes into account the variations in the operating parameters.

 Thanks to this arrangement, the operation in automatic mode is optimized with respect to variations in the working parameters. In particular, the engine control takes into account the operating conditions of the tools.

 According to yet another characteristic of the invention, the driving assistance device comprises a manual control device activating a manual control mode in which the central computer is passive, provides information and determines the operating program automatic.

 This arrangement allows the driver to manually drive the tractor to the work area and to set the work parameters interactively. The supervisor program then determines the automatic operating program on the basis of these working parameters and operating laws provided by the static database.

 This also allows you to instantly switch to manual mode in an emergency.

According to yet another characteristic of the invention, the driving assistance device comprises a standby device activating a standby mode in which the automatic operating program is interrupted and stored.
This arrangement makes it possible in particular to drive the tractor without the tools operating to make a U-turn at the end of the row or to deal with any unforeseen event.

 Advantageously, this standby is controlled by a push button.

 According to yet another characteristic of the invention, the automatic operating program comprises a procedure for limiting the slip of the wheels.

 Advantageously, the interface includes a sound information device. This makes it possible to provide information to the driver without having to look at the visual display device, in particular during the automatic mode.

 Furthermore, the interface advantageously includes a keyboard with reconfigurable keys. This makes it possible to use a space-saving interface comprising a small number of keys.

 According to yet another characteristic of the invention, the interface provides a message when an event, such as a variation of an operating parameter, occurs and, in the case of several simultaneous events, the message indicates the event which is taken into account first by the automatic operating program.

 This allows the driver to understand the automatic changes that are applied to the operation, such as a change in engine speed.

 Other characteristics and advantages of the invention will emerge from the description which follows of an embodiment of the invention, made with reference to the appended drawings in which: - Figure 1 is a schematic representation of a tractor comprising a lifting control device and equipped with a driving assistance device according to the invention; - Figure 2 shows an interface, - Figures 3 and 4 show two pages of information and interface control; - Figure 5 illustrates the different operating modes and the transition from one mode to another - Figure 6 illustrates the operation in automatic mode - Figures 7 and 8 represent examples extracted from the static and dynamic databases, respectively ; - Figure 9 shows the speed up phase of the automatic program; and - Figures 10 to 14 are examples of display of the interface.

 FIG. 1 schematically represents a tractor 1 which carries a carried, sesi-carried or trailed tool, such as a plow (not shown), fixed on a lifting device comprising two arms 2 actuated by jacks 3 controlled for example by at minus an electro-hydraulic proportional valve 4.

 The position of the arms 2 is identified using position sensors 5 connected to an electronic device 6 for controlling the lift. Force sensors 7 arranged for example at the lifting arms 2 measure the traction force exerted by the tractor and are connected to the lifting control device 6.

The slippage of the drive wheels 8 of the tractor is evaluated using a sensor 9 for the speed of movement of the tractor, for example by radar, and a sensor 10 for the speed of rotation of the drive wheels 8
The tractor 1 is equipped with a transmission device 12 for torque shifting constituted by an inverter and an electro-hydraulic tripler and which makes it possible to triple a basic speed without disengaging or stopping the tractor.

 The tractor 1 also includes an electronic device 13 for controlling the injection pump as a function of operating parameters supplied by a sensor 14 the position of the accelerator pedal 15 and by a sensor 19 of the temperature of the exhaust gases. as well as the engine speed which is supplied by the transmission device 12. This control is carried out using a servomotor 16 which acts on the injection pump.

 In accordance with the invention, the driving assistance device essentially comprises a central computer 17 to which the computing unit 11 are connected, the lifting control device 6, the injection control device 13, the sensors 9, 10, 14 and 19 of operating parameters and the transmission device 12.

 The driving assistance device according to the invention also includes a man-machine interface 18 and a sound information device 205 constituted for example by loudspeakers for the reproduction of sound messages which are connected to the central computer 17. Two boxes 21 and 22 disposed respectively at the front and at the rear of the tractor 1 make it possible to connect the central computer to tools such as a seed drill or a sprayer and to control these tools. Digital connections, not shown, make it possible to control the electro-distributors and the power take-offs located at the front and rear of the tractor 1.

 FIG. 2 is a detailed view of the interface 18. The interface comprises, at its lower part, a digital keyboard, a help key 31, a key 32 for controlling the sound of the keys, a key 33 d stopping the message in progress, a key 34 for activating manual mode, a key 35 for activating automatic mode, a key 36 for adjusting the screen contrast, a key 37 for repeating the last audible message and a key 38 for accessing the automatic mode menu. This man-machine interface also includes reconfigurable keys 39.

 The display screen comprises three zones, a header zone 41, a status feedback zone 42 and a menu zone 43 arranged opposite the reconfigurable keys 39. I1 is a screen '' single display on which all the information necessary for determining the automatic operating program and driver information is displayed. For this purpose, the interface 18 is placed in the cabin at a location where the screen is visible to the driver while he is driving. FIGS. 3 and 4 are examples of screen pages displayed by the interface 18.

 FIG. 5 schematically illustrates the three operating modes of the device according to the invention. Blocks 51 to 53 symbolize the manual control mode, the automatic operating mode and the standby mode, respectively. The arrow 54 represents the actuation of the key 35 which causes the passage from manual mode to automatic mode. The arrow 55 represents the actuation of the key 34 which causes the reverse passage. These two orders can be made at any time.

 The arrows 56 and 57 represent the actuation of the control device of the tool used, the lifting control button in the case of plowing. When the tool is stopped (raising the arms, arrow 56), we go from automatic mode h, a standby mode in which the automatic operating program is inhibited and the current configuration is stored, the control being manual . This corresponds, for example to the U-turn at the end of the row. After this U-turn, lower the arms (arrow 57) and return to automatic mode.

 The automatic mode comprises three phases, an initialization phase during which the driver enters work data which a supervisor program housed in the central computer will use to determine an automatic operating program, a speed-up phase. of the tractor and progressive implementation of the automatic program and a real-time management phase based on the information provided by the operating parameter sensors.

 FIG. 6 is a flow diagram of the operation of the device according to the invention. While the tractor is stopped, a first step 61 is the choice of work by the driver. During a second step 62, menus are offered to the driver so that he fixes the working parameters, for example the type of soil, the characteristics of the tools, and a working criterion, such as fuel economy, working time or an agronomic quality of work (for example maintaining a constant plowing depth, even if this leads to less than optimal consumption). The driver can choose a predefined program (settings memorized for a given plot).

 In a third step 63, the supervisor program performs an initial configuration by fixing different thresholds or operating parameters by consulting tables or maps of a static database 69. The program can thus set the engine speed, the transmission ratio, the maximum slip depending on the type of soil, etc.

 The interface 18 then displays these various parameters. The driver can then (step 64) modify the value of certain parameters. The speed-up phase 66 is described in detail in FIG. 9. Then the tractor drives and we pass to phase 67 of real-time management during which the operating parameter sensors send their signals to a base 71 of dynamic data (step 68) and the automatic program reacts on the elements of tractor 1 (arrow 72).

 Figures 7 and 8 give examples of information from the static database 69 and the dynamic database 71 for plowing work.

 FIG. 9 describes in detail the speed-up phase in the case of plowing, this phase ends with phase 67 of real-time management.

 Figures 10 to 14 show interface messages for plowing work. Figure 10 corresponds to step 61 in Figure 6, Figure 11 in step 62, Figure 12 in step 63, Figure 13 in step 66 and Figure 14 in step 67.

 We see that the supervisor program provides a single interface between the driver and the various on-board electronic control devices. The messages sent to the driver are in clear, that is to say in the language of agriculture. All these control devices are coordinated in order to obtain optimal operation from all points of view, in particular with regard to fuel consumption. Finally all the information is centralized on a single screen.

 The above description has been provided for illustration only and is in no way limitative and it is obvious that modifications or variants can be made without departing from the scope of the present invention. In particular, the invention can be applied to the control of tools other than a plow. The invention makes it possible to optimally control combined tools such as a soil preparation apparatus and a seed drill which may also be arranged respectively at the front and at the rear of the tractor.

Claims (9)

 1. Driving assistance device for an agricultural tractor, comprising a device (12) for transmission & speed selector with torque shift, an electronic device (13) for controlling the engine acting on the injection system and associated with an exhaust gas temperature sensor (19), at least one accelerator control position sensor (14), at least one electronic device (6) for controlling a carried tool, or trailed by the tractor, this tool control device (6) being associated with at least one sensor (5,7), and sensors, such as a sensor (9) for the speed of movement of the tractor (1) and a sensor (10) for the speed of rotation of the driving wheels (8), characterized in that it comprises a central computer (17) comprising a static database (69) and a supervisor program, the central computer ( 17) being directly connected to the transmission device (12), to the device (13) for controlling the motor, to tool control devices (6), to a hone-machine dialogue interface (18) and to the various sensors (5, 7, 9, 10, 14 and 19), the supervisor program determining, according to working parameters set by the driver, an automatic operating program controlling the engine control device (13), the transmission device (12) and the tool control devices (6), the central computer controlling automatic the whole tractor and its tools according to a work criterion, such as an economic, agronomic or temporal criterion, so as to optimize the management of this set.  2. Driving assistance device according to claim 1, characterized in that the central computer (17) comprises a base (71) of dynamic data receiving the data supplied by the various sensors (5, 7, 9, 10 , 14 and 19) and by the various control and piloting devices (6, 12 and 13), and in that the automatic operating program takes account of variations in the operating psarameters.  3. Driving assistance device according to claim 1, characterized in that it comprises a device (34) for manual control activating a manual control mode in which the central computer (17) is passive, provides informations.  4. Driving assistance device according to claim 1, characterized in that it comprises a standby device activating a standby mode in which the automatic operating program is interrupted and stored.  5. Driving assistance device according to claim 4, characterized in that the standby is controlled by a push button.  6. Driving assistance device according to claim 2, characterized in that the automatic operating program comprises a slippage limitation procedure.  7. Driving assistance device according to claim 1, characterized in that the interface (18) comprises a sound device (20) for information.  8. Driving assistance device according to claim 1, characterized in that the interface (18) comprises a keyboard with reconfigurable keys (39).  9. Driving assistance device according to claim 1, characterized in that the interface (18) provides a message when an event such as a variation of an operating parameter occurs and in that, in in the case of several simultaneous events, the message indicating the event which is taken into account by the automatic operating program.