CA1323987C - Method and system for automatically steering along row crops - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

The present invention relates to automatic methods and systems for steering along row crops and preventing accidents during automatic steering, and more particularly to automatic methods fox steering among row crops adapted for use in settings where thicknesses of plants vary.

Description

~323~7 MET:~IOD AND SYSTEM FOR
~U~I:~ATICALLY Sl~:RING ~I~ONG P~Oh' CROPS

' BACXGRQUND

~he present invention relates to automatic methods 20 and systems for ste~ring along row crops and pseventing accidents during automatic . teering, and more particularly to autom~tic methods for steering among row crops adapted for use in settings where thicknesses of plants vary .
25 Back 3round A~
Automatic steering methods among row ~rops are commonly used in harves~ing where thicknesses of plants ehange within a row, and they may be used elsewhere as well. In various applications, a hum,an operator may lack 30 the skills needed to steer eficierltly ~n agricultural machine~ e.g., a harvester. In these and other , ~3~3~
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applications, a self-sufficient aut~matic stee~in~ method is indicated. However, if the h~man operator relies on automatic steering, through inat~entiveness or preoccupation with other tasks the operator may miss gaps 5 which occur in rows and allow the machine to overr~n a ~ row end, risking serious accident. ~ence, a :~ self-s~lfficient steering method must also be safe.
Conventional methods sense a deviation from 2 desired, straight ahead cou~se and then correct t~.e deviation 50 as to steer on a straight courseO Sevcral patents show this approach, U.S. 4,367,802 (Stiff et al.), ~.S~ 4,366,756 (Brum~, U.S. 3,797,602 (Sumida), U.5. 3,550;790 (N~ble), and U.S. 3,402,784 (Roberson), . each ~sing a furrow plouyhed in the ground for guidance.
U.S. 4~345,659 (Arnold) shows a v~riation for sod harvesting. Sometimes it is impractical to follo~ a , furrow in the ground. Accordingly, methods emplo~- dual resilient sensin~ arms which press against ~he risht and left side ~f a row of crops and then generate on-off correction signals, as ~.S~ 4,528~804 (~illiams) and a companion patent, U.S. 4,505,094 ~Demorest~ disclose.
, The object of al.l of these metbods essentially is to steer straight ahead. To do this, the methods re~uire some sort of feedback which measures a corrective motion so that the tending machine attains a straight ahead course. ~or instance, this feedback appears in me~hods employing resilient crop-sensing arms. It takes 2 form there of a simple expedient o~ halting turning once the arm loses contact with the c~ops.
~' 30 As the thickness of the plants changes, sensing members wh~ch press against the left and right siaes of ~3~ 1~3~

the plants may generate contradictory signals.
Consequently, a hiat~s in sensing may occ~r t and so~etimes a human oper~tor must monitor steering and freguently override an a~tomatic system. Hence, variation in plant thicknesses presents a special kind of problem.
~ .S. 4,304,316 (Lang) addresses this problem. It shows left and right resilient arms that generate hydraulic signals Xl and X2. These signals indicate a degree of steering error, thus they are quantitative. An ar~, 40 (or.in a separate embodiment~ a lever 86) within a : hydraulic chamber produces an output hydraulic signal which i~ the absolute value of a difference Xl _ X2 between the signals. This process compensates for variations in plant thickness. However; this approach entails some new difficulties. This method includes a step, namely, correlating a corrective motion to a ~uantity of steering error. Without this step, the machine would not steer on a straight ahead course~ To execute this step, this method requires hydraulic equipment, ho es and a valve body. Also, the f`act ~hat this method is self-suffieient and that a human operator is disengaged from driving the machine, heightens a need for protection against possible overrunning of row ends.
A type of gap protection is known in grass and grain crop steering ~ethods. ~.S~ 3,~52,828 (Stampfer et al.) shows left and right detectors 86 and 86', which sense the presence or absence of grain. At the end of a field they both generate signals which tell the harvester to h21t. Ho~ever, this process reguires a field crop. Row :

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crop steering methods still lack a sati~factory W2y to pro~ect against overrunning of gaps and row ends.
Signals which an automatic steering system ger.erates when contacting plants in a row, indicate the presence of ~ 5 the row. A gap in these signals can warn of a gap in the : ro~. However, because of the focus of conventional me~hod5 on steering straight ahead, wherein an objective is to minimize row contact, ~he use of contact signals for gap detection is often forgotten. Additionally, hydraulios, or other means of guantitatively correlating corrections with errors~ in certain circumstances can co_plicate the automatic steering process. The state of ~ the art still insists on steering straight ahead only.
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S 11MMA RY OF THE I NVENT I O~' . Accordingly, it is an object of the present invention to steer a row crop tending machine 5 self-sufficiently among crops of varying thicknesses.
: Another object of the invention is to exploit ~ contact signals which a steering system generates thus .: preventing accidents due to ~he overrunning of gaps in rows and row ends.
Another object of the invention is to provide simpler methods and systems ~or monitor ing a course and : crop thicknesses, thereby reducing steps, the number of ~` components, and cost.
Another object of the invention is to steer sufficiently close to row crops ~or a variety ~f agricultural applications.
The present invention accomplishes these and other . objects which are apparent from consideration of the detailed description and claims.
In an e~bodiment of the invention, a machine used in agricultural operation, such as harvesting, has an ~utomatic ~teering means and an automatic machine shutdown means. As used herein, a direction ~forward~
!i I means the usual direction of travel of the chassis a direction ~outward~ means away from the row of crops.
The automatic steering means of ~he invention includes the ~ollowing functional elements: a turning ; means, such as a steerable, ground-engaging wheel; a monitor ing assembly; a pivoting control means; and a pivotposition monitoring means. The row location assembly determines the location of first and second , i .~. . :
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-6- ~3~3~87 sides of the row with respect to the machineO ~he monitoring assembly, which co~municates with the row locating assembly, monitors those locations and determines the location of a row axis or centerline with respect to the machine regardless of variations in the thicknesses of plants within the row. The turning means has first and second pi~ot limits both of which are angularly displaced from an alignment axis (which represents the direction in which the machine steers when moving straight ahead). The pivoting means moves the turning means angularly to either the f irst pivot limit or the second pivot limit. The pivoting control means directs the pivoting means to move toward the first pivot limit, to cease pivoting, or to move to the second pivot limit. Conditions where an alignment location fixed on the machine is off to first and second sides of the row centerline, respectively, are called ~firs~ and second turn conditionsn. Assuming that the first ~urn condition exists, the monitoring assembly imparts a signal to the pivo~ing control means, which starts the turning means (steerable wheel) moving toward its first pivot limit~
When the turning means attains the irst pivot limit, the pivot position monitor which i5 connected to the turning means imparts a signal to the pivoting con~rol means which ceases pivoting of the turning means. The ~urning means is now in the first pivs~ limit snd the machine steers itself back toward the row centerline.
Assuming that the second turn condition exists, the monitoring assembly imparts a signal to the pivoting control means which causes the turning means to ~.ove toward the second pivot limit. When the turning means . . .

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reaches its second pivot limit, the turning means monitoring means imparts a ~ignal to the pivoting control means which ceases pivoting of the turning means. The turning means is now in its second pivo~ limit and the machine steers back toward the row centerline.
Assuming in each case des~ribed ~hat ~he row axis centerli"e is approximately straight, the described process repeats in cycles whereby the machine describes a i path oscillating between the machine's first and second sides. ~
In this embodiment, the row locating assembly includes first and second, longi~udinally extending, generally parallel, locating members. Each locating member has a forward portion, a middle portion, and a 15 rearward portionr the forward portion curving forwardly and outwardly, and 'che middle portion aligning generally parallel to the row. The ~irst locating member presses ,iagainst a first side of the row and the second locating member presses against a second side. Re ilient means ~20 connected to the loca~ing members provides the pressing ., force, Also, the monitoring assembly comprises first and second substantially parallel monitoriny bars. These monitoring bars mutually define a monitoring pathway.
The first monitoring bar is extendable in a first monitoring direction and retractable in a second, opposed moni~oring direction; the second monitoring bar is extendable in the second monitoring direction and retractable in the first monitoring directionO ~ linkage ~eans, comprising arms and rods~ connects the first and , second locating members to the first and second ,~

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r.onitoring bars. The linkage means is arranged in a ~.anner such that a displacement of the first monitoring bar in the first direction corresponds to an outward displacement of the first locating member, and a 5 displacement of the second monitoring bar in the second direc~ion corresponds to an outward displacement of the second locating member. A monitoring wheel which engages both of the monitoring bars is posi~ioned be~ween the .onitoring bars. Preferably, each of the monitoring bars 10 is a toothed rack, and the monitoring wheel is a toothed gear which engages the racks.
A technique as follows monitors the location of the row centerline in relation to the machine. In the monitoEing pathway in a housing, at ~eparate loca~ions, s 15 are placed first and second monitoring switches. The monitoring wheel connects pivotally to a movable housing.
The monitoring wheel and ~he movable housing are moun~ed in a channel means in a fixed housing in which they move back and forth together~ Then, they move back and for~h 20 in response to the extension and retraction of the first and second monitoring bars. Due to ~he monitoring wheel~s engagement with the first and second monitoring I bars~ the monitoring wheel moves in ~he first monitoriny s direction in the monitoring pathway when the first turn ~ 25 condition exists. It moves in the second monitoring direction in the monitoring pathway, when the second turn condition exists. Preferably, the positions of the t~o monitoring switches are arranged so that the followin~
occurs: the swi~ch activating member activates the first 30 and second monitoring switches when the first and second ~rn conditions exist, respectively. It is also possible ., s 's .
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~32~987 to position the s~itches in a m3nner t~ delay their ac~ivati~n beyond the descri~ed activation~ alth~ugh this reduces the invention's sensitivity to the first and r econd turn conditions.
When in the first and s~cond pivot limits, the steerable wheel turns the machine toward the machine 's first and ~econd sides, respectively, (the machinels first side corresponding to the first locating me~ber;
the machine's second side opposing the first side). The 10 pivot limit monitoring means monitors the steerable ~heel 's att.ainment of the fiIst .and second pivot limits and, once a pivot limit is attained, keeps the steerable ~heel in that pivot limit until there is change in the t~rn condition. The pivot limit monitoring means lS includes the following components. The pivoting n~eans connects to an arc-shaped-~itch activa~or which rotates ~hrough an angle that includes the first and second pivot limits. The arc-shaped switch activatc~r describes a path as it pivots. First and second limit switches are 20 positioned adjacent to th~t path in a manner such that the arc-shaped switch activator activates, respectively, the first and second limit ~witches when the steerable ~heel is in the first and ~e~ond pivot limits.
The described automatic steering ~omponents operate 25 2s follows. Assuming that the machine is in the first turn condition, an outward-rearward displacement of the first locating member exceeds such a displacement of the ~econd locating member, the extension of the f irst -.onitoring bar in its first monitoring direction exceeds the extension of the second monitoring bar in its second ~onitoring direction~ and the monitoring wheel is :, , :
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3L3~3~87 displaced in the first monitoring direction. The i n,onitoring wheel and accompanying switch activating member activates ~he ~irst monitoring switch. Then, being activated by the pivoting control means, the pivoting means pivots the steerable wheel toward the first pivot limit. Once the first pivot limit is attained, the first limit switch causes the pivoting control means to halt the pivoting of the steerable wheel which keeps the steerable wheel in the first pivot limit.
The chassis now turns toward its first side. When the chassis is in the second pivot limit, a mirror image of ~ the process just described oceurs, wherein the row l monitoring means and the pivoting control means, cause the steerable wheel to pivot toward the second pivot limit, the pivot limit monitoring means and the pivoting control means keep the steerable wheel in the second ;; pivot limit, and the chassis turns toward its second :i side. Angles between the first and second pivot limits and the alignment axis are preferably about three to five degrees.
Now, the general features of the automatic machine shutdown means are detailed. Eacb displacement of one of i the locating members constitutes a displacement signal, ;/ Thus, in the process of locating the row, the automatic ~5 steering means generates a plurality of such displacement signals. The automatic machine shutdown means stop the :` operation and loco~otion of the maehine when a predetermined amount of time elapses wi~hout any . displacement signal occurring.
-, 30 The automatic machine shutdown means functions as follows. Near the first and second monitoring bars, a .~

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plurality of displacement monitoring shitches are positioned in a way that enables the switches to sense an extension of either of the monitoring bars. Such an extension indicates displacement of the f irst and second 5 row locating members. Time measuring means which co~municates with the displacement moni~oring switches ~easures time elapsing between displacements of the locating members. If a predetermined amoun~ of ti~.e elapses without any such displacement occurring, t~.en 10 ~.achine shutdown ~eans operatively connected to the time me asur ing means shuts down the machine.
O~her features of the present invention will become apparent from the following descr iption.

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13~3~7 BRIEF DESCRIPTION OF THE DRAWIl~GS

PIGURE 1 is a plan view of a harvester embvdying the teachings of the present invention, with portions of the body and a housing, which cove~s a rack and gear assembly, removed for purposes of illustration:
FIG~RE 2 is a front end view of the harvester of Figure 1~ illustrating just a chassis, ground wheels, and certain components of the present invention;
FIG~RE 2A is a front elevational view of a steerable h~heel Df the present inven~ion moun~ed to a harvesting machine's chassis, with position monitoring components;
FIGURE 3 is a view similar to Figure 1 ~howing operation of components of the present invention;
FIGURE 4 is a plan view of a rack and gear assembly of the invention, with a portion of its housing re~oved;
FTGURE 5 is a plan view of a steerable wheel of the present invention shown in a first and a second pivot limit;
FIGURF 6 is a circuit diagram including steering control and safety component~ of the present inYention;
FIG~RE 7 is a plan view of a p2th along which a .achine employing the teachings o~ the present invention travels;
FIGURES 8A through 8F are schematic views of row .onitoring components, row loc3ting bars, and a steersble ~ ~heel of the present invention in v~rious conditions of ,~ opera~ion;
FIGURE 9 is a diagram o~ a hydraulic drive system of a harvester employing features of the present invention;
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~3~8'7 FIGURE 10 is a diagram of logic ~sed in the present invention.

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DESCRIPTION OF THE_PREFERRED EMBODIMENT
A preferred embo~iment of ~he invention is directe~
~oward an automatic steering means 4 and an automatic machine shutdown means 8 by which a machine 10, used in harvesting or in other agricul~ural operations, is located laterally with respect to a rvw 12 of crops ~hich the machine 10 is tending and also is shut down in situations to preven~ accidents in the operation of t~,e ~,achine 10.
Before describing the components of the automatic means 4 and 8 in summary and in detail, it is believed it would first be helpful to desoribe the machine 10 and the machine's environment. As shown in Figures 1, 2, an~ 3, the row 12 of crops comprises a plurality of plants certain portions of which, for instance stem portions 13 thereof, provide the machine 10 with a means of guidance for steering along the row 12. These portions 13 are used by the automatic steering means 4 as an index for locating the position of the row 12 with respect to the machine 10 and by the automatic ~achine shutdown means 8 or generating displacements of row loca~ing members, to be described below, to indicate whether the row is pre~ent or absent. Accordingly, the portions 13 provide first and second lateral locating indices 15 and 16, which are surfaces tha~ the locating members to be described engage laterally, and a row axis 17 which is located centrally between the lateral indices 15 and 16.
Additionally, the plants in the row 12 have upper foliage portions f.
To continue describing the machine's 10 environ~,ent, agricultural operations, as indicated in Figure 1~ are .
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performed by the machine 10 as follows. As the machine 10 moves along the row 12, the row 12 enters and passes rearwardly thro~gh an enclos~re 18 in the machine 10, where two banks of 3gricultural operating eg~ipment 19, 5 positioned on either side of the enclosure 18~ perform agr icultural operations such as harvesting on the row 12.
The equipment 19 includes crop beating means for dislodging produce from the crops.
Also, in terms of structure, as Figures 1 and 2 show best, the machine 10 itself comprises a chassis 20 and a body 21. To support and steer the chassis 20, the chassis 20 is mounted on two n~n-steerable ground wheels 24 and a turning means~ such as a steerable wheel 28, mounted on a pivot mounting means 36 f~r pivoting about a vertical axis 38 of ~he wheel 2B as shown in Figure 2. The chassis 20 then is the illternal frame which connects the s~ceerable wheel 28 in front and the two rearward drive wheels 24. As Figure 1 show~, the bc>dy 21 comprises an attendant 's portion 40 and an operating por~cion 44 connected together by a structl~ral member 45~ which is considered part of the chassis 20.
q The structural member 45 is able to move vertically up and down ~dith respect to the rear wheels 24, thereby r2ising and lowering the operating portion 44 to which the structural member 45 is connected. The portion 40 !~ provides the attendant with a supporting platform which allows riding upon the machine 10 and a steering - wheel 48, rotation of which pivots the steerable wheel 28 for on-the road steering and other maneuvering, ~uch as maneuvering in headlands. The ~perating portion 4g has a forward end member 52 which connects two sidewalls 56.

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The paragraphs that follow first summarily describe the functioning of the automatic steering means 41 this description being followed by a more detailed description. ~dditionally, the automatic shutdo~n means 8 is addressed both generally and specifically.
To summarize the automatic steering means 4, it include5 the following functional components: a row locating means 60 (Figures 1 and 8), a monitorins means 61, ~nd a s~eering control means, which comprises a 10 pivot position monitoring means 62 and a pivoting control means 63 (Figures 5 and 6). As shown primarily in Figures l through 3~ the row locating means determines ; the relative loca~ions of the machine lO~ in particular, as shown in Figure~ l and 3, a fixed alignment location 15 or centerline 64 of the machine 10, and the row axis 17.
In effect~ as Figure 3 shows best, the row location means 60 measures first and second row locating ~uantities A and B that) respectively, are distances from the centerline 64 to the ~irst and second lateral rvw 2a indices l~ and 16~ The monitoring means 61, shown best 1 in Figures 4 and 6, performs multiple functions as part i of both the au~omati~ s~eering means 4 and the automatic machine shu~down means 8: it monitors the location of the machine 10 relative to the row 12, as indicated by the row locating quantities A and B, for automatic steering purposes; also, it monitors displacement signals i senerated by displacements of row locating members caused by the indices 15 and 16, or automatic shutdown purposes. To focus on automatic steer ing, whereas the row locating means 60 communicates the quantities A and B
to the monitoring means 61, the monitoring means 61 uses .

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the guantities A and B to identify first or second ~urn conditions that e~ist, respectively, when the align~ent location 64 is spaced laterally more than a predetermined distance from the row axis 17 on the first or second sides of the row 12, respectively. In accordance ~ith a feature of the invention, the turning means 28 has first and second pivot limits, which are angularly displaced on vpposite sides from a straight ahead alignment axi~ ~to be discussed in connection with the pivot limits in the text below). The monitoring means 61 imparts to the steering control means turn condition signals indicating the existence of the irst or second turn conditions; in response to these signals, the steering con~rol means, hhich is operably connected to the steerable wheel 28, position the steerable wheel 28 at the firsS or second pivot limits, that is, when the first or second turn conditions, respectively, exist, the steerable wheel 28 turns fully to the first or second pivot limits, respectively. The pivoting contrvl means 63 ~which ~igure 6 illustrates) initiates pivo~ing of the turning means 28 toward one or the other of the pivot limits and ceases the wheel's 28 pivoting when the limit is reached.
The pivot position monitoring means 62 ~which is shown primarily in Figures 5 and 6), which communicates operatively with the pivoting control means 63 monitors the position of the steerable wheel 28.
~ aving described in general terms basic components ~ithin the automatic steering means 4, the discussion now turns ~o a detailed description of these components. To commence with a description o the row locating means 60, illustrated mostly in Figures 1 through 3, the mean~ 60 . . . .

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first includes a row locating assembly 72 for measuring the row locating quantities A and B by engaging the first and second lateral row indices, respectively, with firs~
and second row locating members 88 and 89 which the indices 15 and 16 displace laterally upon such engagement. Two row locating assemblies 72 are positioned in a forward part and on either side of the enclosure 18. Each of the two assemblies 72 positions its row locating member 88 and 89 parallel for lateral engagement therebetween with the two indices 15 and 16.
Two locating shafts 90 rotate in response to lateral displacement of the locating members 88 and 89 to indicate a displacement o~ the row locating members &8 and ~9. As Figure 2 shows best, each of the two locating shafts 90 is mounted rotatably to a xelated one of the two sidewalls 56 by a plurality of mounting means 91. A
rearward end 92 of each row locating member 88 and 89 connerts hingedly to a rear supporting link 96, and each rear link 96 connects fixedly to one of the two locating ~0 shafts 90, th~s linking mechanically each row locating ;l member 88 and 89 to its related shaf t 90. Two forward supporting links 100 each connect hingedly to one of the two row locating members 88 and 89 forward of the rear links 96. ~ach rear link 100 is connected hingedly to its related sidewall 56 by a mounting means 104.
Figure 3 shows best the configuration of the row locating members 88 and 89. Each row locating member 88 and 9 has a forward portion 108, a middle portion 112, and a rearward portion 116. A forwardly and ou'cwardly curve~
30 conf iguration of each forward portion 108, as shown in Figure 3~ is intended to prevent jamming of the !

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1~3~7 components of the machine 10 when the machine 10 encounters plants in the row 12. ~he middle portions 112 both align parallel to the two ~idewalls 56. Each rearward portion 116 in practice aligns with its related 5 middle portion 112, as sh~wn in Figures 1 and 3. As Figures 1 and 3 show, the ~ow locating members 88 and 89 are suf f iciently long in relation to distances between tl e index portions 13 of the plants in the row 12 so that the row locating members 8~ an~ 89 engage at least two of 10 the portions 13 at a time. The two forward portions 108 of the members 88 and 89 define a rearwardly converging throat 124 which rece;ves plan~s of the row 12 as the plants enter the enclosure 18. As mentioned, the row loca~ing assemblies 72 sgrv~ to i~e~p the members 88 15 and 89 parallel to the two sidewalls 56 and to mount the locating members 88 and ~9 fvr rearward and outward displacement as the members 8B arld 89 engage the ro~
indices 15 and 16. This is accomplished by two par21lel linkages as follows. Each of the row locating members 88 20 and 89 and one o~E the ~cwo Tear linlcs 96, sidewalls 56, and forward links 100, define a parallelogram 128: hence parallel linkages. (Figure 3 illustrates only one of the two parallelograms 123, namely, the one correspondin~ to member 88. ) As each of the row locating members 88 and 89 moves rearwardly and o~twardly, this displacement of that row locating member ~8 or 89 rotates its related locating shaft ~0. Such rota~ion o the locating shafts 90 is a function of the rearward and outward displacemen~ of the row lo~ating members 88 and 89.
30 ~esilient means, which is illustrated in Figure 1 an~ 3 as two spr ings 132 conne~ted be~ween a related one ~f the ,` .

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fosward links 100 and the forward members 52, cause. the row locating assemblies ~o press externally on the sides Of the row 12. When the row 12 is absent, the assemblies hold the members 88 and 89 in a neutral position 133, 5 shown in Figure 1.
Figures 1~ 3, and 4 illustrate the row monitoring means 61 which communicates with the row locatins assemblies 72, just described, to monitor the location Of the machine 10 in relation to the row 12. This is accomplished by the monitoring means 61 sensing the displacement of the row~locating members 88 and 89, causing it to impart the turn condition signals to the pivoting control means 63. As Figure 4 shows, first and se~ond parallel monitoring bars 141 and 142 define therebetween a monitoring pathway 148. The monitoring bars 141 ~nd 142 perform dual functions because they register the displacements o the locating members 88 and 89 caused by engagement with the indices 15 and 16, thus monitoring the location guantities A and B that indicate the machine's 10 lateral position, and they also indicate the displacement signals, i,e., the displacements of tbe locating members 88 and 89, for automatic machine shutdown purposes. ~o turn the discussion to the monitoring bars' 141 and 142 functions 2S in automa~ic steering, ~hey cooperPte with a monitoring wheel, tO be described shortly to find the difference between the quantities A and B, ~hereby monitoring the first and ~econd turn conditions. The first monitoring bar 141 is slideably mounted for linear extension 3D ~iovement in a first monitoring direction 152 and for retraction in a second monitoring direction lS6. The /

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~323~'7 second monitoring bar 142 is similarly mounted to be able to extend in the second monitoring direction 156 and to retract in the first monitoring direction 152, the motions of the two bars 141 and 142 being independent.
To enable the first and second monitoring bars 141 and 142, respectively, to communicate wi~h the first and second locating members 88 and 89, the first and second monitor ing bars 141 and 142 are respectively linked mechanically to a related one of the locating shafts 90 via first and second locating-monitoring communication linkages 160 and 164, shown best in Figure lo Each of the two locating~monitoring communication linkages 160 and 164 comprises a crank arm 1~8~ which serves as ~
crank attached fixedly to one of the locating shafts 90, and a crank-monitoring c~upler 170 which connects hingedly to a related one of the two monitoring bar~ 141 and 142. Each crank arm 168 connects hingedly to its related crank-monitoring coupler 170. Consequently, outward, rearward displacement of the ~irst and second row locating members ~8 and 89, respectively~ extends the first and second monitoring bars 141 and 142, respectively, ~rom their neutral positions in the first and second monitoring directions 152 and 156. When the first and second row locating members 8B and 89 are displaced inwardly and forwardly, the process reverses:
the respective first and second mon;toring bars 141 and 142 retract, with the first m~nitoring bar 141 retracting in the second monitoring direction 156, and the second m~nitor ing bar 142 retracting in the first monitoring direc~ion 152.

: , ;, 22- 1323~7 As Figures 4 and 8 show, a ~.onitoring wheel 172 positioned between and engaged with the two monitoring bars 1~1 and lq2 senses differences between the displacements of the first and second row locating bars 88 and 89. As figure 4 shows, the wheel 172 is a toothed gear 172 and the monitoring bars 141 and 142 are toothed racks 141 and 142, which engage the teeth of the gear 172. As Figure 8A shows, assuming the exteneion of the first monitoring bar 141 from its neutral position in the first monitoring direction 152 is greate;r than the extension of the second monitoring bar 142 rom its neutral position in the second monitoring directiofl 156, then the monitoring wheel 172 is displaced from a neutral position 174 (in the monitoring pathway 148) in the first monitoring direction 152. As Figure 8B shows, if the extension of the second monitoring bar 142 in the second n.onitoring direction 156 is greater ~han the extension of the ~irst monitoring bar 141 in the first monitoring direction 152, then the monitoring wheel 172 is displaced from its neutral position 174 in the second monitoring direction 156.
As Figures 8C, 8D and 8E respectively show that a disposition of the monitoring bars 141 and 142 in their neutral position, a minor equal displacement of the ba.rs 141 and 142, and a substantial equal displacement of the bars 141 and 142 all leave the monitor ing wheel 172 in its neutral position 174. In Figure 8C, 8D and 8E, the steerable wheel 28 has remained angularly displaced from its straight ahead position; this is because the 30 automatic steering means 4 causes the steerable wheel 28 to move from a pivot limit location in which the , . - :
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~ 3 ~ 7 s~eerable wheel 28 is found only when the turn condition changes, that is, only when the monitoring wheel l,2 has .oved from one side of its neutral position 174 to the other side thereof. Hence, in the Figures 8C, 8D and 8E
5 the wheel 28 will not pivot from the position in ~hich it is shown until the monitoring means 160 registers a change in the turn condition.
As Figure 4 shows best, to mount the components of the monitoring means 61 operably, ~here are provide~ a bar-shaped movable housing 176, in which the monitoring wheel is pivotally mounted for engagement wi~h the ~.onitoring bars 141 and 142, and a fixed housing 164, in which the monitoring bars 1~1 and 142 and t.he movable housing 176 are mounted slideably ~or mutually parallel, lateral back and forth movement. The movable housing 176 supports and guides the monitoring wheel 172 and it activates row monitoring switches described immediately below in connection with the turn condition signal. For pivctal mounting of ~he wheel 172 in the movabl~
housing 176, ~he wheel 172 is ~onnected to a pivot pin 186 connected pivotally to the housing 176. To guide the movable housing so as to maintain parallel rela~ion thereof with the monitoring bars 141 and 142, ~he stationary housing 184 provides a guide member 188 with a longitudinal straight edge 1~9 along which the mova~le housing 176 runs. A longitudinal channel 190 with two sides 191 in the fixed housing 189 enables the monitoring w~.eel ~72 to move freely back and forth.
To generate turn condition signals tha~ indic~e the e~istence of the first or second turn conditions, respectively, first and second row monitoring , .: - .

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shitches 201 and 202 are provided, as Fig~re 4 shows, these being supported by and positioned in the fixed housing 184. The method by which the monitoring means 61 senses a difference in the displacements of the row locating members 88 and 89, and thus the existence of the first or the second turn conditions, includes these Steps the difference in the displacements of the row locating members 88 and 89 appears as a difference in the displacements of the moni$oring bars 141 and 142 from their neutral positions which causes a displacement of the monitoring wheel 172 from its neutral position 174 in the f irst or second monitoring directions 152 and 156~
respectively, indicating the existence of the first or second turn conditions. As Figure 4 shows, the first and second monitoring switches are activated by the movable housing 176 in a manner such that activa~cion of the first or second switches 201 and 202, respectively, indicates displacement of the monitoring wheel 172 (and the muvable housing 176) from the neutral position 174 in the first or second monitoring direc~ions 152 and 156.
In discussing the generation o~ turn condition signals ~urther, details about the nature and the positioning of the switches 201 and 20~ are addressed.
In terms of their nature, the switches 201 and 202 are proximity sensing switches which sense the proximity of the movable h~using 176: a preferred one of several possibilities is ~o use metal proximity sensing switches.
As for the positioning of the switches 201 and 202, a sufficient distance should be provided between the switches 201 and 202 and the movable housing 176 in its neutral position to prevent both of the switches 201 ~' ' ' . ' S,, , .
`: :
',' ' ' , ~.

-1323~7 and ?02 from sensing the movable housing 176 a~ the same ti~e: preferably, the s~ ches 201 and 202 should be located quite close to the movable h~sing 176 in its neutral position 174. Presumably, this distance should be about one thirty-second of an inch; a greater distance delays the row monitoring switches 201 and 202 's responses to displacements of the movable housing 176.
Referring still to Figure 4, the movable housin9 maintains sensory contact with either one Gr the other Of the two switches 201 and 2020 hence, the movablQ
hou~ing 176 should have a sufficient length 192 to prevent the movable hol~sins 176 from losing sensory contact with the switches 201 or 202 as the movable housing 176 moves back and forth.
~o correct the location of the machine 10 laterally relative to the row 12, as Figure 5 shows, the steerable wheel 28 has a first pivot limit 211 and a second pivot limit 212. As Fi~ures 1 and 3 show, when the steerable wheel 28 is at the first or second pivot limits 211 and 212, respectively, it turns the machine 10 toward f irst or second sides 213 and 214 of the machine 10 (corresponding respectively to the îirst and second row locating members 88 and 89). For purposes of illustration; Figure 5 shows an alignment axis 218 25 representing the directiorl in which the machine 10 is traveling when moving alvn~ the row 12. The f irst and second pivot limits 211 and 212 of the steerable wheel 28 are angularly displaced on opposite sides from the alignment axis 218.
30 ~ To enable pivoting of the steerable wheel 28 to halt when the steerable wheel 28 has attained either the f irst ~ ............. . . . .
.~ .

,: .

~323~

or second pivot limit 211 and 212, the pivot position monitoring means 62 shown in Figure 5~ imparts a limit signal to the pivoting control means 63 that halts pivoting of the steerable wheel 28 and keeps the wheel 28 5 positioned ~t the first or second pivot limits 211 or 212u The pivot position monitoring means 62 comprises a movable angular displacement indicator 220 which pivots wi~h the steerable wheel 28 and first and second limit s~itches 223 and 224 fixed to the chassis 20~ The 10 ang-~lar displacement indicator 220 activa~e~ ~che first or second limit switches 223 and 224, respe~tively, when the steerable wheel 28 is at the f irst Ol second pivot limits 211 or 212. Inasmuch as the angular displacement indicator 220 is an arc-shaped member fixed to a pivotable part of the mounting means 36 for the steerable wheel 28, it travels through an angle, which includes the first and second pivot limits 211 and 2120 As it pivots, it describes a path. The first and second limit sh~itches 223 and 224 are positioned adjacent to that path in a manner such that the first or second limit . s~itches 223 or 224, respectively, are activated when the , steerable wheel 28 is at the first or second pivot j limits 211 or 212.
~t is to be noted that the steerable wheel 28's pivotable mounting means 36 comprises elements as shown in Figure 2A: a member 225 which connects to an end 226 of a transverse axle 227 of the steerable wheel 28 on which the wheel 28 rotates; a vertical pivoting pin ~29 which is ~ixedly attached to the member 225 and which 30 enables the pivotable mount 36 to pivot about the vertical axis 38 of the steerable wheel 28~ connected ..

.. . .

, ~ ' ., ~ ,. . ~ . ~

~323~7 f ixedly to an upper portion of the member 225 and pivotally to the chassis 20 by a pivotal mounS 230~ The first and second limit switches 223 and 224 are fixed to the machine 10 while the angular displacement indicator 220 (visible in Figure 5) is fixed to a mov~ble pivoting component, such as the piYOting pin 229, of the pi vo table mol~nt 3 6 .
To pivot the s~ceerable wheel 28, there is provided a pivoting drive means 231, shown in Figure 5, which 10 compr ises a ~onventional hydraulic dr ive cylinder 232 with one end f ixed to the machine 10, a jack arm 240 and a pivot lever 244 operatively connected to the steerable wheel 28. As Figure 5 ~hows, linear retraction or extension, respectively, of the jack arm 240 in the cylinder 232 moves the steerable wheel 28 toward the first or second pivot limits 211 and 212.
As shown in Figure 6~ a control circuit 272 is operatively connected to the main harvesting eq~ipment 19 (of Figure 1) in the machine 10, equipment for 20 automa~ically steering, and automatic machine shutdown equipment. The control circuit 272 comprises three subcircui~s. Firsty a coordination circuit 273 assures that the a~tomatic steering 4 and the automatic shutdown 8 operate only when the main harvesting e~ipment 19 is on, Second, an automatic steering control circuit 274 transmits tS~e turn condition signals fron the row monitoring means 61 and the pivot position monitorinq means 62 to the pivoting con~rol means 63 thereby enabling the means 63 to control pivotirlg of the 30 steerable wheel 28 to pivot in response to the relative locations of the machine 10 and the row 12. Third, an ,~::, ., , - . , . .. : ,, :

1323~P~ ~

automatic machine shutdown circuit 275 responds to signals from the automatic shutdown system 8. Electric power is supplied from an electric power source 280 directly to the coordination circuit 273 and indirectly, via the coordination circuit 273 and a power line 284, to the automatic steering control clrcuit 274 and the au~omatic n,a~hine shutdown circuit 275.
Before turning the discu~sion to the details of the individual subcircuits, it is to be noted that the piv~ting control means 63 of the automatic s~eering means 4 compr ises essentially a contrc~l valve 276, shown in Figure ~, which is to be discussed below in connection with the automatic ~teering control circuit 274.
To describe the co~rdinating circuit 273, as shown in Figure 6, a positive terminal of the electrical power source 280 connects through a main power switch 292 and a line 296 to an electric solenoid which activates the operating equipment 19, such as the beater rods that engage the crop row 12 to remove the product therefrom~
The main on/off switch 292 and ~ coordinating on~off st~itch 300 must both be closed in order for the re~.aining circuits of the control circuit 272~-i.e., the automatic steering circuit 274 and the automatic machine shutdown circuit 275--to operate. This is because the power 25 source 2P~0 connects in series via the main on/off shitch 292, a line 301, and the coordinating on/off sh~itch 300 to the remaining circuits 274 and 275.
Before describing in detail the circuitry 2ï4 for 'che automatic steering, more details of the electrically 30 actuated control valve 276 of the automatic ~teering means 4 are provided, referring still to Figure 6. The ',;: :
. .

. : : : . :
;: ~ , .
,, ~: :

1323~

control valve 276 connects operatively to the pivoting drive means 231 to cause the steerable wheel 28 to do three thinys: pivot toward the first pivot limit 211, cease pivoting, or pivot toward the second pivot limit 212. The control valve 276 comprises a main valve element 306 having a reverse flow ~ection 307, a middle, off section 308, and a forward flow section 309, the three sections 307, 308 and 309 of the element 306 being selectively connected to the hydraulic cylinder 232 to direct hydraulic fluid in a manner to control the pivoting of the steerable wheel 2~ as described~ First and second solenoids 311 and 312 are operatively connected to opposing ends of ~he control valve 276 to magnetically draw the element 306 in opposing directions.
~ence~ as F~gure 6 shows, energization of the first or second solenoids 311 or 312, respectively, draws the element 306 so as to align th~ sections 307 or 309, respectively, for reverse or forward flow, respectively, of pressurized fluid, which initiates pivoting of the steerable wheel 28 toward its ~irst or second pivot limits 223 or 224, respectively. When the current is off, neither of the solenoids 311 or 312 draw the element 306. Accordingly, resilient means in the control valve 276 positions the element 306 so that the off 25 section 308 thereof is aligned to stop ~Elui~ flow, causing pivoting of the steerable wheel 28 to cease. The solenoids 311 and 312 are grounded by two separate grounds 314.
To describe the automatic steering contr~l circuit 274, as discussed previously in connection with the turn condition signals, the monitoring means 61 , , : . , . -:: . : -` ~ :

1323g~

includes ~he first and second row monitoring switches 201 and 202 as shown in Figure 6. In the circuit 274, the row monitoring switches 201 and 202 are normally openO
The circuit 274 also includes the two limit switches 223 and 224, also discussed previously in connection ~ith the pivot position monitoring means 62, tha~ are normally Closed. As Figure 6 shows, in the circuit 274, the first and second row monitoring switches 201 and 202, respectively, are co~nected in parallel via the first and 10 second limi~ switches 223 and 224, respectively, to the first and second solenoids 311 and 312 of the control valve 276, respectively. That is, the power line 284 sives power to the two row monitoring switches 201 and 202 via two separate branch lines 315; then, the 15 ~ir~t row monitoring switch 201 connects, via a line 348, the first limit switch 223, and a line 352, to the first solenoid 311; the second row monitor ing switch 202 connects, via a line 356, the second limit switch 224, and a line 360, to the second solenoid 312.

2~ Additionally, the following points ase to be noted: the control valve 276 receiYes pressurized hydraulic fluid from a fluid source 316 and it returns hydraulic fluid to a fluid reservoir 320; the control valve 276 connects operatively via two separate hoses 324 and two separate 25 ports 328 of 'che cylinder 23? to opposite sides of a piston 336 within the c:ylinder 232.
Elaving described ~Lhe au~omatic steering circuit 274, operation of tl-e automatic ~teering means 4 using the automatic steering circuit 274 is now addressed,. In 30 operation, the automatic steering means performs as ~ollows. As ~hown in Figure 8C, when there is no row 12 .
.:

, ~ , ~L323~7 between the locating ~embers 88 and 89, the members 8e and 89 are nearly toge~her~ As Figure 8D shows, and as mentioned previo~sly, introduction of the row 12 displaces the sensing members 88 and 89 ou~wardly and rearwardly. As Figure 8A shows r and also as previously mentioned, assuming that the machine 10 is steered too far with respect to the row 1~2 ~oward the machine 's side corresponding to the second row locating member 89, the displacement of the first row locating member 88 exceeds the displacement of the second rvw lpcating member 89. Consequently~ as Figure 6 shows, the monitoring means 61, by closing the first row monitoring switch 201, imparts the tusn condition signal to the control valve 276 for initiating pivoting movement of the steerable wheel 28. This energizes the first solenoid 311 ~f the control valve 276 which directs pressurized fluid to the cylinder 232 of the pivoting drive means 231 retracting the piston arm 240 and pivoting the steerable wheel toward the first pivot limit 211. Referring still to Figure 6, when the ~teerable wheel 28 reaches the first pivot limit 211, this opens the Pirst limit ~witch 223, breaking the circuit to the f irst solenoid 311, which aligns the section 308 of the valve element 306 to stop fluid flow ceasing the pivoting of the steerable wheel 28.
~eturning to Figure 8A, this le~ves the steerable wheel 28 at the first pivot limît 211 (the sequence just described, including this attitude 211 of the steerable wheel 28, is also shown in Figure 3), then, the machine 10 steers toward its first side 213 which brings the centerline 64 of the machine 10 back toward the row .... . .. ..

.

1323~87 axis 17 of the row 12. Assuming that the centerlin~ 64 of the machine 10 crosses the row axis 17 making the machine 10 off-center to the opposite side 15 of the ro~ 12, in a sense there occurs a mirror image of the above-described sequence, as Figure 8B indicates.
Because the subsequent steps axe identical to the described steps; further detailed description of those steps is deemed unnecessary, except to note that the steerable wheel 28 assumes the second pivot,limit 212, as shown by the at~itude 212 of the steerable wheel 28 in Figure 8B, and turns the machine 10 toward its second side 214, thus brining the centerline 64 of the machine 10 back to the row axis 17.
As Figure 7 shows, in the machine's 10 normal 15 operation, it describes a path 368 that consists of a plur~lity o~ alternating first turns 371, during which the steerable wheel 28 is at the first pivot limit 211 and the machine 10 steers toward its first side 213, and second turns 372, during which the steerable wheel 28 is 20 at the second pivot limit ~12 and the machine 10 steers to-~ard its second side 214. In short, the machine 10 experiences a cyclical steering pattern charactelized by repeated turns.
Before turning to a description of the automatic 25 machine shutdown ~ean~ ~ ;t is thought that supplementary information will assist the reader. In harves~ing berries, berry plants may be grouped in a plurality of ~hills" 376, which Figure 7 shows, in effect tight groupings of individual vines which are estilr,ated 30 to be roughly 30" apart. ~bese steering cycles of the machine can be quite regular, cycling completely between , , ~

'.':; - ' ' ' ~ "

~323987 the first and second turns 371 and 372 about once for every two hills, or it may be ~hat the machine 10 will travel a longer distance before initiating a new turn.
It is to be noted that an angle which Figure 5 shows S between the first pivot limit 211 anù the alignmen~
axis 218 and an angle be~ween the second pivot limit 212 and the alignment axis 218 should ~e within the ~ollowing range. These angles should be sufficiently large, considering the speed of the ma~hine 10, to provide adequate correction of steering errors~ In practice with berry harves~ing the bersies being planted in the descr ibed hills 376 of Figure 7~ a minimum angle o three degrees from the ali~nment axis 218 can provide an adequate correc~ion capa~ y a~ a speed of 15 one-and-one-half miles per hour. Additionally, these angles should be suffici~ntly sm~ll to give the steerable wheel 28 adequate time ~o rotat~ ~etween the pivot limits 211 and 212 befo~e a new change in the ~urn condition occursO It is ~stimated that a maximum angle 20 of f ive degrees between the pivot limits 211 and 212 and the alignment axis 218 is appropriate. This is a correctiorl on the order of about 2" for a travel ing distance along ~he row ~f 307' ~2.1" = 30" x tan 4).
Also, with many kinds of plants such as berry bushes 25 or vines, the stem portion 13 of the plant is usalble as an index for automatic steering guidance.. E(ow locating members 88 and 89 are adaptable to different kinds of indices, which provide the basic dual, lateral indices 15 and 16 which the present invention employs., As Figure 2 30 shows, with plants having stem p~tions usable as indices, the row locating mem~ers 88 and 89 should be - ; , : .
:, - ' , . . ': ' ':. , : ,.,'' . , ': .

~323987 positioned lo~ eno~gh so that they engage the stem portion 13 rather thar, the foliage portion F.
Additionally, as Fig~re 1 illus~rates, when ~he row locating assemblies 72 are in their central, neutral positions 133, the ro~ locating members 88 and 89 should be sufficiently close to one another to assure that they respond to plants of the smallest diameter in the row 12.
For instance, with berry plants, when the row locating assembly 72 is in i~s neutral position 133, the row locating members 88 an~ B9 should be about ~ne inch apart.
As indicated i~ Figure 3~ the capacity o~ the automatic steering means to aacommodate the widest plants depends upon the capacity of ~he resilient means 132 to extendl the freedom of the row locating members 88 and 89 to move outwardly and rearwardly~ the width a passageway 391 def ined between two crop receiving hoods 398 f ixed to the iEorward end of the ohassis 20 of the machine 10l and a capacity ~r lateral movement of 20 the row monitori~g wheel 172 and the movable housing 176.
In berry harvesting, the lateral displaoement c3pacity of each row locating member 88 and 89 believed necessary from the alignment location ~4 of the machine ;s about eleven inches, If an aberration, such as a stray rock, ~omes in the path of the row locating members 88 and %9, assuming such an aberration displaces only one of the row loca~ing members ~8 and 8g~ as ~igure 8F shows5 the automatic steering means 4 auto~T.atically limits its ~ensitivity to 30 the aberrationO Ina~ltuch as the row monitoring wheel 172 is displaced only half an amount of displacement as one :` .
!; ' ' ,~. .
' . .

~3~3~87 of the monitoring bars, ill~stra~ed as the second ro~
monito~ing bar 142, the sensitivity of the row monitoring wheel 172 to the aberration is lessened.
Figures 4, 6 and 9 best illustrate the automatic machine shutdown means 8. The automatic machine shutdown means utilizes displacement signals generated by the automatic steering means 4, indicating displacement of the row locating members 88 and 89, to sense the presence or the absence of the row 12. As discussed previously in connection with the monitoring means' 61 multiple functions, the means 61 indicates these displacement signals by linear movement of the first and second monitoring bArs 141 and 1~20 A displacement signal sensing means 400, indicated in Figure 4, senses these movements of the irst and second moni~oring bars 141 and 142, and imparts displacement signals ~o a machine shutdown means described below. The machine shutdown means monitors time which elapses between the displacement signalsO Then, if a predetermined amount of time elapses without any displacement signals occurring, the machine shutdown means halts the operation and the locomotion of the machine 10.
To sense the displacement signals, the displacement signal sensing means 400, as Figure 4 shows" comprises a plurality of displacement sensing switches described shortly. As they move back and forth/ the first and second monitorinq bars 141 and 142 describe linear paths 408 comprises in Figure 4. The displacement sensing means 400 locates a plurality of displacement sensing switches 415 located adjacent to the paths 408 of the first and second monitoring bars 141 and 142 in a :: , ~ 323~7 r,anner such that the switches 415 sense any displacement of ~he first and second row locating bars 88 and 89 occurrir~g. Proximity of the first and second row monitoring bars 141 and 142 to the displacement signal sensing switches 415 activates the switches 415~ A
preferred one of several possibilities is for the first and second monitoring bars 141 and 142 to comprise metal and the displacement signal sensing switches 415 to be metal proximity sensing switches.
To halt the movement and operation of ~he machine 10, there is a machine interruption means, which Figure 9 illustra~es. Figure 9 shows a hydraulie locomotion and operation system 422 for the machine 10.
A hydraulic pump ~24 provides pressurized hydraulic fluid to operation components 428 and locomotion components 432 of the machine 10. Operation components 428 include means for carrying out certain operations of the machine 10~ such as belt-type produce catching system used in harvesting~ Machine locomotion components 432 propel the machine 10. A machine interruption means 43 shuts off the flow of pressurized hydraulic fluid ~o the operating components 428 and the locomotion components 432 thereby halting the operation and locomotion functions. A ~luid artery 440 provides pressurized fluid from the pump 424 to the operating components 428 and the locomotion components 432. Fluid return means 444 returns hydraulic fluid from the operating and Iocomotion components to the pump 424. The interruption means 436 which is electrically activated, simply connects the fluid artery 440 directly to the fluid return means 444~ completely bypassing the :.
~ , ,~.~. ., ~ , . .
.

, 1323~7 operation components 428 and the locomotion co3ponents 43~.
The automatic machine shutdown circuit 275 of Pi~ure 6 enables the displacement signal sensing 5 s~-itches 415 to communicate operably with a machine s~n~tdown means 472. The machine shutdown means 472 co~prises the operation locomotion interruption ~,eans 436, just described, and a clock means 476. The clock means 476 measures time which elapses between the occurrence of displacement signals. If a predetermined a~ount of time elapses wi~hout any displacement signals occurring, the clock means 476 activates the operation lo_omotion interruption means 436. A line 480 enables the clock means 476 to communicate with, and activate, tt.e operation locomotion interruption means 436~ The clock means 476 activates the interruption means 436 when the clock means 476 receives electric power continu~usly for the predetermined amount of time. An interruption in the power supplied to the clock means 476, resets the cl~ck means 476. The displacement signal sensing s~itches 415 are normally closedO Accordingly~ if the predetermined amount of time lapses without a displacement signal occurring t ~he displacement signal sensing switches will allow power to be conducted through the automatic machine shutdown circuit 275 continuously tc the clock means 476.
The automatio machine shutdown circuit 275, as Fi_ures 6 shows, is wired to respond to displacement si^nals as follows. The two displacemen~ signal sensinq s~itches 415 are wired in series to the electrical power so~rce 280; the machine shutdown means 472 and the 1 3~239~
displacement signal sensing switches 415 are also connected in series. In detail, the two displacement signal sensing switches 415 are mutually connected by a line 496. One of the displacement signal sensing switches 415 connects directly to the power line 284; the other displacement signal sensing switch 415 connects ~o the machine shutdown means 472 by a line 482.
Additionally, the automatic machine shutdown circ~it 275 includes supervision assurance means 484 for assuring that the operation and locomotion functions of the machine will operate only with the supervision of a human attendan~. If a human attendant is absent from the attendant's portion 40 o~ the machine 10, shown in Figure 1, then the supervision assurance means 484 actuates the machine shutdown means 472. The supervision assurance means 484 includes an attendant sensing s~itch 488, which for example could be placed at the chair on which the operator sits, with the swi~ch opening when the operator is positioned in the chair. Electric po~er source 280 connects via the power line 284, a line 504, the switch 488, a line 50~, and a line 482 to the machine shutdown means 472. Absence of the operator from the chair closes the switch 488 immediately actuating the machine interruption means 436.
To enable the supervision assurance means 4B4 to actuate the machine shutdown means 472, these two co.~ponents are connected in series to the power source.
Appropriate ground means 492 ground the machine shutdown means 472.
If the operator is not in the chair, the switch 488 closes supplying power to the machine shutdown means 472.

.: :

. . . . .
.
.
~' , ~323~7 It is to be noted that the switches 415 are positioned sl~ff iciently close to the bars 141 and 142 so that any significant touching of the members 88 and 89 and the row 12 will activate the switches 415.
It is to be understood that a number of variations of automatic machine shutdown means, which address the problems described herein, can be adap~ed for use ~ith automatic steering methods and systems, inasmuch as these methods and systems generate displacement signals or other indications of the presence and absencj~ o~ the row 12.
Assuming that either of the monitoring bars 141 and 142 moves from its neutral position within the predetermined amount of time, then the automatic machine shu~down circuit 275 will deliver no electricity to the operation locomotion interruption means 436. If both of the monitoring bars 141 and 142 remai~ in their neutral positions for the predetermined amount of ~ime, then the displacement signal sensing switches 415 will remain closed, power will be supplied to the interruption means 436, and the operation and locomotion of the machine 10 will halt.
The predetermineid amount of time should be selected to provide prompt halting of the machine 10, assuming that the machi~e 10 is at the end of the row 12.
Sometimes there are headlands which allow a margin of safety at the ends of the rows 12~ ~owevrr, in other cases irrigation ditches are close to the ends of the rows 12. The time should not be so short that a ~.inor hiatus in the row 12, such as a pathway, triggers a ,. . .

~323~

shutdown. In certain circumstances, then, an appropriate ti~e is two to five seconds.
Figure 10 summarizes an embodiment of logic which ~h~ invention uses. In Fiyure 10, various triangle~
represent decisions, upon which ~che alltomatic steering means 4 and the automatic machine shutdown means 8 act.
According to triangle 512, if there is no attendant in the machine 10~ then the chassis 20 halts. If an attendant is presen~, ~hen the next ~eeision represented by triangle 51S is addressed. ~ccording to triangle 516, if a predetermined amount of time7 which is illustrated as two to five seconds, elapses without any contact Gccurring with the row 12, then the chassis 20 halts. If contact signals occur more PrequentlyJ then the logic proceeds to an automatic steering ~tage 520. The automatic steering stage 520 comprises a fir t branch of logic 524 and a second branch of logic ~280 Under the ~ranch 524, there is an initial decision represented by a triangle ~320 AccoYding to triangle 532, if the chassis 20 i~ on cen~er, then no steering ~orrection is ~ necessary. If the chassis 20 is off to the left of center, then ~he logic proceeds to a decision which triangle 536 represents. If the steerable wheel 28 is less ~han a predetermined angle, which is illustrated as five degrees, rom straight, then the invention keeps t~rning the steerable wheel 28 to the righ$. If the steerable wheel 2B has rotated an angle of five degrees from straight (meaning that the wheel 28 is at a first or second pivot limit 211 and 212 o~ Figure S) 9 then the wheel 2B stops pivoting. Under the second branch 528, the logic initially decides whether the chassis 20 has ': .
. . - ~ .
.~ . ..................... - : ' ,. . .

-41- ~323987 s~eered off to the right of center as represented in triangle 540. If it has not, then no correction is neceSsary~ I~ it has, then the logic proceeds to another decision shown as triangle 544. If the steerable ~heel 28 is less than five degrees from straight, then the wheel 28 keeps pivoting to the lefta If the wheel 28 has rotated an arc of five degrees ~rom straight, then the steerable wheel 28 stops pivoting.
In summary~ the invention senses and monitors the position of the row 1~ with respect to the ~achine 10 ~ith entirely mechanical, non-hydraulic meansD Because it accoun~s for varia~ions in ~he thickness o plants in the row 12, it is self-sufficient~ The inventior, also monito~s the presence of the row to guard against overrunning of gaps in the row. Also, it elimin2tes steps required to correlate a corrective rotation of the steerable wheel 28 to a quantity of steering error.
In harvesting berries, the invention steers the chassis 20 sufficiently close to the row 12 to masimize the retrieval of berries during berry harvesting.
From the ~oregoing, i~ is apparent that this invention is one well adapted to attain the objects set forth above, together with o~her advantages. It is to be understood that various modi~ications could be ~ade to the present invention without departing from the basic teachings thereof.

,:

Claims (20)

1. A crop tending machine adapted to travel along a crop row having a crop row axis and firs and second sides oppositely positioned relative to said crop row axis, said machine comprising:
a. a chassis arranged to travel along said crop row axis, said chassis defining a crop engaging region with an alignment location which is desirably in alignment with said crop row axis during operation of said machine;
b. location sensing means responsive to location of said machine relative to said crop row axis and arranged to provide an output related to distance of said alignment location from said crop row axis;
c. steerable wheel means mounted to said machine so as to be movable between first and second turning position in which said steerable wheel means turns said machine from straight ahead travel toward the first and second sides of the crop row, respectively;
d. steering control means responsive to said location sensing means in a manner to move said steerable wheel means fully between said first and second positions in a manner to cause said machine to move in sequential curved turn segments back and fourth across aid crop row axis;
wherein said control means is arranged to respond to an input that indicates that the alignment location is on the second side of the crop row to cause said steerable wheel means to move fully to said first position, and also to respond to an input that indicates that the alignment location is on the first side of the crop row axis to turn the steerable wheel means fully to the second position;
wherein said locating sensing means comprises first and second locating members arranged to engage said crop row on first and second sides thereof in a manner to sense location of said machine relative to said crop row, said control means being responsive to a difference in distance of said first and second locating members from said alignment location to turn said steerable wheel means in a direction toward the side where the locating member is at a lesser distance from said alignment location;
wherein said first locating member is operably connected to 2 first control member responsive to distance of said first locating member from said alignment location, and said second locating member is operatively connected to a second control member in a manner to be responsive to a distance of said second locating member from said alignment location;
wherein said control means comprises a differentiating control member responsive to outputs from first and second control members to initiate a steering signal corresponding to a difference in the outputs from the first and a second locating member.

2. The machine as recited in claim 1, wherein said first and second control members comprises respectively, first and second bar means arranged to move parallel to one another.

3. The machine as recited in claim 2, wherein said differentiating control member is operably engaged to said first and second bar means in a manner that movement of either of said first and second bar means causes a corresponding movement of said differentiating control member, in a manner that equal and opposite movement of said bar means causes no movement of said differentiating control member and movement of said first and second bar means in the same direction causes movement of said differentiating control member in said same direction.

4. The machine as recited in claim 3, wherein said control means comprises first and second switch means responsive to movement of said differentiating control member in first and second directions corresponding to greater differentiating movement of said first and second bar means, respectively.

5. The machine as recited in claim 4, wherein said differentiating control means comprises a wheel means positioned between said first and second bar means, in a manner that an increment of movement of said first and second bar means in the same direction causes a corresponding increment of movement of said differentiating control means in the direction of movement of the first and second bar means, and a segment of movement of either of said first and second bar means separately causes a corresponding movement of said differentiating control means a distance of one-half of said segment in the direction of movement of the first or secind bar means, respectively.

6. The machine as recited in claim 5, wherein there are first and second shutdown switches positioned for operative engagement of said first and second bar means, respectively, said machine further comprising shutdown control means which is responsive to both of said first and second shutdown switches sensing nonengagement with both of said first and second bar means to indicate a situation where said locating members are located in closer proximity to said alignment location, and to react to stop travel of said machine.

7. The machine as recited in claim 1, wherein said control means comprises first and second steering position switches located to sense when said steerable wheel means is in said first and second positions, respectively, said steering sensing switches being operatively connected to said control means to stop turning of said steerable wheel means when said steerable wheel means has reached a position to contact either of said first and second steering sensing switches.

8. A crop tending machine having first and second sides and able to travel along a crop row having a crop row axis and first and second crop sides oppositely positioned relative to said crop row axis, said machine comprising:
a. a chassis arranged to travel along said crop row axis, said chassis defining a crop engaging region with an alignment location which is desirably near said crop row axis during operation of said machine;
b. location sensing means responsive to location of said machine relative to said crop row axis and arranged to provide an output related to distance of said alignment location from said crop row axis;
c. steerable wheel means for directing travel of said machine and mounted to said machine so as to be movable to, respectively, a first predetermined angular position or a second predetermined angular position that are angularly displaced relative to a straight ahead travel position, and which direct travel of said machine toward the first and second sides of the machine, respectively.
d. steering control means responsive to said location sensing means in a manner to move said steerable wheel means to said first angular position when said sensing means senses the location of the machine to be more toward said second crop side and to maintain said wheel means in said first angular position until said sensing means senses the location of the machine is more toward said first crop side, at which time said steering control means moves said wheel means to said second angular position and maintains said wheel means toward said second crop side, in a manner to cause said machine to move in sequential curved path segments back and fourth.

9. The apparatus as recited in claim 8, wherein said sensing means comprises first and second locating members arranged to engage said crop row on first and second sides thereof in a manner to sense location of said machine relative to said crop row, said control means being responsive to a difference in distance of said first and second latching members from said alignment location to turn said steerable wheel means in a direction toward the side where the locating member is at a lesser distance from said alignment location.

10. The apparatus as recited in claim 8, wherein said sensing means comprises first and second locating members arranged to engage said crop row on first and second sides thereof in a manner to sense location of said machine relative to said crop row; wherein said control means comprises a first locating member which is responsive to a distance of said first locating member from said alignment location and a second control member which is responsive to a distance of said second locating member from said alignment location; wherein said control means further comprises a differentiating control member which is operatively connected to said first and second control members in a manner that movement of either of said first and second control members causes a corresponding movement of said differentiating control member, in a manner that equal and opposite movement of said first and second control members causes substantially zero movement of said differentiating control member and movement to said first and second control members in the same direction causes movement of said differentiating control member in the same direction.

11. The apparatus as recited in claim 8, further comprising:
a. a row contacting means which is arranged to contact said row;
b. a gap warning means which is arranged to warn an operator of said machine when contact between said row contacting means and said row discontinues for more than a predetermined length of time.

12. The apparatus as recited in claim 8, wherein said sensing means comprises right and left sensing bar means each of which has a forward portion that curves forwardly and outwardly and middle and rearward portions that are aligned generally with a direction of travel of said machine, said sensing bar means being mounted in a manner to be maintained generally aligned with said direction of travel while being free to move laterally between a more inward neutral position and all outward position, said forward positions defining an inwardly and rearwardly converging crop receiving throat when said sensing bar means are both in said neutral position.

13. The apparatus as recited in claim 8, wherein said sensing means comprises first and second locating member arranged to engage said crop row on first and second sides thereof and said control means comprises a first control member responsive to a distance of said first locating member from said alignment location, and a second control member which is responsive to a distance of said second locating member from said alignment location, wherein said control members are used to sum said distances in a manner to indicate a misalignment of said machine more to said first side or more to said second side and are used to indicate contact between said machine and said row said contact being monitored by a gap warning means which warns an operator of said machine when said contact discontinues for a predetermined length of time.

14. The apparatus as recited in claim 8, wherein said first and second turning positions are each angularly displaced from a straight ahead steering position by an amount which is sufficiently small so as to permit said steerable wheel means to attain said turning positions before pivoting of said steerable wheel means is reversed by said control means.

15. A method tending crops which are in a crop row having a crop row axis and first and second crop sides oppositely positioned relative to said crop row axis, said method comprising:
a. moving a machine, which has first and second sides and a chassis, along said crop row axis, said chassis defining a crop engaging region with an alignment location which is desirably near alignment with said crop row axis during operation of said machine;

b. operating a location sensing means responsive to a location of said machine relative to said crop row axis to provide an output related to distance of said alignment location from said crop row axis;
c. operating a steerable wheel means mounted to said machine so as to move said wheel means to respectively first and second predetermined angular positions in which said steerable wheel means turns said machine from straight ahead travel toward the first and second sides, respectively, of the machine row in response to said location sensing means in a manner to move said steerable wheel means to said first annular position when said sensing means senses the location of the machine be more toward said second crop side and to maintain said wheel means in said first angular position until said sensing means senses the location of the machine is more toward said first crop side, at which time said steering control means moves said wheel means to said second angular position and maintains said wheel means in said second angular position until said machine is more toward said second crop side, in a manner to cause said machine to move in curved segments back and forth across said crop row axis.

16. The apparatus as recited in claim 15, wherein said sensing means comprises first and second locating members, respectively, arranged to engage said crop row on, respectively, first and second sides thereof;
wherein said control means comprises a first control members whose movement is a function of distance of said first locating member from said alignment location, and a second control member whose movement is a function of a distance of said second locating member from said alignment location, wherein said first and second control members are arranged to move along parallel paths to one another.

17. An apparatus for warning an operator of a crop tending machine, said crop tending machine having a steerable wheel means which directs travel of said machine and a chassis arranged to travel along a crop row, said chassis defining a crop engaging region with an alignment location which is desirably generally in alignment with a crop row axis of said crop row during said operation of said machine, said apparatus comprising:
a. a location sensing means responsive to location of said machine relative to said crop row axis and arranged to provide an output related to distance of said alignment location from said crop row axis;
b. a location sensing means responsive to a crop engaging means which engages said crop row so as to determine a location of said machine relative to said crop row axis;
c. a steering control means responsive to said location sensing means in a manner to turn said turnable steerable wheel means between different turning positions in a manner to correct a misalignment between a direction of travel of said machine and said crop row axis;
d. a warning means that warns an operator of said machine about a gap in said crop row when contacts between said crop row engaging means and said crop row discontinues for more than a predetermined length of time.

18. The apparatus as recited in claim 17, wherein said sensing means comprises first and second locating members, respectively, arranged to engage said crop row, respectively on first and second sides thereof;
wherein said control means comprises a first control agent which generates a first control response in response to contact between said first locating member and said first side, and a second control agent which generates a second control response in response to contact between said second locating member and said second side, wherein said gap warning means monitors said control responses.

19. A crop tending machine adapted to travel along a crop row having a crop row axis and first and second sides oppositely positioned relative to said crop row axis, said machine comprising:
a. a chassis arranged to travel along said crop row, said chassis defining a crop engaging region with an alignment location which is desirable generally in alignment with said crop row axis during operation of said machine;
b. a locating sensing means responsive to location of said machine relative to said crop row axis, said location sensing means comprising first and second locating members, respectively, arranged to engage said crop row, respectively, on first and second sides thereof in a manner to sense location of said machine relative to said crop row;
c. a steerable wheel means pivotally mounted to said machine for directing travel of said machine;
d. a steering control means responsive to said location sensing means in a manner to control said steerable wheel means so as to counteract misalignments of a direction of travel of said machine from said crop row axis, said control means comprising a first bar means which is displaced along a first bar path by an amount which is a function of a distance of said first locating member from said alignment location, and a second bar means which is displaced along a second bar path by an amount which is a function of a distance of said second locating member from said alignment location, said control means further comprising a summing means which compares displacements of said first and second bar means, respectively, along said first and second bar paths, to determine a net misalignment of direction of travel of said machine from said crop row axis.

20. The apparatus as recited in claim 19, wherein said first bar means is arranged to be displaced in a first direction along said first bar path and said second bar means is arranged to be displaced in a second direction, which is opposed to said first direction along said second bar path, which is generally parallel to said first bar path.