CA2155252A1

CA2155252A1 - Remote control system and method for an autonomus vehicle

Info

Publication number: CA2155252A1
Application number: CA002155252A
Authority: CA
Inventors: Carl A. Kemner; Joel L. Peterson
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 1994-09-01
Filing date: 1995-08-03
Publication date: 1996-03-02
Also published as: JPH0895635A; AU2830695A; AU685295B2; JP3759979B2; US5448479A

Abstract

A system and method for remotely controlling an autonomous vehicle uses a tele-panel to interrupt autonomous operation. Radio communications established between the tele-panel and the vehicle ceases autonomous operation of the vehicle and places the vehicle in a tele-ready mode in which the vehicle will not respond to commands from other tele-panels. Upon communication of a tele-operation request signal to the vehicle, the vehicle enters tele-operation mode. In this mode, the vehicle is responsive only to speed and steering angle requests from the transmitting tele-panel. A unique tele-panel identifier transmitted to the vehicle prevents other tele-panels from gaining control of the vehicle. If communications between the vehicle and the tele-panel identified by the tele-panel identifier are interrupted while the vehicle is in tele-operation mode, the vehicle is locked and will not respond to commands from other tele-panels and will not enter autonomous operation If communications between the vehicle and the tele-panel identified by the tele-panel identifier are interrupted while the vehicle is in the tele-ready mode, autonomous operation or control by other tele-panels is not prevented.

Description

Inventors: Carl A. K~mner Joel L. Peterson s Background of the Inven~on Field of the Invention This invention relates generally to the control of autonomous vehicles and, more particularly, to a system and method for remotely controlling an ~UtOl~oLuous vehicle.

RP~Ote~ Art Caterpillar Inc. of Peoria, Illinois, m~mlf~ctllres off-road mining vehicles. For example, the Caterpillar 777C is an off-road mining truck.
Commonly owned, allowed U.S. Pat. Appl. No. 08/019,540, filed re~
18, 1993, "Vehicle Position Dct~ in~lion System and l~eth~, n the full text of which is Lùcolporated herein by r~rei~cc, discloses an aulo~oLuous vehicle system for use with a mining vehicle such as the 777C truck.
Commonly owned U.S. Pat. Appl. No. (to be ~sig~l), (Attorney Docket No. 1246.0490000), filed on even date h~e~ , and titled "System for Controlling a Vehicle to Selectively Allow Operation in Either an Au~ oll~ous Mode or a ~l~ml~l Mode," discloses a system for sele~ ,ly O~ldli~lg an aulo~oLuous vehicle in an autonomous mode or m~ml~l (i.e., m~nnP~l) mode.
At times it may be desirable to provide remote-control or tele-control mode for the vehicle. In tele-operation, an opelatol could control the vehicle using a tele-panel or remote control which co,.. ~ es co~.. An~s to the vehicle via radio waves. This mode might be used, for example, by a mP~h~nir to position the vehicle within a service bay. This mode might also be used by a folcLl~ on a job site to temporarily take control of an autonomous vehicle to route it around an obstacle.

CAT Ref~ 514 SKG~F Ref: 1246.047 - 21S~252 To ensure safety, the transition periods bel~n autonomous, manual and tele-operation must be strictly controlled. Moreover, the status (i.e., who is in control) of the vehicle must always be known.

Summa y of the Invention S The invention is a system and method for remotely controlling an ~u~ono~ us vehicle. The vehicle inr,hl(les a navigator, a ,~,~rhi~ control module, an engine control module, a ~ siol- control module and other ~lellls to permit autonomous operation. In aulo,-o...oll~ mode, the navigator produces a speed comm~n~ and a ~.~ angle co.~ n~l for the vehicle.
The m~rhin~ control module leCeiVeS the speed and ~ p angle co.. ~ s from the navigator and produces an engine RPM (revolutions per minute) control signal, a tr~n.cmic.cion control signal, a brake control signal, and a s~erin_ angle control signal to control the lower-level system of the vehicle.
The engine control module controls an RPM of the engine of the vehicle in response to the RPM control signal. The ~ .. icsion control module controls a gear selection in a ~l~".~,..i~cion of the vehicle in response to the ~ C...i.csion control signal.
In tele-operation mode, a tele-panel co~ rAIes the speed and St~l illg angle co... ~ lc to the navigator via a radio link. The navigator then provides these co.... "~ (1c to the m~rhin~ control module to operate the vehicle. Remote control or tele-operation is initi~te~ by establishing radio co.,l"..,llirations with the vehicle navigator using the tele-panel. The tele-panel tr~ncmi~c a vehicle identifier and a tele-panel i~lentifier to the vehicle.
Upon receiving co-------,~ tions from the tele-panel, the vehicle will cease a~llollolnous operation and enter a tele-ready mode. In the tele-ready mode, the vehicle will not respond to comm~n~s from other tele-panels and cannot resume autonomous operation. From the tele-ready mode, the tele-panel can CAT Ref: 93-514 SKGhF Rcf: 1245.047 - 215S2~ 2 instruct the vehicle to enter a tele-operation mode in which the vehicle is responsive to speed and steering angle requests from the tele-panel.
When in the tele-ready or tele-operation modes, the vehicle will not respond to co.~ s from any tele-panel except for the tele-panel identifi~3 S by the tele-panel i-lentifi~r. This prevents conflir,tin~ messages being sent to a vehicle by more than one tele-panel and assures that control of the vehicle always remains with the tele-panel which first establishes co~ ir~tion.
If co.~ ;rAlions between the vehicle and the tele-panel i-lrntifi~l by the tele-panel i~rntifi~r are ill~llu~t~d while the vehicle is in the tele-operation mode, the vehicle will ;I~IIII~1;AIe1Y halt and enter a locked state.
In the locked state, alulo~ ous operation and control by other tele-panels is p~ ed. The locked mode provides a l"~ocllA,~i~--- by which an ope~ator may intentionally halt the vehicle and approach it without concern that it will be moved under aulo~ol~ous control or under control by another tele-panel.
If co-~ -;r~tions between the vehicle and the tele-panel it1entifird by the tele-panel iderltifi~r are inlellupted while the vehicle is in the tele-ready mode, the vehicle is released and aulol~o.llous operation or control by another tele-panel is allowed (i.e., not pçev~ll~d).
The tele-panel of the invention includes an opc.ator interface panel, an elecll. nics module, a radio ~ scei~,~ . and an All~ The operator intrrfa~
panel inrll~des a number of ~will;h~s/controls which allow an ope~alor to control the vehicle. The switches/controls are input to the electronics module.
The ele~ onics module then produces a data packet for tlA.-s.~ission to the vehicle. The data packets are tr~n~ l to the vehicle by the transceiver ten times per second.
In the llrefe.l~d embodimrnt~ the operator interface panel includes an eme~gelh;y stop switch, a truck selector switch, a transmit switch, a mode select switch, a horn button, a dump switch (for use with an autonomous dump truck), an engine kill switch, and a speed/steering controller. Two CAT Ref~ 514 SKG&F Ref. 1246.047 -21S52~ 2 in-lic~tor lights provide an in-ljc~tion of whether power is provided to the tele-panel and whether the tele-panel is tr~ncmitting.
The fol~;goi~g and other fed~ s and advantages of the invention will be ap~ale.lL from the following, more particular dcs~;-ipLion of a pl~f~lcd embodiment of the invention, as illustrated in the accompdllyiQg dlawiugs.

Brief Description of the Figures FIG. 1 is a high level block ~i~gr~m sl~willg the a~lloll~ous vehicle system of the invention;
FIG. 2 is a flow chart ill~ al;n~ the steps involved in ~wiLehin~, operation of a vehicle b~l~n m~ml~l, aulo-l~lllous and tele modes of operation;
FIG. 3 is a block diagram illUSLlali..g the structure of a tele-panel and a vehicle with which the tele-panel co,-",~ icales;
FIG. 4 is a diagram of the tele-panel of the invention sllo-w-u~, the ope~lor interface panel; and FIG. S is a diagram illustrating the bytes of infolll,ation in a data packet 500 accor~ing to the invention.

Detailed Description of the Preferred Embo~iment The ~l~fellcd emb~lim~-nt of the invention is ~ sso~ in detail below. While specific part numbers and confi~ ;ons are ~iC~ se~ it should be understood that this is done for illustration ~ul~oses only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the invention.
The pl~,felled embodiment of the invention is now described with ~felel~ce to the figures where like ler~,el~ce numbers in~iic~te like elemPnt~.
In addition, the left-most digit of each lefe~nce number inr~ic~tçs the figure in which the number is first uæd.
CAT Rcf~ 514 SlCGkF RCf: 1246.047 -System Overview Figure 1 is a high level block diagram showing an autonomous vehicle system 100. Autonomous vehicle system 100 inrl~ldes a fleet manager 102, a vehicle control system 104 and a tele-operation panel 106. Fleet manager 102 is configured to manage a fleet of au~ o~lous mining vehicles such as dump trucks. Fleet manager 102 acts like a forell~ signin~ tasks to the mining vehicles and tracking their ~IUglCSs as they pc.rollll these tasks. Fleetmanager 102 co,-"""";r~tes with each vehicle via a radio link 108. Each vehicle inr~ es an on-board vehicle control system 104. Vehicle control system 104 pe.. "il~ autonomous operation of the mining vehicle under the control of fleet manager 102. Vehicle control system 104 inrlll(les a navigator 120, a truck reference unit (TRU) 122, an obstacle detector 124, a m~rllin~
control m~dlll~ (MCM) 126, and a~l~,~ced diesel engine manager (ADEM) 128, an electronic prûa, ~".l~ble ~ ...i.c.~ion control (EPTC) 130, and a vital hlrollll~Lion management system (V~S) 132.
Navigator 120 r~;~s instructions from fleet lll~ger 102 via radio link 108. The instructions include, for example, a work ~Siglllll~llL or task.
From the task, navigator 120 dete ,llin,s a route to be followed. The route may be, for e~ample, a haul segment btlwæn an excavation site and a crusher site in an open pit mining operation.
TRU 122 deL~ s the actual position of the vehicle using the global positioning system (GPS) and an inertial r~f. .~,lce unit aRU). Based on the actual position and the desired route, navigator 120 gel~ates a desired steering angle and a desired speed for the vehicle. Obstacle detector 124 is a radar unit which scans the area in front of the vehicle for obstacles. When obstacle detector 124 detects an obstacle, it provides an in-lic~tion that an obstacle is detected and/or the location of the obstacle to navigator 120.
Navigator 120 may then stop the vehicle or navigate around the obstacle.

CAT R~f~ 514 SKGhF Ref: 1246.047 Operation of fleet manager 102, navigator 120, TRU læ (also known as a "vehicle positioning system") and obstacle detector 124 are described in detail in the '540 application which is incol~olated by l~fe,e,~ce above.
Navigator 120, TRU 122 and obstacle detector 124 lc~lcsellL on-board S intelligence for the vehicle which allows autonomous control comm~n-ls to be generated in the form of the speed and steering angle co.. ~ s.
~ltf~rn~tively, tele-panel 106 may be used to co~ lunicate, via radio signals as i~ l at 110, steer angle, speed and other colllll~ s dil~lly to navigator 120 to allow remote control or tele-operation of the vehicle. In either case, before i1ulol-o~.nus or tele-operation can be achieved, the speed and sl~ ;.-g angle (as well as other co.. ~ s) must be serviced.
As ~et~iled in the above-lefc,e~ced patent application, MCM 126 rocei~s the steering and speed co~ s (and other co....-~ such as dump bed, sound horn, flash lights, etc.) from navigator 120 over a data bus 152.
MCM 126 then controls the vehicle's system to carry out the actions req )este(l by navigator 120. MCM 126 provides status and diagnostic inrollllation for the vehicle systems (e.g., ~hf- l..P, brakes, dump body, engine, t~ icsiQn~
etc.) to navigator 120 over data bus 152. MCM 126 controls the vehicle with the aid of ADEM 128 and EPTC 130. MCM 126 provides molli~olil~g and diagnostic infol~lion to navigator 120 with the aid of VIMS 132. In addition, VIMS 132 provides mo..;lo~ and diagnostic i~o....~lion dir~
- to navigator 120 over a data bus lS4.
ADEM 128 controls the speed or RPM (revolutions per minute) of the vehicle's engine. EPTC 130 controls gear selection in the ~L~.,.C.,,i~ion and ensures that the tr~n~mi~sion is in the correct gear. VIMS 132 monitors di~~ systems of the vehicle.
Vehicle control system 104 includes three modes of vehicle operatio~.
These include autonomous mode, manual mode and tele-operation mode.
Each of these modes is ~i~c~1sse-1 below.

CAT Rcf~ 514 SKG~F Rcf: 1246.047 215~2~2 Autonomous Operahon To achieve autonomous operation of the vehicle, the steering angle Co~ -A~ and the speed co....-~And from navigator 120 must be A..~ ,d by adju~,~in~ the st~ring angle and speed of the vehicle. MCM 126 COIn~ e.S the S speed reql~est~d by navigator 120 with the actual vehicle speed and adjusts the vehicle speed, if required, by sen-~ing apl)~plia~ signals to ADEM 128, EPTC 130 and the vehicle's braking system. MCM 126 co.-.~ -ir~tes these instructions to ADEM 128 and EPTC 130 over a data link 134. In addition, VIMS 132 l~o~ oli the status of ADEM 128 and EPTC 130 over, and provides mouilol~d ~AI,.III. t~ to MCM 126 over, data link 134. In the pl~Ç~lled embo~lim~nt, data link 134 is a serial data bus such as a CAT Data Link, available from Caterpillar Inc.
MCM 126 co--~ atçs an RPM control signal to ADEM 128 over data link 134 to control engine speed. A second RPM control signal is also ænt to ADEM 128 over a l~ dz.lt line 136.
MCM 126 co--~------~ir~es a ~ csion control signal to EPTC 130 over data link 134 to ælect the top gear and direction (i.e., fOl~al~d or reverse) of the ~ ion. The vehicle has an a.~lo...~l ;c trAncmi.~sion whichis controlled by EPIC 130. The trAn.~mi~sion control signal limits the top gear which may be used by the l . ~ ;on and selects the direction of travel - for the vehicle.
In conj.~ ;on with controlling vehicle speed, MCM 126 controls the braking system. In the p~r~,lçed embod ent of the invention, the vehicle braking system inrhldes a pAIl~ g brake, a service brake/retarder system, and a secondary brake. MCM 126 controls these dirr.,lell~ brakes directly via control line 138 which ~ctn~tes solenoid valves to control air ~l~,s~ule in the three Sy~ S. For e~a~le, when navigator 120 requests a speed lower than the present speed, MCM 126 decides whether the lower speed should be achieved by reducing engine RPM and/or by applying the service brakes. If CAT Ref~ 514 SRG~F Ref: 1246.047 -- 215~2S2 braking is required, MCM 126 applies the brake in a smooth manner to avoid locking up the wheels.
In response to the s~ling angle co.-....q~ from navigator 120, MCM
126 directly controls the vehicle's ~ by scl~ding right steer and left steer signals 140 to solenoids which control stLel~g.
In the plefelled embodiment of the invention, autonomous vehicle system 100 is used to implement an au~onomous haulage system. Using a number of dump trucks (such as the Caterpillar 777C), the hqllla~e system is configured to carry a mqt~nql such as rock from an e~cdvdlion site to a crusher site. To permit fully au~ ls oper~tion of the vehicle, MCM 126 controls other fea~ul~ s of the vehicle, such as du~ ~g of the truck body or bed. MCM 126 produces a dump signal 142 which actll~t~s the hydraulic system of the vehicle to raise and lower the vehicle body. For safety considerations, MCM 126 also controls au~iliary functions of the vehicle such as the horn, lights and backup alarrn vha an ?llsiliqry control line 144.
Thus, during ~ onol~nls operation, MCM 126 i~ ly controls the engine and trqn~mi~sion vh ADEM 128 and EPTC 130. MCM 126 di~lly controls the vehicle's braking ~y~ us, steering, body (i.e., raise or lower), lights (in-.hl-lin~ head lights and aul~onlous operation strobe ~all~il~g lights), horn and back-up alarm.

a~ Oper~tion MCM 126 implements aulo~ ous operation of a vehicle. It is desirable, however, to also perrnit manual operation of the vehicle. In a manual mode of operation, the aulollGIIlous control fealules should be ll~s~ ~ and not affect normal functioning of the vehicle. Moreover, for safety, swi~hing belween an aulo~o~ous, tele (remote control) and manual modes of operation must be tightly controlled so that the vehicle ~nlaills in control at all times. The structure and operation of MCM 126 which impl.om~nt~ these f~ allnes of the invention are described below.

CAT Ref~ 514 SKG&F Ref: 1246.047 21~2S2 g MCM 126 permits manual operation by relin~ hin~ control of the vehicle sub~y~ s to an operator. In manual mode, ADEM 128 receives the speed co~ from an ope~a~ol ~ct~ted throKle or accelerator pedal 144.
Similarly, EPTC 130 receives top gear ælection and direction co.. ~.uls from a shift cane 146 controlled by the O~latOl. Brakes and ~l~ are m~ml~lly controlled by the O~.atOl using a conventional steering wheel and brake pedal. The body is controlled by a switch which acl~AI~s a solenoid in the hydraulic system.
During _anual operation, MCM 126 will continue to IllOIlit~l system parameters but will not in~Lr~Le with control of the vehicle in any way.

Tele-Operahon In tele-operation of the vehicle, the ~ ing angle co~ zn~l and the speed comm~n l from navigator 120 origin~tf~ from tele-panel 106 via radio link 110. These co.. ~ s are then sent to MCM 126 as with aulon~n~ s operation. From the ~.~pec~i~/e of MCM 126, ~ulo~lolllous and tele-ope~ on modes are i~llonti~l Trn~lsitioning Between Modes of Operation MCM 126 defaults to manual mode at power-up. Manual mode is in~lirate-l to ADEM 128 and EPTC 130 via an auto/manual select signal sent over an auto/~m~m-~l control line (AMCL) 150. For example, AMCL 150 is pulled HIGH by ADEM 128 and EPTC 130. When AMCL 150 is high, manual mode is inrlir~ted to ADEM 128 and EPTC 130. If autonomous mode is desired, MCM 126 will in~ te this to ADEM 128 and AMCL 150 by pulling AMCL 150 LOW.
Transition into autol~lous mode will only take place if the following conditions are met:
(1) vehicle speed is zero;

(2) pa~ g brake is on;
CAT Ref~ 514 SKG&F Ref: 1246.047 `- 21~2~2 (3) shift cane 146 is in neutral;

(4) a first auto/manual switch (located in the cab of the vehicle) is ~wi~hed to ~ulO~ OuS mode; and (5) a second auto/manual switch (located near the ground on, for example, the front l,u~u~r of the vehicle) is switched to aulolloll.ous mode.

If these five conditions are met, MCM 126 will send an auto enable signal to navigator 120 over data bus 152. If navigator 120 is sqti~fi~od that all ~t~,.llS
are filn-~tionin~ pr~pelly (based on status i~ol~tion provided by MCM 126 and VIMS 154), navigator 120 will send an auto mode signal back to MCM
126. Upon receipt of the return auto mode signal from navigator 120, MCM
126 will enter the aulol~mous mode. This involves MCM 126 ~wil~hi.lg ADEM 128 and EPTC 130 into autonomous mode by placing the proper signal on AMCL 150 (e.g., by pulling AMCL 150 low). The vehicle controls (e.g., ADEM 128 and EPTC 130) will then be ready to receive i~lluclions from MCM 126, which in turn waits to receive instructions from navigator 120.
Once the vehicle is in autonomous mode, it will not switch back to manual mode until several conditions exist. These conditions reduce the possibility of the vehicle coming out of autonomous mode in anunsafe .. ~ f-r (e.g., while traveling at speed). Before the vehicle can switch from ~ulo~ ous mode to manual mode, the following conditions must exist:
(1) vehicle speed is zero;
(2) parking brake is on;
(3) shift cane 146 is in neutral;
(4) engine RPM is at low idle; and (5) both the first and second auto/manual switches are in the manual position.

CAT Ref~ 514 SKG&F Ref: 1246.047 21552~ 2 When these conditions exist, MCM 126 will place ADEM 128 and EPTC 130 in manual mode via AMCL 150. MCM 126 will also de-actuate all solenoid drivers used to control other functions of the vehicle, such as the body, auxiliary functions, brakes and st~~ g.
S Tele-operation mode can only be entered from the autonomous mode.
Tele-operation mode cannot be entered di~;lly from manual mode. In tele-operation mode, vehicle control system 104 will behave identicAlly to the autonomous mode described above except that navigator 120 will receive a speed co.. ~.~l, a ~t~ ;.. ~ angle co.. ~ and certain ~nYili~ry co.~ s (~esr-rihed below) from tele-panel 106 rather than ge~d~ these cG.. An~ls on its own.
Figure 2 is a simplified block diagram illusllatillg the steps followed in transitioning bel~. ell the modes of vehicle operation. Manual operation is in-lirate~l at block 202, ~u~O~O~luus operation is i~ulir~l~ at block 214 and tele-opçr~tion mode is i~ tP~1 at block 220. As in-lir~t~ above, m~ml~l operation 202 is the default of MCM 126 upon power-up. If it is desired to switch into the dUlOl1olllous operation mode and each of the con-1ition~ listed above is met, MCM 126 will cycle through steps 204-212 before re~ ing autonomous mode 214.
First, a speed self-test is eYec~lt~d as i~--lir~led by block204. The speed self-test checks data link 134 to assure that it is ope~ g yro~,ly and that ADEM 128 and EPTC 130 can be controlled by MCM 126. In addition, MCM 126 checks for brake ples~ul., and assures that the brakes can be controlled. Next, in at block 206, a ~ -ng self-test is pel~l---ed. In the steering self-test, the wheels of the vehicle are moved to assure that sl~ elil-g can be controlled, and that the change in the steering angle can be sensed.
In block 208, a wait state is entered. In the prefelled embo-lim~nt a five second pause is eY.ocl~te~ At the beginning of the pause, the horn is honked and strobe lights are turned ON to warn any person near the vehicle that autonomous operation is being enabled. Thereafter, the vehicle enters an CAT Ref~ 514 SKG~F Ref: 1246.047 - ~ 215~252 auto-ready mode as inrl*~te~ at block 210. In the auto-ready mode, MCM
126 is in control of the speed and the steering of the vehicle. The steering angle is set to zero degrees and the speed is m~int~in~d at zero miles per hour. At this auto-ready state, the vehicle is essentiqlly in autonomous mode with navigator 120 telling the vehicle to do notl~u~g.
The vehicle will remain in auto-ready mode until a valid co.. ~tl is received from navigator 120. Once a valid co.. ~ l is received, MCM 126 will enter a second wait state as intlic~ted at block 212. The second wait stateis similar to the first. The horn is again honked and the strobe lights remain 10on from the first wait state. This wait state is provided to warn anyone in the vicinity of the vehicle that the vehicle will be moving soon. At the conclusion of this second wait state, the co.. ~ from navigator 120 is eYPcllte~ to fullyenter ~ulo~ ous mode as in-lic~tfA at block 214.
If the speed self test at block 204 or the s~ self test at block 206 15fails, or if either of the auto/manual control ~wi~hes are toggled to mqnn~l mode during ~len~ing through blocks 208-212, MCM 126 will abort the changeo~ l to aulo~ ous operation and will proceed dh~;lly to a tr~nC;tion mode of block 216. Transition performs an orderly shut-down which includes that the vehicle speed is zero, the p~ brake is on, and the 20!.,.I~ sion is in neutral. The vehicle will stay in tr~n~ition mode until bothof the auto/mqml~l control swil~,hes are swi~hed to m~mlql mode. At that point, the vehicle can return to manual operation as in~ t~1 at block 202.
At any time during autonomous operation (block 214), tele-operation may be initi~ted. Tele-operation is initi~t~A by tele-panel 106 establishing co------.-"i-~tions with navigator 120. Establishing co.. ~ ions will cause navigator 120 to imme~ tt~ly stop the vehicle and enter a tele-ready mode as ed at block 218. In the tele-ready mode, tele-panel 106 has control of the vehicle and l~ -iL~ comm~n~l~ for æro speed and æro steer angle.
Tele-panel 106 then transmits a tele-operation request signal. This 30signal causes vehicle control system 104 to enter tele-operation mode as CAT Rcf~ 514 SKChF Ref: 1246.047 21552~2 intiit~te~ at block 220. In tele-operation mode, the vehicle will respond to co,-~"~ s from tele-panel 106.
As noted above, tele-operation can only be initiqt~d from autonomous mode. Recq,~lse the auto-ready mode in-iicqtP,d at block 210 is ess~ntiqlly partS of aulollolllous operation, tele-operation can be inhiqted from this auto-ready state. In that case, the valid co"""-q-n-l from navigator 120 which i~ tes wait state 212 will actually originate from tele-panel 106.
If co""~ qtions be~weell vehicle control system 104 (more specirlcally, navigator 120) and tele-panel 106 are illt~ u~ted while the vehicle is in the tele-operation mode, vehicle control system 104 will enter a locked state as in~i~qt~3 by block 2æ. In the locked state, ~uk)llolllous operation is prevented. In addition, the vehicle will not respond to co,~ C
from any other tele-panel (as iiccllssed below, each tele-panel has a unique identifi~r). The vehicle will remain in the locked state until co"""~ al;ons with the ori~inql tele-panel are re-established. At that time, tele-op~o~qtion is re~lm~ at block 220.
Aulollolnous operation at block 214 can only be Le.~ by plo~lly exiting tele-operation mode. This involves se~ n~ a tele-ready mode request signal to cause vehicle control system 104 to enter the tele-ready mode of block 218. From tele-ready mode 218, auLol-. ",Ollc operation at block 214 can be entered by discol~ co.. ~ ;ons from tele-panel 106.

Comntrrnie~rtiQn between Tele-panel 106 and Na~lgulor 120 Tele-panel 106 co""",l.-i~-q-~s with navigator 120 via a radio link. This is illustrated in Figure 3. Tele-panel 106 includes an electronics module 302, a data radio 304 and an q.-,le~ 306. Vehicle control system 104 intlu~ie~c an qi~lr.~n~ 308 and a data radio 310 for l~ceivh~g tele-operation signals from tele-panel 106. Data radios 304,310 and ~ ",~c 306,308 form a co"""~i-ir~tions link through which tele-comm~n~lc from electronics module 302 are co~ ~icated to navigator 120. The tele-colllll~luls sent to the CAT Ref~ 514 SKG~F Ref: 1246.047 - - 21552~2 navigator are in a data format id~Pntir-~l to the format used by the navigator in the coln""~ c that it provides to MCM 126.
Electronics module 302 is a microprocessor-based controller which includes a Motorola 6XHCllK4 microcontroller available from Motorola Inc.
S of Srh~l-mhurg, Illinois. A microcontroller of this type in~ln-1~Ps a microp~cessol, a read only memory (ROM), a random access memory (RAM) and an input buffer circuit. In the plc~llcd embo~imPnt, radios 304,310 are 800 MHz frequency mod~ tP~d, high-speed data ~la~ ;vcls available from GLB Inc., Buffalo, New York.
Figure 4 i~ i.tes opcldtor intPrf~ panel 301 of tele-panel 106.
Elec~ ~ics module 302 is cont~inP~ with ope,à~or i~.Lcc panel 301.
TntPrf~re panel 301 inl~ludçs an emc,g~ll~ stop switch 404, a vehicle selector switch 406, a power ~ tQr light 408, a transmit in~ic~tor light 410, a t~An.cmit switch 412, a mode select switch 414, a horn switch 416, a bed raise/lower switch 418, an engine start/stop switch 420 and a speed/~t~;,¢
control 422. Each switch/control provides an input to el~cl,onics m~hlle 302.
Each in~ic~tor light 408,410 is driven by elecllomcs module 302. Based on the positions of the various swi~hes, electronics module 302 foln~t~ a data packet to be IIAI~ by radio 304 to the vehicle.
~ltr~e~ stop switch 404 provides a "panic" stop button. If depl- ,,sed, switch 404 will cause the vehicle to come to an ;,llll~ t~ stop.
Vehicle selector switch 406 is a rotary switch used to select the vehicle which tele-panel 106 will control. As tiiccllcce~1 below, each vehicle has a unique id~ntiflcation (ID) number. Tlal~lllil switch 412 is a single pole toggle switchused to turn on llA~ sion by tele-panel 106. Mode select switch 414 is a single pole toggle switch used to select belw~n tele-ready mode 218 and tele-operation mode 220. Horn button 416 is a molllel~ , normally open, push button switch used to sound the horn of the selectçd vehicle. Switch 418 is a single pole toggle switch used to raise/lower the bed of a dump truck in the CAT Ref~ 5t4 SKGhF Ref: 1246.047 - - 21~S2~2 p,efell~d embodiment of the invention. Switch 420 is a single pole toggle switch for turning the vehicle's engine on or off.
In the p~ef~ d embo~im~ont toggle ~ ;hes 412, 414, 418 and 420 have pfolecli~e covers to prevent them from being inad~,~lte.llly toggled.
S Ful~lellllore, the covers for transmit switch 412 and mode select switch 414 will bump those switches to an off position when closed. For transmit switch 412, the off position coll~,spollds to transmit off. For mode select switch 414,the off position corresponds to the tele-ready mode.
Speed/~ control 422 is a two-axis joy stick used to control the speed and ~l~ri-~ for the vehicle. Moving the joy stick fo~ ,a~S the vehicle's folwa~d speed. Moving the joy stick in a reverse direction will increase the vehicle's reverse direction speed. Moving the joy stick to the leftwill cause the vehicle to steer left, and moving the joy stick to the right willcause the vehicle to steer right.
T"~ or light 408 in~ tes whether power is being supplied to tele-panel 106. Tn~ tor light 410 i~ c~les v~L~cr tele-panel 106 is In the pref~lled embodiment, electronics mo~lllle 302 provides a data packet to Mdio 304 ten times per second for ll~".~i",i~;on- This data packet is then broadcast to navigator 120 via the radio link. The contents of each data packet is controlled by the positions of the various panel controls 404, 406, 412, 414, 416, 418, 420 and 4æ. As set forth above, eleellol~ics module 302 includes a microcontroller, such as the Motorola 68HCllK4.
The various panel controls of ullt;lr~ce panel 301 are connected directly to an input buffer of the microcontroller. The microcontroller produces the data packet co~ in~ co"""~ 1s based on the positions of the various panel controls.
The format of the tr~n~mitted data packet is illllstr~ted in Figure 5.
Each data packet 500 includes eleven bytes of information. These include a start byte 502, a vehicle ID byte 504, a panel ID byte 506, a mode byte 508, CAT Ref~ 514 SlCGhF Ref: 1246.047 - 21~252 a speed byte 510, a steering byte 512, an auxiliary byte 514, two unused bytes 516 and 518, a check sum byte 520 and an end byte 522. Each of these is ~i~cussed in detail below:

Byte F~ nct;on S Start 502 This byte in-lic~t~s beghll~ing of data packet.
Vehicle ID 504 This byte idP ~lili~s the vehicle to which the message is directed.
Panel ID 506 This byte ;~ r-~cs the i~ ion n--m~r for the tcle-panel. Each tele-panel has a unique i~le~.l;.~.~;on number.
Mode 508 This byte intli-~t~s wllc~ r tele-ready mode or tele-operation mode is request~.
Speed 510 This byte in~1icates a desired vehicle speed.
5l~r~ 512 This byte i-~ tl,s a desired vehicle st~
angle.
Auxiliary 514 This byte in-iieat~s, for e~mple, ~llc ll~r a dump truck's bed should be raised or lowered and whether the horn should be sounded.
Not Used 516 and These bytes are not used for data but are present Not Used 518 in the data packet to keep the packet format col~is~clll with what MCM 126 receives from navigator 120. This co~ t~ .~ format allows the navigator to pass the data packet di~clly on to MCM 126 for control of the vehicle's various lclllS;
Check Sum 520 This byte is a modulo 256 ~ ;on of the first nine bytes of the data packet. It is used for error detection.
End 522 This byte in~lic~tes the end of the data packet.

CAT Ref~ 514 SKG~F Ref: 1246.047 - 21~25 2 Operation of Tele-panel 106 If it is desired to take control of a vehicle which is opelatiL~g autonomously, an o~lator proceeds as follows. First, the opelator uses vehicle selector switch 406 to select a vehicle to be controlled. Next, the operator toggles transmit switch 412 to turn transmit on. This will cause the selçcte~ vehicle to h~ ediaLely halt and standby (in tele-ready mode 218) for further instructions from the tr~ncmittin~ tele-panel 106.
Next, the opel~alor toggles mode select switch 414 to tele-o~ldlion.
This a~ ales the ~wilch~s and controls on the face of hltelrdce panel 301 so that input from steering/speed controller 422 controls the data in speed and steering bytes 510,512 and so that the ~wi~hes 416, 418 and 420 control the data in allxili~ry byte 514. In tele-operation mode, navigator 120 will pass thedata packets received from the tele-panel dh~lly to MCM 126. MCM 126 then control the vehicle's sl~,e.il~g, speed and auxiliary functions based on the data contained in data ~ac~ 500.
To ~ro~lly release the vehicle from tele-control, an o~lator stops ~he vehicle via speed/~l~el~g control 422, toggles mode select switch 414 to tele-ready mode 218 and then turns off ~ switch 412. Once the L~
switch is turned off, navigator 120 is released to resume autonomous operation or control by another tele-panel.
A second tele-panel will not be ~....i~led to take control of a vehicle while the ~al~sl~ switch of a first tele-panel is still in the on position (i.e., the vehicle is lecei~ g data packets from the first tele-panel). The unique tele-panel i(irntifiç~tion ~ ...iLIe~ in the first data packet received by the vehicle is stored in a memory within navigator 120. Each sllbseq~lent data packet is then rll~qr~l to assure that it is from the same tele-panel. This feature assures positive control of a vehicle at all times.
If at any time during tele-operation of a vehicle, the signal tr~ncmitted by the tele-panel is lost, the vehicle will immedi~tely stop and enter locked state 222. This might occur, for example, if transmit switch 412 is turned off CAT Ref: 93-514 SKGhF Rtf: 1246.047 21SS2~ 2 while mode select switch 414 in~ic~tes tele-operation. In the locked state, autollolllous operation is prevented and tele-operation from other tele-panels is ~ ,.l~d. The vehicle can only exit the locked state by re-establishing CO~ r n~ with the origin~l tele-panel.
This feature further pl~vt;llls ambiguity of control. I~ .. ore, this feature can be used to intentionally lock an ~,lo,-o.-~ous vehicle. For example, in an au~o,lo,l,ous mining operation, a m~cl~ may want to approach an aulO~ OUS truck for service. By using the tele-panel to stop and lock the vehicle before app~ac~;n~ it, he can guard his pe.~oual safety. Once he has applvach~d the vehicle, he may place it in manual mode 202 or I . al~ ;on mode 216 using the auto/manual select switch located on the 1,~
of the truck to further assure that it will not move during the service.
While the invention has been particularly shown and described with l~fe~ce to several plcf~,lç~d embol;--~ thereof, it will be Im~1erstood by those skilled in the art that various ch~ng~s in form and details _ay be made therein without depa,~i~g from the spirit and scope of the i"~lion as defined in the appended claims.

CAT Rcf~ 514 SKG~F Ref: 1246.047

Claims

1. A method for remotely controlling an autonomous vehicle, comprising;
establishing radio communications with the vehicle via a tele-panel, wherein a vehicle identifier and a tele-panel identifier are transmitted to the vehicle, and wherein establishing radio communications ceases autonomous operation of the vehicle and places the vehicle in a tele-ready mode in which the vehicle will not respond to commands from other tele-panels;
communicating a tele-operation request signal to the vehicle, said tele-operation request signal placing the vehicle in a tele-operation mode in which the vehicle is responsive to speed and steering angle requests from said tele-panel;
if communications between the vehicle and said tele-panel identifier by said tele-panel identifier are interrupted while the vehicle is in said tele-operation mode, halting operation of the vehicle, not allowing autonomous operation of the vehicle, and not allowing control of the vehicle by any other tele-panel; and if communications between the vehicle and said tele-panel identified by said tele-panel identifier are interrupted while the vehicle is in said tele-ready mode, not preventing autonomous operation of the vehicle and not preventing control of the vehicle by another tele-panel.

2. The method of claim 1, wherein said step of establishing radio communications comprises:
transmitting data packets from said tele-panel to said vehicle, each data packetincluding a vehicle identification byte, a tele-panel identification byte, a mode byte, a speed byte, and a steering byte.

3. The method of claim 2, wherein said step of transmitting data packets comprises:
transmitting data packets at least ten times per second using a frequency modulation scheme and a continuous carrier wave.

4. The method of claim 1, wherein said step of establishing radio communications comprises:
transmitting data packets from said tele-panel to said vehicle, each data packetincluding a start byte, a vehicle identification byte, a tele-panel identification byte, a mode byte, a speed byte, a steering byte, an auxiliary byte, a check byte and an end byte.

5. The method of claim 4, wherein said step of transmitting data packets comprises:
data packet at least ten times per second using a frequency modulation scheme and a continuous carrier wave.

6. The method of claim 1, further comprising a step before said step of establishing radio communications of:
selecting via said tele-panel a vehicle to be controlled from a plurality of such vehicles.

7. A system for remotely controlling an autonomous vehicle, comprising:
a tele-panel having control means for allowing an operator to generate speed and steering angle commands, mode select means for allowing an operator to select an operational mode of said vehicle, processor means for receiving said speed and steering angle commands from said control means and said selected operational mode from said mode select means, for generating a vehicle identifier and a tele-panel identifier, and for formatting said vehicle identifier, said tele-panel identifier, said selected operational mode, and said speed and steering angle commands into a data packet, and transmitter means for establishing communications with the vehicle and for transmitting said data packet to the vehicle; and vehicle control means, mounted on said vehicle, for receiving said communications from said tele-panel and for controlling operation of the vehicle in response thereto, said receiver means having receiver means for receiving said communications from said transmitter means, mode set means for placing the vehicle in a tele-ready mode in response to said data packet receiver from said tele-panel and for placing the vehicle in tele-operation mode when said selected operational mode of said data packet indicates tele-operation mode, means for producing vehicle speed and steering angle control signals in response to speed and steering angle commands in said data packet, and means for halting operation of the vehicle, not allowing autonomous operation of the vehicle, and not allowing control of the vehicle by another tele-panel if communications between the vehicle and said tele-panel identified by said tele-panel identifier are interrupted while the vehicle is in said tele-operation mode.

8. The system of claim 7, wherein said control means is a two-axis joy stick.

9. The system of claim 8, wherein said mode select means is a switch allowing selection of either autonomous mode or tele-operation mode.

10. The system of claim 9, wherein said processor means is a microcontroller .

11. The system of claim 10, wherein said transmitter means is a high speed data transceiver.

12. The system of claim 11, wherein said receiver means is a high speed data transceiver.

13. The system of claim 12, wherein said mode set means and said means for halting comprise a vehicle navigator.

14. The system of claim 13, wherein said means for producing vehicle speed and steering angle control signals comprises a machine control module.